All Potato Alerts - Pacific Northwest Pest Alert Network

2024 Miller Research Potato Pest Management Seminar Handouts

Potato All Locations

Posted on: April 15, 2024 by Jeff Miller

The 2024 Miller Research Potato Pest Management Seminar was held on February 21 at the Historic Wilson Theater in Rupert, ID. Handouts from the presentations are now available at the attached link.

» https://millerresearch.com/2024/04/2024-miller-research-potato-pest-management-meeting/

ICIA Seed Seminar - January 16, 2024 - Red Lion Hotel - Pocatello, Idaho

Potato All Locations

General announcement

Posted on: January 10, 2024 by Kasia Duellman

Dear All:

I have been remiss in passing on this information regarding the Annual ICIA Seed Seminar that precedes the Idaho Potato Conference, sponsored by the Idaho Crop Improvement Association. Please forgive me - the deadline for early registration has passed, but you can register at the door on the day of the event.

Date: January 16, 2024

Time: Seed Seminar - 11:30AM to 3:45PM (a closed PAC meeting follows, from 3:45PM to 5:00PM)

Location: Red Lion Hotel, 1555 Pocatello Creek Road, Pocatello, Idaho

For questions, please contact Ruby Hall at ICIA via email (rhall@idahocrop.com) or phone (208-522-9198).

Please see attached the registration form and the agenda.

Sincerely,

Kasia

» ICIA Seed Seminar Agenda

» ICIA Seed Seminar Registration

University of Idaho Potato Storage Open House

Potato All Locations

Posted on: November 6, 2023 by Gustavo Teixeira

Potato Enthusiasts -- Get ready for an extraordinary experience! You are warmly
invited to the inaugural University of Idaho Potato Storage Open House taking
place at the state-of-the-art Potato Storage Facility at the Kimberly Research
and Extension Center on December 5th, from 9:00 am to noon.

What's in Store for You? At this event, we're bridging the gap
between industry and cutting-edge U of I storage research, and we've packed the
morning with exciting activities:

Explore the Future: Witness the latest breakthroughs and
advancements in potato storage through captivating research posters and live
demonstrations.

Behind the Scenes: Step inside the innovative Potato Storage
Facility and see where the magic happens. Discover how this facility supports
our industry-related research and extension projects, contributing to your
economic growth.

Knowledge Exchange: Join our U of I researchers in lively
discussions about the most current potato research practices and industry
trends.

But that's not all! Your participation at the Open House will
not only be highly appreciated but also incredibly insightful and
rewarding.

Event Details:

Date: December 5th

Time: 9:00 am - noon

Location: Potato Storage Facility, Kimberly Research and
Extension Center

Don't miss out on this unique opportunity to connect, learn, and be a
part of the future of potato storage.

» Open_House_Flyer_2023.pdf

final report of the 2023 potato psyllid / Lso monitoring season.

Potato All Locations

potato psyllid

Posted on: September 21, 2023 by Tasha Stanzak

This is the final report of the 2023 potato psyllid / Lso monitoring season.

All of the psyllids tested last week were negative for Lso, the bacterium associated with zebra chip disease (ZC).

About 6% of all psyllids tested positive for Lso this year compared to around 1% in most recent years (and 22% last year).

It was another interesting year with somewhat high Lso incidence, but relatively low overall psyllid captures. Captures were only slightly higher than last year, which was among our lowest years ever. Thus, the risk of ZC likely was mitigated somewhat by low psyllid captures despite relatively high Lso.

Thanks again to all of our cooperators who helped to deploy and retrieve so very many yellow sticky traps! And thanks to the growers who let us use their fields for this work!

More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid trapping wrap up

Potato All Locations

potato psyllid

Posted on: September 14, 2023 by Tasha Stanzak

We officially ended the monitoring season last week, but we received a bonus week of sticky traps from two fields in Canyon County this week. We captured a total of 12 psyllids across these 2 fields.

None of the six psyllids captured last week was positive for Lso, the bacterium associated with zebra chip disease (ZC). Next week we will report Lso results for the 12 psyllids submitted this week and provide an end-of-season wrap up.

About 7% of all psyllids tested positive for Lso this year compared to around 1% in most recent years (and 22% last year). It is too soon to tell what this low psyllid / somewhat high Lso season means for ZC in tubers at harvest. Our studies in Russet Burbank showed that ZC can develop during storage if infection occurs as late as two weeks before vine kill. Please consider this in your late-season IPM programs. Risk could be mitigated by processing tubers from fields at higher risk sooner rather than later.

More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid trapping ends for the season.

Potato All Locations

potato psyllid

Posted on: September 7, 2023 by Tasha Stanzak

This week we received traps from 20 of the 55 fields that we are monitoring. Thirty-three fields have been vine killed or are senescing and are no longer being monitored. We captured a total of 6 psyllids across 3 fields. The three fields were in Canyon, Elmore, and Twin Falls counties.

This is our last week of actively trapping psyllids. We will post the final results next week to finish out the monitoring season.

One psyllid tested from last week’s Canyon County captures was positive for Lso, the bacterium associated with zebra chip disease (ZC); the rest of the psyllids captured last week were negative for Lso. This is the first Lso positive we have detected since early July.

With harvest season upon us, it is worth remembering that our studies in Russet Burbank showed that ZC can develop during storage if infection occurs as late as two weeks before vine kill. Please consider this in your late-season IPM programs. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid captures dropped this week

Potato All Locations

potato psyllid

Posted on: September 1, 2023 by Erik Wenninger

This week we received traps from 31 of the 55 fields that we are monitoring. Twenty-two fields have been vine killed or are senescing and are no longer being monitored. We captured a total of 15 psyllids across 7 fields. Five of the fields were in Canyon County, and the other two fields were in Elmore and Twin Falls counties.

Total psyllid captures dropped notably from last week. The slightly cooler temperatures and precipitation likely contributed to lower captures.

All psyllids tested from last week’s captures were negative for Lso, the bacterium associated with zebra chip disease (ZC); however, the results from the psyllids that arrived to us late are still pending. Interestingly, we still have not had a positive psyllid since early July.

With harvest season upon us, it is worth remembering that our studies in Russet Burbank showed that ZC can develop during storage if infection occurs as late as two weeks before vine kill. Please consider this in your late-season IPM programs. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid captures per field similar to last week

Potato All Locations

potato psyllid

Posted on: August 25, 2023 by Tasha Stanzak

This week we received traps from 35 of the 55 fields that we are monitoring. One field was vine killed and we are still waiting on traps from 19 sites. Many of these fields could not be entered earlier in the week so traps were shipped to us late. We captured a total of 30 psyllids across 10 fields. Four of the fields were in Canyon County; the remaining 6 fields were in Elmore, Gooding, and Twin Falls counties.

Total psyllid captures per field were similar to last week, though several of the fields still unaccounted for are sites where we’ve seen relatively high captures this season. Updated results will be posted on the sites (below) early next week, and we’ll send out another alert if anything unexpected is observed.

All psyllids tested from last week’s captures were negative for Lso, the bacterium associated with zebra chip disease (ZC). We have not had a positive psyllid since early July.

Nevertheless, we urge growers to have their IPM programs in place. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid captures tick up slightly, but still relatively low

Potato All Locations

potato psyllid

Posted on: August 17, 2023 by Erik Wenninger

This week we received traps from 49 of the 55 fields that we are monitoring. We captured a total of 44 psyllids across 14 fields. Ten of the fields were in Canyon County; the remaining 4 fields were in Payette, Elmore, and Twin Falls counties.

Total psyllid captures ticked up slightly, at least in the Treasure Valley; however, captures were still relatively low compared to previous years. This is the time of year that we typically see captures increase, so this uptick is not surprising.

All psyllids tested from last week’s captures were negative for Lso, the bacterium associated with zebra chip disease (ZC); results are pending for seven psyllids that were shipped late. Although we saw relatively high prevalence of Lso in early samples, we have not had a positive psyllid since early July.

Nevertheless, we urge growers to have their IPM programs in place. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid captures remain low; no new positives

Potato All Locations

potato psyllid

Posted on: August 10, 2023 by Erik Wenninger

This week we received traps from 50 of the 55 fields that we are monitoring. We captured a total of 30 psyllids across 12 fields. Seven of the fields were in Canyon County, the remaining 5 fields were in Payette, Owyhee, Elmore, and Twin Falls counties.

Total psyllid captures were similar to last week, and we continue to see quite low numbers this season.

All of the psyllids captured last week were negative for Lso, the bacterium associated with zebra chip disease (ZC). We still urge growers to have their IPM programs in place given the prevalence of Lso earlier in the season. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

» https://idahopestmonitoring.org/

Psyllid captures still relatively low

Potato All Locations

potato psyllid

Posted on: August 3, 2023 by Tasha Stanzak

This week we received traps from 46 of the 55 fields that we are monitoring. We captured a total of 29 psyllids across 13 fields. Nine of the fields were in Canyon County, the remaining 4 fields were in Payette, Owyhee, Gooding, and Twin Falls counties.

Total psyllid captures were slightly higher than last week, but we continue to see quite low numbers this season.

All of the psyllids captured last week were negative for Lso, the bacterium associated with zebra chip disease (ZC). This is good news considering the prevalence of positive psyllids during early July, but we still urge growers to have their IPM programs in place. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

» https://idahopestmonitoring.org/

No new positive psyllids this week

Potato All Locations

potato psyllid

Posted on: July 28, 2023 by Erik Wenninger

This week we received traps from 53 of the 55 fields that we are monitoring. We captured a total of 21 psyllids across 9 fields. Six of the fields were in Canyon County, the remaining 3 fields were in Payette, Owyhee, and Twin Falls counties.

Total psyllid captures were slightly higher than last week, but we continue to see quite low numbers this season.

All of the psyllids captured last week were negative for Lso, the bacterium associated with zebra chip disease (ZC). This is good news considering the prevalence of positive psyllids the last two weeks, but we still urge growers to have their IPM programs in place. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

» https://idahopestmonitoring.org/

More Lso-positive psyllids

Potato All Locations

potato psyllid

Posted on: July 20, 2023 by Tasha Stanzak

This week we received traps from 46 of the 55 fields that we are monitoring. We captured a total of 10 psyllids across 4 fields. Three of the fields were in Canyon County and one was in Twin Falls County.

Total psyllid captures were similar to last week, and we continue to see relatively low numbers this season.

However, 12 of the 14 psyllids we captured last week were positive for Lso, the bacterium associated with zebra chip disease (ZC). In addition, one of the three psyllids from the previous week that was shipped late also tested positive. Thus, 15 of the 19 psyllids tested this season have been positive.

It is not unusual to see more Lso-positive psyllids early in the season, but this level of Lso is higher than we typically see. It is fortunate that psyllid numbers are quite low, but the high prevalence of Lso suggests that we should be vigilant. We strongly urge growers to have their IPM programs in place. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

Please visit the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures and an archive of blog posts for this season: https://idahopestmonitoring.org/

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

» https://idahopestmonitoring.org/

First Lso-positive psyllid of the season

Potato All Locations

potato psyllid

Posted on: July 14, 2023 by Erik Wenninger

Apologies! This alert was posted on Friday, but an alert was not sent.

This week we received traps from all 55 fields that we are monitoring. We captured a total of 14 psyllids across 10 fields. Seven of the fields were in Canyon County; the remaining 3 fields were in Owyhee, Twin Falls, and Minidoka counties.

One of the psyllids we collected last week from Canyon County was positive for Lso, the bacterium associated with zebra chip disease (ZC). The other psyllids from last week were shipped to us late, so results are expected by Monday (and will be posted to the Idaho Pest Monitoring Dashboard, below). A positive psyllid this early in the season is somewhat concerning. ZC risk is in part a function of psyllid numbers and Lso incidence, so it is fortunate the psyllid numbers have been low so far. Nevertheless, we urge growers to watch psyllid captures closely and to have their IPM programs in place. More information on management can be found here: https://www.uidaho.edu/cals/potatoes/news/psyllid-management

Please visit our new site, the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures for this season and the previous three seasons: https://idahopestmonitoring.org/

We will be posting and archiving our weekly updates on this site. In addition to the graphical summaries, you will be able to look back on all the weekly “blog” summaries for this year and easily compare captures among counties, regions, and years over 2020 to 2023.

To view the weekly data by site in the old spreadsheet format: https://tinyurl.com/potatopsyllid

» https://idahopestmonitoring.org/

» https://www.uidaho.edu/cals/potatoes/news/psyllid-management

» https://tinyurl.com/potatopsyllid

2023 Miller Research Potato Pest Management Field Day

Potato All Locations

Posted on: July 11, 2023 by Jeff Miller

The 2023 Miller Research Potato Pest Management Field Day will be Wednesday, August 23 from 10:00 am to 12:15 pm with lunch to follow. More details are provided at the link and in the attached flier.

» https://millerresearch.com/event/2023-miller-research-potato-pest-management-field-day/

» 2023_MR_Field_Day_Announcement.pdf

2023 Potato psyllid monitoring program underway in Idaho

Potato All Locations

potato psyllid

Posted on: July 7, 2023 by Tasha Stanzak

The University of Idaho and our crop consultant collaborators across the state are once again monitoring for potato psyllids, zebra chip disease (ZC), and liberibacter (Lso), the bacterium associated with ZC. The monitoring program covers commercial potato fields throughout southern Idaho and is funded in part by the Idaho Potato Commission and generous in-kind contributions by our cooperators.

Our official monitoring season began with wide deployment of traps last week and will continue for 10 to 12 weeks. We have 55 fields across the state this year, using 4 sticky traps per field at all sites.

This week we received traps from 52 of the 55 fields that we are monitoring. We captured a total of four psyllids across three fields, all in Canyon County. In addition, a limited number of fields was monitored prior to the official start of the monitoring program. We captured one psyllid in a field in Canyon County last week and zero so far over four weeks of monitoring at the Kimberly Research & Extension Center.

It is still early, but thus far we are seeing relatively low numbers of psyllids, similar to the numbers we observed in 2022.

We expect to have results on Lso incidence next week.

Please visit our new site, the Idaho Pest Monitoring Dashboard, for graphical summaries of our psyllid captures for this season and the previous three seasons: https://idahopestmonitoring.org/

We will be posting and archiving our weekly updates on this site. So in addition to the graphical summaries, you will be able to look back on all the weekly “blog” summaries and easily compare this year’s captures to previous years.

» https://idahopestmonitoring.org/

Importance of scouting for late blight in potato

Potato Treasure Valley, Treasure Valley - Idaho, Magic Valley

Late blight (potato)

Posted on: June 21, 2023 by Brad Stokes

Importance of scouting for late blight in potato

Kasia Duellman, Jeff Miller, Nora Olsen, Mike Thornton, Phill Wharton and James Woodhall

It has been several years since we have had an outbreak of late blight in Idaho. It is easy to forget that late blight can be a threat in this region given all the other issues that growers have to deal with during the growing season. However, history tells us that the most widespread late blight outbreaks have been associated with two factors: 1) presence of volunteer potatoes from the previous crop and/or planting of seed potatoes sourced from regions where late blight frequently occurs, and 2) frequent rain events throughout the growing season.

We want to stress that late blight has not been found in Idaho so far this year. However, the unseasonably wet and moderate weather we’ve had recently has created conditions for potential late blight outbreaks in many locations. For example, in western Idaho where the crop is just closing the rows, we have had several weeks of intermittent showers as shown by records from the Parma Agrimet site.

Although many areas of Idaho experienced a colder than normal winter, higher snow falls across the Snake River Valley mean that the soil temperatures in many areas remained above freezing. The University of Idaho Volunteer Survival Model (https://cropalerts.org/volunteer-survival/), shows the risk of volunteer potato survival this year was high in most areas in southern Idaho. Infected volunteer potatoes, cull piles and seed tubers along with the recent wet weather conditions can all potentially contribute to the development of a late blight this year. As such, it would be prudent to plan ahead for the management of any potential late blight outbreaks.

Effective management of late blight requires the implementation of an integrated disease management approach, including strict sanitation practices (e.g. management of cull piles), good irrigation management, and the proper timing and application of effective fungicides. All these practices together can reduce the chances of a late blight outbreak.

Scouting is the first line of defense against late blight. Field scouting should begin after emergence when the first plants are 4 to 6 inches tall. In potato fields after plants close across the rows, look for late blight in the lower portions of the plant where the foliage stays wet longer. Scouting should be concentrated in areas of the field most likely to remain wet for the longest period of time, such as the center tower of pivot irrigation system, irrigation overlaps, and areas missed by fungicide applicators such as the edges of fields. Low spots where soil moisture is highest and parts of the field shaded by windbreaks are examples of areas where scouting should be intensified. The symptoms of late blight (see pictures at the end of this article) can be confused with other diseases and physiological disorders. If you find plants displaying symptoms of late blight, we recommend you take them to a local expert than can confirm the diagnosis.

Scouting allows growers to make informed disease and pest management decisions and provides early detection of other problems that may be present in the field, such as nutrient deficiency or herbicide injury. By using information collected by scouts, growers can time fungicide applications for optimal effectiveness. This is especially important for the control of late blight as fungicides are most effective when applied to foliage before infection occurs or when the disease is in its very earliest stages of development and no symptoms are visible. In the irrigated fields of southern Idaho, late blight can be very difficult to manage once infections become established as the humid microclimate within the canopy favors further disease development after irrigation.

There are a wide range of fungicides labeled for use against potato late blight. Each fungicide is different and will have specific conditions for use listed on the label with additional details regarding application rates, re-entry intervals and total product amounts that can be applied in a season. Some may even include information on how to minimize the risk of fungicide resistance developing. Fungicides that are effective for the control of late blight tend to have one of three modes of action: germination inhibition (they prevent germination of spores and thus plant infection), inhibiting mycelial growth (they block pathogen colonization of the plant cells), anti-sporulation activity (they prevent the pathogen from sporulating and thus limit spread of the disease). For more information on properties of fungicides registered for use in potatoes go to the following link: https://cropalerts.org/2020/04/24/potato-late-blight-control-recommendations-for-southern-idaho-in-2020/.

In years when late blight has been confirmed in Idaho it has usually appeared after mid-July. In the last wide scale outbreak that occurred in SE Idaho, late blight was first reported in Bingham County on July 10. On that date, the high temperature recorded at Aberdeen R&E Center was 67^oF and it had been a wet June with daily rainfall totals as high as 0.5 in. (see below). These are ideal disease conditions. If you suspect late blight please contact your local county UI Extension office or Kasia Duellman, Jeff Miller, Nora Olsen, Mike Thornton, Phill Wharton or James Woodhall.

A picture containing text, plot, screenshot, line 
 
Description automatically generated

To provide additional information on the threat of late blight the University of Idaho operates a spore trapping network in cooperation with the Idaho Potato Commission. Weekly updates from this network will be on the IPM website (https://idahopestmonitoring.org) starting the week of July 3^rd.

» Late blight foliar

» Late blight stem

» Late blight

Forecast is for cloddy with a chance of weeds

Potato All Locations

Weed control in cloddy fields

Posted on: May 18, 2023 by Pamela Hutchinson

All will agree that weather conditions spring 2023 have been
unusual: wide ranging snow cover, snow melt runoff and water pooling in fields,
and short bursts of intense wind and rain. One of the impacts on soil conditions
after potato growers were finally able to get into the fields for tillage and planting
has been the formation of clods.

What happens: Some preemergence herbicides applied
and sprinkler incorporated, or even chemigated, might not get below the clods,
resulting in patches of weeds emerging though the untreated soil.

What can be done: Questions have arisen about what
can be done proactively and the answer can be keeping herbicide solubility in
mind when designing a tank mixture. A more soluble herbicide might move through
and/or around ending up below clods resulting in better coverage. than a
herbicide with relatively less solubility.

What you need to know: In general, with the medium-
to coarse-textured, moderate organic matter content, neutral to high pH soils
in the PNW, potato herbicide solubility ranging from high to low: Matrix (rimsulfuron)
>> metribuzin, Outlook (dimethenamid-p) > Dual Magnum (s-metolachlor),
Eptam (EPTC) >> Linex (linuron), Reflex (fomesafen), Zidua
(pyroxasulfone) >> Chateau (flumioxazin), Sonalan (ethalfluralin),
Treflan (trifluralin), and Prowl H2O (pendimethalin). NOTE: Sulfentrazone
solubility is similar to that of Outlook unless soil pH is above 7.5, then it
is more soluble than the any of the other herbicides. Use of Trade Names is
not an endorsement for one product over another with the same active ingredient.

Put it together: Design a tank mixture for the weed
species in a field with inclusion of soluble herbicides that can move below the
clods for the best coverage possible.

Example: Control hairy nightshade, common
lambsquarters, and green foxtail in a cloddy field. Tank mix soluble Matrix or
Outlook for h. nightshade + soluble metribuzin for c. lambsquarters + moderately
soluble Linex for both** of the broadleaves. All provide green foxtail control.

Get out the crystal ball and the umbrella: If “unusual”
amounts of rainfall occur within 1 or 2 weeks after application and incorporation,
the “soluble” herbicides could move too far below the weed seed germination
zone.

Reference: Targeted Tank Mixtures for Weed Control in Potatoes – UI Extension
Bulletin 950 https://www.uidaho.edu/extension/publications/bul/bul950

**Keep in mind that tank mixing herbicides with different Sites
of Action (SOA) controlling the same weed species (“overlapping” control) is highly
recommended for herbicide resistance management. In the example given, Matrix, Outlook,
metribuzin, and Linex all have different SOAs. Without Linex, there is no
overlapping SOA for hairy nightshade and no overlapping SOA for common
lambsquarters. Linex as the third partner in the mix controls c. lambsquarters and has activity on h. nightshade. As a
result, there is more than one SOA on both weeds. The overlap is necessary for
herbicide resistance management. That one-in-a-million plant in the population naturally
tolerant to one SOA does not survive because the other SOA in the tank mixture will
provide control. If the tolerant plant survives and produces seeds because
overlapping herbicide SOA are not tank mixed and/or not rotated, then resistance
in the population could develop over time if only the one herbicide SOA is used.

Examples of Potato
Herbicide Sites of Action and weeds controlled - herbicides within [ ]
have the same SOA:

Hairy nightshade - Matrix, [Outlook/Dual Magnum/Zidua],
Eptam, [Reflex/Chateau], Linex;

Common lambsquarters – metribuzin, [Prowl H2O/Sonalan/Treflan],
Linex;

Redroot pigweed – all of these herbicides except metribuzin
when the population in a field is resistant to metribuzin;

Green foxtail – all of these herbicides.

When common lambsquarters is in a field with hairy nightshade,
then getting satisfactory SOA overlap is challenging. Linex seems to be the
only herbicide in that situation that can provide overlapping SOA for hairy
nightshade AND overlapping SOA for common lambsquarters.

» Solubility of herbicides labeled for use in potatoes

Miller Research Winter 2023 Potato Disease Management Seminar

Potato All Locations

Posted on: January 12, 2023 by Jeff Miller

Miller Research will be holding its annual Potato Pest
Management Meeting in person on February 16, 2023, at the Historic Wilson
Theater in Rupert, ID. The meeting will run from 9:00 am to 12:15 pm with a 15-minute
break at 10:30 am. CCA credits and ID, WA, and OR pesticide recertification
credits have been requested for the meeting.

For those not able to attend in person, a virtual option
will be available. If you want to participate by Zoom, contact Cheryn Suarez
(cheryn@millerresearch.com) after registration and she will
send you the link to attend. Virtual attendees will need to answer questions on
Zoom to verify participation. Thus, each person desiring credits needs to be
logged in and stay logged in for the duration of the meeting. Contact us if you
need to make other arrangements.

Registration is $20 to cover the cost of the meeting.
Additional proceeds will be donated to the local 4-H program.

The agenda is in the attached file.

» https://millerresearch.com/event/miller-research-winter-2023-potato-disease-management-seminar/

» 2023_Seminar_Announcement.pdf

final report of 2022 Idaho potato psyllid monitoring

Potato All Locations

potato psyllid

Posted on: September 16, 2022 by Erik Wenninger

This is the final report of the 2022 potato psyllid / Lso monitoring season.

The two psyllids captured last week tested negative for Lso, the bacterium associated with zebra chip disease (ZC).

It was an interesting year with very low psyllid captures overall, but relatively high incidence of Lso. About 22% of all psyllids tested positive for Lso compared to around 1% in most recent years. It is too soon to tell what this low psyllid / high Lso season means for ZC in tubers at harvest. Our studies in Russet Burbank showed that ZC can develop during storage if infection occurs as late as two weeks before vine kill. Please consider this in your late-season IPM programs. Risk could be mitigated by processing tubers from fields at higher risk sooner rather than later.

Thanks again to all of our cooperators!

With the monitoring season behind us, we urge you to kick the proverbial tires of our new Idaho Pest Monitoring site: https://idahopestmonitoring.org/

Please check it out and send us any feedback that we may use to improve the site. Our eventual goal is to make this a one-stop shop for all Idaho pest monitoring programs, but this is obviously still a work in progress.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

» https://idahopestmonitoring.org/

psyllid monitoring update - 1 Sep 2022

Potato All Locations

potato psyllid

Posted on: September 1, 2022 by Erik Wenninger

This week we received traps from 57 of the 72 fields that we are monitoring this year. Four fields have been vine killed and were not monitored. We found a total of only 5 psyllids across 5 (9%) of the 57 fields observed.

Psyllids were captured in the following counties: Canyon (2 fields), Elmore (1 field), and Twin Falls (2 fields).

None of the psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC).

Psyllid captures were especially low this week, and thankfully we’ve been seeing less and less Lso in recent weeks. With harvest season upon us, it is worth remembering that our studies in Russet Burbank showed that ZC can develop during storage if infection occurs as late as two weeks before vine kill. Please consider this in your late-season IPM programs. Risk could be mitigated by processing tubers from fields at higher risk sooner rather than later.

In addition to the regular links (below) with details on trap captures over the season, we are developing a new Idaho Pest Monitoring site that includes graphical summaries of our psyllid captures for this season and the previous two seasons: https://idahopestmonitoring.org/

Please click around on the Potato Psyllid / Zebra Chip Monitoring link and send us any feedback that we may use to improve the site. Our eventual goal is to make this a one-stop shop for all Idaho pest monitoring programs, but you can see that this is still a work in progress.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

» https://idahopestmonitoring.org/

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/

psyllid monitoring update, 26th Aug 2022

Potato All Locations

potato psyllid

Posted on: August 26, 2022 by Erik Wenninger

This week we received traps from 61 of the 72 fields that we are monitoring this year. Two fields have been vine killed and were not monitored; we are still waiting to receive traps from 9 fields in the Treasure Valley. We found a total of 16 psyllids across 10 (16%) of the 61 fields observed.

Psyllids were captured in the following counties: Canyon (2 fields), Gooding (1 field), Twin Falls (3 fields), Cassia (2 fields), and Minidoka (2 fields).

Two of the psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC). One was from a field in Canyon County and one from a field in Minidoka County.

We continue to see very low captures of psyllids relative to previous years and numbers are perhaps even lower this week than last week. However, we have also seen relatively high incidence of Lso, especially during previous weeks. With harvest season upon us, it is worth remembering that our studies in Russet Burbank showed that ZC can develop during storage if infection occurs as late as two weeks before vine kill. Please consider this in your late-season IPM programs. Risk could be mitigated by processing tuber from fields at higher risk sooner rather than later.

In addition to the regular links (below) with details on trap captures over the season, we are developing a new Idaho Pest Monitoring site that includes graphical summaries of our psyllid captures for this season and the previous two seasons: https://idahopestmonitoring.org/

Please click around on the Potato Psyllid / Zebra Chip Monitoring link and send us any feedback that we may use to improve the site. Our eventual goal is to make this a one-stop shop for all Idaho pest monitoring programs, but you can see that this is still a work in progress.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

» https://idahopestmonitoring.org/

» http://www.uidaho.edu/cals/potatoes/news

psyllid monitoring update, Aug 18, 2022

Potato All Locations

potato psyllid

Posted on: August 18, 2022 by Erik Wenninger

This week we received traps from 68 of the 72 fields that we are monitoring this year. We found a total of 35 psyllids across 18 (27%) of the 68 fields observed.

Psyllids were captured in the following counties: Canyon (4 fields), Payette (1 field), Gooding (1 field), Twin Falls (4 fields), Cassia (5 fields), and Minidoka (3 fields).

Thankfully, none of the psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC).

Psyllid captures are increasing as they always seem to do late in the season, though we continue to see very low captures of psyllids relative to previous years. However, we have also seen relatively high incidence of Lso during previous weeks. Most captures this week were from the eastern Magic Valley and western Treasure Valley, with no captures recorded this week from eastern Idaho. We urge growers to watch psyllid captures and Lso incidence closely and to have their IPM programs in place.

In addition to the regular links (below) with details on trap captures over the season, we are developing a new Idaho Pest Monitoring site that includes graphical summaries of our psyllid captures for this season and the previous two seasons: https://idahopestmonitoring.org/

Please click around on the Potato Psyllid / Zebra Chip Monitoring link and send us any feedback that we may use to improve the site. Our eventual goal is to make this a one-stop shop for all Idaho pest monitoring programs, but you can see that this is still a work in progress.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

Psyllid Captures

Potato All Locations

potato psyllid

Posted on: August 11, 2022 by Tasha Stanzak

This week we received traps from 70 of the 72 fields that we are monitoring this year. We found a total of 29 psyllids across 14 (20%) of the 70 fields observed.

Psyllids were captured in the following counties: Canyon (4 fields), Payette (1 field), Elmore (1 field), Jerome (1 field), Twin Falls (3 fields), Cassia (1 field), and Minidoka (3 fields).

Interestingly, 9 of the 18 psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC). Those positive psyllids were found in Canyon, Power, Cassia, and Twin Falls counties.

We continue to see low captures of psyllids this season, but relatively high incidence of Lso. We urge growers to watch psyllid captures and Lso incidence closely and to have their IPM programs in place.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

more Lso-positive psyllids found

Potato All Locations

potato psyllid

Posted on: August 4, 2022 by Erik Wenninger

This week we received traps from 68 of the 72 fields that we are monitoring this year. We found a total of 18 psyllids across 12 (18%) of the 68 fields observed.

Psyllids were captured in the following counties: Canyon (5 fields), Payette (1 field), Jerome (2 fields), Twin Falls (1 field), Cassia (1 field), Minidoka (1 field), and Power (1 field).

Interestingly, 14 of the 17 psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC). Positive psyllids were found in all counties in which we recorded psyllid captures last week.

We continue to see low captures of psyllids this season, but relatively high incidence of Lso. We urge growers to watch psyllid captures and Lso incidence closely and to have their IPM programs in place.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

» http://www.uidaho.edu/cals/potatoes/news

Psyllid Update July 28, 2022

Potato All Locations

potato psyllid

Posted on: July 29, 2022 by Tasha Stanzak

This week we received traps from 66 of the 72 fields that we are monitoring this year. We found a total of 17 psyllids across 11 (17%) of the 66 fields observed. Psyllids were captured from three fields in Canyon County on traps that had been deployed for two weeks.

Psyllids were captured in the following counties: Canyon (5 fields), Jerome (1 field), Twin Falls (3 fields), Cassia (1 field), and Minidoka (1 field).

Thankfully, none of the psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC).

Psyllid numbers this week ticked up a bit from last week’s very low count, but overall captures continue to lag far behind the total captures that we observed by this time last year.

Despite the low psyllid captures, given the incidence of Lso observed in previous weeks, we urge growers to watch psyllid captures closely and to have their IPM programs in place.

As promised last week, we can share one of the figure summaries of psyllid captures over the season compared among years. Visit our site, below, to see one such figure illustrating this year’s low captures relative to the last two years. We hope to be able to show you more in the coming weeks as we work out the “bugs” on our new psyllid monitoring page.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

Also, to view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

» psyllid_capture_comparison_by_week_2020_2021_to_26_july_2022.pdf

First Lso-positive psyllids of the 2022 season

Potato All Locations

potato psyllid

Posted on: July 15, 2022 by Erik Wenninger

This week we had traps deployed in 64 of the 72 fields that we are monitoring this year. We found a total of only 4 psyllids across 2 (3%) of the 64 fields.

Psyllids were captured in the following counties: Canyon (1 field) and Bingham (1 field).

5 of the 12 psyllids collected last week tested positive for Lso, the bacterium associated with zebra chip disease (ZC). Positive psyllids were collected from fields in Canyon, Owyhee, Twin Falls, and Cassia counties.

So far this has been a quiet season for psyllid captures in Idaho; by this time last year we were trapping well over 100 psyllids per week. However, the incidence of Lso observed last week is somewhat concerning. Risk of ZC is a function of both psyllid numbers and Lso incidence, so it is fortunate that psyllid numbers have been low thus far. In all of the fields in which a positive psyllid was found last week, no psyllids at all were found this week.

To view contour maps that illustrate relative psyllid abundance across the landscape, you can set up a free account here: https://potatoes.decisionaid.systems/ Updated maps will be generated every Friday morning.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the link under “Updated weekly reports” for details on trap captures.

--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

» http://www.uidaho.edu/cals/potatoes/news

2022 Potato psyllid monitoring program underway in Idaho

Potato All Locations

potato psyllid

Posted on: July 7, 2022 by Erik Wenninger

The University of Idaho and our crop consultant collaborators across the state are once again monitoring for potato psyllids, zebra chip disease (ZC), and liberibacter (Lso), the bacterium associated with ZC. The monitoring program covers commercial potato fields throughout southern Idaho and is funded in part by the Idaho Potato Commission and generous in-kind contributions by our cooperators.

Our official monitoring season began with wide deployment of traps last week and will continue for 10 to 12 weeks. We have 72 fields across the state this year, using 4 sticky traps per field at all sites.

This week we had traps deployed in 64 fields, though we are still waiting for traps to come in from three fields. We found a total of 12 psyllids across 7 (11%) of the fields for which we have data. We have been monitoring three fields at the Kimberly Research & Extension Center since mid-May, and, interestingly, this week is the first that we have found potato psyllids. In previous years we nearly always captured psyllids here before the end of May.

Psyllids were captured in the following counties: Canyon (3 fields), Owyhee (1 field), Twin Falls (2 fields), and Minidoka (1 field).

We expect to have results on Lso incidence next week in addition to “heat maps” and additional details.

More information on psyllid monitoring and management can be found here:

https://www.uidaho.edu/cals/potatoes/news/psyllid-management

Details on weekly trap captures can be found here:

https://docs.google.com/spreadsheets/d/1av-jeEKrbDfYis-eS9nB-ZcKzazXyMWmz7NSAiyt3Go/edit?usp=sharing

» https://www.uidaho.edu/cals/potatoes/news/psyllid-management

» https://docs.google.com/spreadsheets/d/1av-jeEKrbDfYis-eS9nB-ZcKzazXyMWmz7NSAiyt3Go/edit?usp=sharing

Growing Degree Days for Potatoes

Potato All Locations

Posted on: April 28, 2022 by Nora Olsen and Mike Thornton

Snow, hail,
rain, sunshine, and wind appear to be interchangeable this April. To focus on
the temperatures so far, calculating growing degree days (GDD) or heat units is
one method to look at the effect of temperature on the potato crop. Plant
growth and development is greatly influenced by temperature, and we use GDD to
get an idea of how the plant is developing throughout the season. It also gives
a great snapshot on how the current season compares to previous seasons. Daily
GDD is calculated by adding the maximum temperature and the minimum
temperature, dividing by 2 and subtracting a base temperature. The base
temperature is used to define the temperature at which potato growth is
diminished. <o:p></o:p>To quantify this
period of cold temperatures, we collated the cumulative GDDs for Parma,
Kimberly and Aberdeen. The source of the GDD was AgriMet (www.usbr.gov/pn/agrimet/wxdata.html)
weather stations located at the three sites. The AgriMet calculation of GDD
uses 50F as a minimum and 86F as a maximum. There are limitations to the use of
these minimum and maximums since potatoes will grow outside of this range, but
these calculations can still provide a reasonable prediction of the temperatures
impacting potato growth. The GDD these past weeks is quite a contrast to the
GDD from 2021 and the 11-year average.<o:p></o:p>

To help
provide a picture of the relationship between temperature and plant
development, we will continue to update the GDD graphs weekly for the three
locations and post at <a href="http://www.uidaho.edu/cals/potatoes/storage">www.uidaho.edu/cals/potatoes/storage</a>. Aberdeen GDD was not available at
this time but will be posted on the website when available.<o:p></o:p>

» http://www.uidaho.edu/cals/potatoes/storage

Seeking help for a research project

Potato All Locations

Posted on: April 7, 2022 by Jeff Miller

A research project funded by the tri-state (ID, WA, and OR) research consortium is looking for some help (see below). If you are able and interested, please contact David Wheeler (contact info below).

Good luck with planting!

Jeff

A team of scientists at Washington State University, Oregon State University and USDA-ARS received a second year of funding from the Northwest Potato Research Consortium to characterize so called “virgin” soils that have never been planted with potato. Growers have long observed yield increases (14-26%) when planting potato in virgin soils compared to nearby non-virgin soils that have been planted in potato. Our short term goal is to document the properties (e.g. biological, physical, and chemical) in the soil associated with these yield increases. Long term we want to use this information to reproduce these yield increases in commercial fields. To do this we need your help!

Can you please reach out to us if you know any pairs of potato fields that will be planted with potato this year and were either (i) planted with potatoes within the past 5 years (non-virgin fields) or (ii) never planted with potato (virgin fields)? With your permission we can then visit each field, sample soil from each field before planting, and sample soil from nearby “native soil” that has never been planted with any crop. Once we have these three types of samples we will characterize the soil pathogen loads, nematode diversity and abundance, and soil biological, physical, and chemical properties. Lastly, we will bring the soils to a common location and plant potatoes in each soil to quantify potato performance in each soil type.

Please contact David Wheeler via email (David.wheeler@wsu.edu) or mobile (215-880-3024). Thank you all in advance for your time and attention. We look forward to working together this year.

David Wheeler, Cynthia Gleason, Ken Frost, Deirdre Griffin LaHue, and Tim Paulitz

Potato soil health survey - your help is requested!

Potato All Locations

Posted on: February 18, 2022 by Jeff Miller

Researchers from the University of Idaho, Montana State University, and the University of Minnesota would like your feedback on potato production and soil health. The results of this survey will influence the important research done by these teams. They'll ask questions about crop rotations, soil health management practices, and fumigation in this brief survey. As a token of their appreciation, you'll be eligible to enter into a drawing for a $100 Cabela's (or equivalent) gift card after you've completed the survey. If you have any questions, please contact Alex Maas at alexmaas@uidaho.edu.

Click Here to Begin Survey

» https://uidaho.co1.qualtrics.com/jfe/form/SV_8bQye9iBZ5UHI0K

2022 Miller Research Potato Pest Management Meeting Final Notice

Potato All Locations

Posted on: January 31, 2022 by Jeff Miller

Miller Research will be holding its annual Potato Pest Management Meeting in person on February 10, 2022, at the Historic Wilson Theater in Rupert, ID. The meeting will run from 8:30 am to 12:00 pm with a 30-minute break at 10:00 am. Three credits have been awarded for CCA (integrated pest management), Idaho, Oregon, and Washington pesticide recertification.

For those not able to attend in person, a virtual option will be available. If you want to participate by Zoom, contact Cheryn Suarez (cheryn@millerresearch.com) after registration and she will send you the link to attend. Virtual attendees will need to answer questions on Zoom to verify participation. Thus, each person desiring credits needs to be logged in. Contact us if you need to make other arrangements.

Registration is $20 to cover the cost of the meeting. After covering meeting costs, additional proceeds will be donated to the 4-H program.

Meeting agenda:

8:00 am – 8:30 am: Registration

8:30 am – 9:00 am: Seed treatments for Fusarium dry rot management

9:00 am – 9:30 am: The impact of anastomosis group on Rhizoctonia canker management

9:30 am – 10:00 am: Verticillium wilt control

10:00 am – 10:30 am: Break

10:30 am – 11:00 am: Control options for powdery scab and potato mop-top virus

11:00 am – 11:30 am: PVY and Seed Health (Dr. Jonathan Whitworth, USDA)

11:30 am – 12:00 pm: Managing pesticide resistance

» https://millerresearch.com/event/2022-miller-research-potato-pest-management-meeting/

» 2022_Seminar_Announcement.pdf

Idaho Potato Conference

Potato All Locations

Posted on: January 13, 2022 by Nora Olsen and Mike Thornton

Early
registration ends tomorrow Friday January 14^th. Register Now!

The 54^th
annual Idaho Potato Conference and Eastern Idaho Ag Expo presented by the
University of Idaho and Spectra Productions will be live and in-person in 2022.
Set your calendars to attend the 2022 Idaho Potato Conference January 19 and 20
in Pocatello, ID. Attend your choice of educational presentations and workshops
from three concurrent sessions over the one and half-day conference and take
some time to visit the adjoining trade show that features over 70 booths and
displays highlighting agricultural products and services.

2022 highlights of the Idaho Potato
Conference:

· There
will be several seminars and workshops on the impact of the 2021 season
including heat impact on potatoes, soil health, storage losses, and irrigation
efficiency.

· Invited
speaker Dr. Carrie Wohleb from Washington State University will present on the Impacts
of Wildfire Smoke on Potatoes.

· Current
outlooks on water, economics, labor and sustainability from industry leaders
will bring us up to date on major topics for the potato industry.

· Special
guests from the National Potato Council, Potatoes USA, Idaho Potato Commission
will provide industry updates.

· Multiple
pest protection presentations and workshops including tank mixing
considerations, rotational crops and herbicide carryover issues, pollinators
and potatoes, Fusarium dry rot aggressiveness, managing Rhizoctonia, diagnosing
crop injury, pesticide resistance management, alternatives to fumigation,
rotation and potato cyst nematode control, and comprehensive disease and weed
management workshops.

· Economists
will present a workshop on the profitability implications of fertilizer cost
increases in addition to a discussion on the seasonality of retail rejections.
The latter discussion will dovetail with a one-hour workshop on the impact of
bruise on quality.

· A
workshop dedicated to ‘Everything you wanted to know about potato viruses, but
were afraid to ask.’ Come with questions to ask a panel of experts on the topic
of tuber necrotic diseases.

· Seminars
and workshops in Spanish will be held both days and include a wide variety of
topics from beneficial insect identification to farm safety discussions.

· Earn
CCA (CEU) and pesticide recertification credits at seminars and workshops
throughout the in-person conference.

· Select
theater presentations will be recorded and available at the conference website
after the conference. Registration for the conference will be required to gain
access to the recorded presentations.

·
Cost for
pre-registration is $40 per person. Pre-registration will close at 5 pm MT on
January 14. After that time, please plan to register in-person at the
conference (cost increase to $50). We strongly encourage everyone to
pre-register and avoid the lines at the conference. Additional details
regarding the agenda, topics, and registration can be found at https://www.uidaho.edu/cals/potatoes/news/idaho-potato-conference.

» https://www.uidaho.edu/cals/potatoes/news/idaho-potato-conference.

2022 Idaho Potato Conference

Potato All Locations

Posted on: January 6, 2022 by Nora Olsen and Mike Thornton

Register
Now!

The 54^th
annual Idaho Potato Conference and Eastern Idaho Ag Expo presented by the
University of Idaho and Spectra Productions will be live and in-person in 2022.
Set your calendars to attend the 2022 Idaho Potato Conference January 19 and 20
in Pocatello, ID. Attend your choice of educational presentations and workshops
from three concurrent sessions over the one and half-day conference and take
some time to visit the adjoining trade show that features over 70 booths and
displays highlighting agricultural products and services.

2022 highlights of the Idaho Potato
Conference:

· There
will be several seminars and workshops on the impact of the 2021 season
including effect of the weather on soil fertility, heat impact on potatoes,
soil health, storage losses, and irrigation efficiency.

· Invited
speaker Dr. Carrie Wohleb from Washington State University will present on the Impacts
of Wildfire Smoke on Potatoes.

· Current
outlooks on water, economics, labor and sustainability from industry leaders
will bring us up to date on major topics for the potato industry.

· Special
guests from the National Potato Council, Potatoes USA, Idaho Potato Commission
will provide industry updates.

· Multiple
pest protection presentations and workshops including tank mixing
considerations, rotational crops and herbicide carryover issues, pollinators
and potatoes, Fusarium dry rot aggressiveness, managing Rhizoctonia, diagnosing
crop injury, pesticide resistance management, alternatives to fumigation, rotation
and potato cyst nematode control, and comprehensive disease and weed management
workshops.

·
Economists will present a workshop on
the profitability implications of fertilizer cost increases in addition to a
discussion on the seasonality of retail rejections. The latter discussion will
dovetail with a one-hour workshop on the impact of bruise on quality.

·
A workshop dedicated to ‘Everything
you wanted to know about potato viruses, but were afraid to ask.’ Come with
questions to ask a panel of experts on the topic of tuber necrotic diseases.

·
Seminars and workshops in Spanish will
be held both days and include a wide variety of topics from beneficial insect
identification to farm safety discussions.

Earn CCA (CEU) and pesticide
recertification credits at seminars and workshops throughout the in-person
conference.

Select presentations will be recorded
and available at the conference website after the conference. Registration for the
conference will be required to gain access to the recorded presentations.

Cost for pre-registration is $40 per person ($50 at the
door). We strongly encourage everyone to pre-register and avoid the lines at
the conference. Additional details regarding the agenda, topics, and
registration can be found at https://www.uidaho.edu/cals/potatoes/news/idaho-potato-conference.

» https://www.uidaho.edu/cals/potatoes/news/idaho-potato-conference

2022 Miller Research Potato Pest Management Meeting

Potato All Locations

Posted on: December 17, 2021 by Jeff Miller

After meeting virtually in 2021, Miller Research will be
holding its annual Potato Pest Management Meeting in person on February 10,
2022, at the Historic Wilson Theater in Rupert, ID. The meeting will run from
8:30 am to 12:00 pm with a 30-minute break at 10:00 am. Three CCA (integrated
pest management) credits and three ISDA pesticide recertification credits have
been awarded for the meeting. Oregon and Washington credits have been requested.

We are working on making a virtual option available. If this
works, virtual attendees will still need to pay the registration fee and answer
questions during the presentation as proof of attendance.

Registration is $20 to cover the cost of the meeting.
Additional proceeds will be donated to the 4-H program.

Meeting agenda:

8:00 am – 8:30 am: Registration

8:30 am – 9:00 am: Seed treatments for Fusarium dry rot
management

9:00 am – 9:30 am: The impact of anastomosis group on
Rhizoctonia canker management

9:30 am – 10:00 am: Verticillium wilt control

10:00 am – 10:30 am: Break

10:30 am – 11:00 am: Control options for powdery scab and
potato mop-top virus

11:00 am – 11:30 am: PVY and Seed Health (Dr. Jonathan
Whitworth, USDA)

11:30 am – 12:00 pm: Managing pesticide resistance

» https://millerresearch.com/event/2022-miller-research-potato-pest-management-meeting/

» 2022_MR_Seminar_Announcement.pdf

Register for the in-person 2022 Idaho Potato Conference

Potato All Locations

Posted on: November 29, 2021 by Nora Olsen and Mike Thornton

Registration
is now OPEN!

The 54^th
annual Idaho Potato Conference and Eastern Idaho Ag Expo presented by the
University of Idaho and Spectra Productions will be live and in-person in 2022.
Set your calendars to attend the 2022 Idaho Potato Conference January 19 and 20
in Pocatello, ID. Attend your choice of educational presentations and workshops
from three concurrent sessions over the one and half-day conference and take
some time to visit the adjoining trade show that features over 70 booths and
displays highlighting agricultural products and services.

Seminars and workshops in Spanish will
be held both days and include a wide variety of topics from beneficial insect
identification to farm safety discussions.

Earn CCA (CEU) and pesticide
recertification credits at seminars and workshops throughout the in-person
conference.

Select presentations will be recorded
and available at the conference website after the conference. Registration for the
conference will be required to gain access to the recorded presentations.

Potato All Locations

Potato Psyllid

Posted on: July 29, 2021 by Lucy Standley

This week we
had traps deployed in all 73 fields monitored this year. We found a total of 126
psyllids across 36 (49%) of the 73 fields.

Psyllids were
collected on sticky traps in potato in the following counties: Canyon (11
fields), Owyhee (2 fields), Elmore (2 fields), Payette (1 field), Gem (1
field), Gooding (2 fields), Jerome (4 fields), Twin Falls (6 fields), Cassia (2
fields), Minidoka (3 field), and Power (2 fields).

Psyllid
captures overall declined a bit from last week. Contour maps (see links below)
still graphically reflect relatively high abundance of psyllids collected in
some fields in the western Treasure Valley and Elmore County, but both areas
show more moderate incidence of psyllids than last week. Moderate captures were
recorded in the Magic Valley, and we continue to see very few psyllids in the
Upper Snake region.

All of the
psyllids tested from previous weeks have been negative for Lso. Samples tested
from last week so far show no evidence of Lso; however, we only have results
from one of the two primers used to test for Lso. Results from the first primer
were all negative, which was sufficient to confirm a negative result in almost all
of our tests during that past ten years. We should have results from the second
primer tomorrow to confirm these results, and we will post another update if
any samples are positive.

We urge growers
to watch psyllid numbers closely during the coming weeks and to have their IPM
programs in place.

Contour maps or
“heat maps” are included on the UI website (see link below). These maps
describe predicted psyllid densities across the landscape, based on our trap
counts and on predictive models developed in collaboration with colleagues at
Washington State University from our many years of data on psyllids in Idaho.
We include just a screenshot of the contour maps on our site, so we encourage
stakeholders to visit the Decision Aid Systems site and create a free account
to view each week’s maps and other pest data in more detail: https://potatoes.decisionaid.systems/

More information
can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the
links under “Updated weekly reports” for details on trap captures.

--Click on the
“Psyllid Management” link on the left panel for information on psyllid and
zebra chip biology and management.

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/

Psyllid Update July 22, 2021

Potato All Locations

Potato Psyllid

Posted on: July 22, 2021 by Lucy Standley

This week we
had traps deployed in all 73 fields monitored this year. We found a total of
191 psyllids across 31 (42%) of the 73 fields.

Psyllids were
collected on sticky traps in potato in the following counties: Canyon (11
fields), Owyhee (3 fields), Elmore (2 fields), Payette (1 field), Gem (1
field), Gooding (1 field), Jerome (3 fields), Twin Falls (7 fields), Minidoka
(1 field), and Power (1 field).

All of the
psyllids tested from previous weeks have been negative for Lso, though we are
waiting for results from 32 psyllids from six fields that arrived to us late.
We continue to have issues with shipping times being slower than in previous
years.

Psyllid
captures overall ticked up slightly from last week. Contour maps (see links
below) graphically reflect the relatively high abundance of psyllids collected
in some fields in the western Treasure Valley during the past three weeks, as
well as a “hot spot” that has been growing each week in Elmore County. A small
area west of Twin Falls showed relatively high captures this week as well. Very
few psyllids have been detected in the Upper Snake region thus far.

We urge growers
to watch psyllid numbers closely during the coming weeks and to have their IPM
programs in place.

Contour maps or
“heat maps” are included on the UI website (see link below). These maps
describe predicted psyllid densities across the landscape, based on our trap
counts and on predictive models developed in collaboration with colleagues at
Washington State University from our many years of data on psyllids in Idaho. We
include just a screenshot of the contour maps on our site, so we encourage
stakeholders to visit the Decision Aid Systems site and create a free account
to view each week’s maps and other pest data in more detail: https://potatoes.decisionaid.systems/

More information
can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the
links under “Updated weekly reports” for details on trap captures.

--Click on the
“Psyllid Management” link on the left panel for information on psyllid and
zebra chip biology and management.

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/

2021 Miller Research Potato Pest Management Field Day

Potato All Locations

Posted on: July 20, 2021 by Jeff Miller

Miller Research will be holding its annual potato pest
management field day on Thursday, August 19. The event is open to the public
and there is no cost to attend but
please RSVP so we can plan appropriately for the event. This can be
done on our website or by responding to jeff@millerresearch.com or (208)
431-4420. More details can be found by following the attached link.

» https://millerresearch.com/event/2021-miller-research-potato-pest-management-field-day/

» 2021-MR-Field-Day-Announcement.pdf

Psyllid Update July 15, 2021

Potato All Locations

potato psyllid

Posted on: July 15, 2021 by Erik Wenninger

This week we
had traps deployed in all 76 fields monitored this year (though we are waiting
to receive traps from 11 sites). We found a total of 76 psyllids across 18 (28%)
of the 65 fields for which we have data. Several of the fields for which we are
waiting for traps are from fields in and near Canyon County in which we found relatively
high numbers of psyllids last week, thus we would expect these figures to tick
up when these data are added.

Psyllids were
collected on sticky traps in potato in the following counties: Canyon (6
fields), Owyhee (2 fields), Elmore (2 fields), Gooding (1 field), Jerome (2
fields), Twin Falls (5 fields), and Bingham (1 field).

All of the
psyllids tested from previous weeks have been negative for Lso, though we are
waiting for results from two individual psyllids from two fields from last week
(the other psyllids tested from those fields were negative).

Psyllid
captures overall are similar to last week. We urge growers to watch psyllid
numbers closely during the coming weeks and to have their IPM programs in place.

Contour maps or
“heat maps” of this week’s and the previous week’s results are included on the
UI website (see link below). These maps describe predicted psyllid densities
across the landscape, based on our trap counts and on predictive models developed
in collaboration with colleagues at Washington State University from our many
years of data on psyllids in Idaho. The maps graphically reflect the relatively
high abundance of psyllids collected in some fields in the western Treasure
Valley during the past two weeks, as well as a “hot spot” in Elmore County.
Abundance of psyllids remains moderate to low in the Magic Valley and very few
psyllids have been detected in the Upper Snake region.

We include just
a screenshot of the contour maps on our site, so we encourage stakeholders to
visit the Decision Aid Systems site and create a free account to view these and
other data in more detail: https://potatoes.decisionaid.systems/

More information
can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the
links under “Updated weekly reports” for details on trap captures.

--Click on the
“Psyllid Management” link on the left panel for information on psyllid and
zebra chip biology and management.

Psyllid Update July 8, 2021

Potato All Locations

Potato Psyllid

Posted on: July 8, 2021 by Lucy Standley

This week we
had traps deployed in 73 of the 76 fields (96%) monitored this year and we
found a total of 139 psyllids across 30 (41%) of the 73 fields. We are waiting
to receive cards from 9 more sites.

Psyllids were
collected on sticky traps in potato in the following counties: Payette (1
field), Canyon (12 fields), Gem (1 field), Owyhee (3 fields), Elmore (2
fields), Gooding (1 field), Jerome (2 fields), Twin Falls (5 fields), Minidoka
(2 fields), and Power (1 field).

Lso results are
still pending due to shipping delays, but results will be posted on our site
(below) once results are in.

Thus far,
psyllid captures are tending to be a bit higher than they were at this time the
last two years. We urge growers to watch psyllid numbers closely during the
coming weeks and to have their IPM programs in place.

More information
can be found here: http://www.uidaho.edu/cals/potatoes/news

--Click on the
links under “Updated weekly reports” for details on trap captures.

--Click on the
“Psyllid Management” link on the left panel for information on psyllid and
zebra chip biology and management.

» http://www.uidaho.edu/cals/potatoes/news

2021 Potato psyllid monitoring program in Idaho

Potato All Locations

potato psyllid

Posted on: July 2, 2021 by Erik Wenninger

The University
of Idaho and our crop consultant collaborators across the state are once again monitoring
for potato psyllids, zebra chip disease (ZC), and liberibacter (Lso), the
bacterium associated with ZC. The monitoring program covers commercial potato
fields throughout southern Idaho and is funded in part by the Idaho Potato
Commission and generous in-kind contributions by our cooperators.

Our official monitoring
season began with wide deployment of traps this week and will continue for 10
to 12 weeks. We should have about 76 fields across the state this year, using 4
sticky traps per field at all sites.

In early to mid-June
we began monitoring in three fields at the Kimberly R&E Center (KREC) and in
eight commercial fields in the Treasure Valley (mostly in Canyon County). On
traps retrieved during the weeks of June 14, 21, and 28, we captured a total of
1, 4, and 8 potato psyllids, respectively, among our fields at KREC. Among seven
of the eight fields in the Treasure Valley, we captured an average of about 2
psyllids per field during each of the last two weeks; however, in one Canyon
County field, we captured 19 psyllids this week.

Potato All Locations

Posted on: August 10, 2020 by Nora Olsen

Potato harvest is upon us in Idaho and new on-line resources are available at the University of Idaho to help in bruise and quality management. Written and video resources can be found at www.uidaho.edu/cals/potatoes/bruise-management.
A new bulletin on ‘Monitoring tools for a potato bruise prevention program’ is now posted. This bulletin highlights tools or methods to quickly identify where in harvest and handling operation potatoes may experience physical impacts that cause blackspot and shatter bruises. The bulletin outlines a relatively simple and quick way to detect shatter bruises with the use of an iodine solution. The coloration of the shatter bruises makes it easy to determine the number and severity of the bruises. Although blackspots bruises take time to develop, recent research on Russet Burbank, Ranger Russet and Russet Norkotah indicates the ability to see a majority of the bruises within 3-5 hours after harvest. Peeling potatoes to identify early blackspot bruise symptoms is a useful monitoring tool that can help pinpoint equipment that needs to be adjusted. Another option is to run an instrumented sphere though your operation to measure the acceleration of an impact. The shape and size of the instrumented sphere mimics a potato, making it very useful tool to help identify handling equipment that may be at higher risk for bruising. Monitoring shatter and blackspot bruise levels during harvest and handling operations with the tools outlined in this bulletin provides opportunities to modify equipment and conditions; and also to identify lots or fields that have a greater degree of bruise. Training videos are also available on the website. These 3-minutes videos highlight how to run and operate equipment associated with harvest and handling of potatoes in order to prevent bruising and maximize crop quality. Available videos include:
- Windrower operation (English and Spanish)
- Harvester operation (English and Spanish)
- Moving potatoes from truck to piler (English)
- Best practices for piling potatoes (English and Spanish)
- Unloading potatoes out of storage (English)

Another Lso-positive psyllid

Potato All Locations

Potato Psyllid

Posted on: July 30, 2020 by Lucy Standley

This week we had traps deployed in 65 of the 65 fields (100%) monitored this year; we found a total of 114 psyllids across 28 (43%) of the 65 fields.

Psyllids were collected on sticky traps in potato in the following counties: Payette (1 field), Canyon (10 fields), Owyhee (1 field), Gem (2 fields), Elmore (2 fields), Gooding (1 field), Jerome (2 fields), Twin Falls (7 fields), Minidoka (1 fields), and Power (1 field).

From last week’s samples, one psyllid (collected in Twin Falls County) tested positive for Lso (liberibacter), the bacterium associated with zebra chip disease (ZC). This is the second observation of an Lso-positive psyllid in our monitoring program in as many weeks. Overall incidence of Lso still remains relatively low (about 1% through last week).

“Heat maps” of this week’s results are included on the UI and WSU websites (see links below). “Heat maps” describe predicted psyllid densities across the landscape, based on our trap counts and on predictive models developed over six years of psyllid monitoring in Idaho. The heat maps graphically reflect the relatively high abundance of psyllids collected in the Western Treasure Valley.

Psyllid captures were higher this week, though similar to total captures during late July to early August last year. Given this increase and the additional observation of an Lso-positive psyllid, we continue to urge growers to have their IPM programs in place.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news
--Click on the links under “Updated weekly reports” for details on trap captures.
--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/idaho

» July30EastMap

» July30WestMap

First Lso-positive psyllids in 2020 Idaho monitoring

Potato All Locations

Potato Psyllid

Posted on: July 23, 2020 by Lucy Standley

This week we had traps deployed in 59 of the 65 fields (91%) monitored this year (though we have not yet received traps from 6 of these fields); we found a total of 83 psyllids across 28 (53%) of the 53 fields with data.

Psyllids were collected on sticky traps in potato in the following counties: Canyon (12 fields), Owyhee (2 fields), Gem (2 fields), Elmore (3 fields), Jerome (1 field), Twin Falls (7 fields), Minidoka (2 fields), and Oneida (1 field).

From last week’s samples, two psyllids tested positive for Lso (liberibacter), the bacterium associated with zebra chip disease (ZC). These hot psyllids were collected from two different fields: one in Twin Falls and one in Jerome County. This is the first observation of Lso-positive psyllids in our monitoring program this year. This is about one week and two weeks later than the first observation of Lso-positive psyllids during 2019 and 2018, respectively.

“Heat maps” of this week’s results are included on the UI and WSU websites (see links below). “Heat maps” describe predicted psyllid densities across the landscape, based on our trap counts and on predictive models developed over six years of psyllid monitoring in Idaho. These maps, developed in collaboration with WSU, should be used as a guideline, but not a definitive count of the number of insects in any given field at any given point in time. “Low,” “Moderate,” “High,” and “Very High” designations are arbitrary categories that illustrate relative abundance and should not be used as “thresholds.” More details on the “heat maps” can be found in Potato Progress Volume XVII, Number 2, 15 February 2017.

Psyllid captures were a bit higher this week, though similar to total captures during late July to early August last year. Given this increase and the first observation this year of Lso-positive psyllids in Idaho, we urge growers to have their IPM programs in place.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news
--Click on the links under “Updated weekly reports” for details on trap captures.
--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/idaho

» July23WestMap

» July23EastMap

Potato All Locations

Posted on: June 29, 2020 by Nora Olsen and Mike Thornton

As part of the Idaho Potato Commission-funded quality project we have been working with one of the largest retailers of potatoes to monitor the incidence of defects seen at the consumer level in the 2017, 2018 and 2019 potato crops. The good news is that we have seen an improvement in the quality of potatoes delivered over the three years of the project. We believe that this improvement in quality is due in large part to the emphasis on reducing bruise damage being exhibited at both the grower and shipper levels.
One of the best ways to reduce bruise damage is to focus on training the people that operate every piece of potato handling equipment on their role in the effort to improve quality. To that end, we have developed several training resources on our website under the “Bruise Management” tab. In 2019 we focused on videos that show windrower and harvester operators the key factors in operating that equipment in a way that minimizes bruise. But we realize that bruising can take place any time potatoes are handled, so in 2020 we focused on the equipment that moves potatoes from the truck into storage, the piling operation, and the process of removing the potatoes from storage. The result is three new videos entitled Moving Potatoes from Truck to Piler, Best Practices for Piling Potatoes, and Unloading Potatoes Out of Storage. Each video is only 3 to 4 minutes long, but cover the basic operating principles and show several viewpoints so that equipment operators can see what the machinery should look like when operating properly.
Special thanks go to Jason Thomas (Minidoka County Extension Educator) for the narration, and Bill Schaefer for shooting the video and editing it all into the final product.
The initial videos are available in English. However, we anticipate that a Spanish version of the videos will be posted shortly. All these videos are available at the following website:
https://www.uidaho.edu/cals/potatoes/bruise-management/training-videos

Volunteer potato control recommendations for 2020

Potato All Locations

Idaho Potato Conference January 22-23, 2020

Potato All Locations

Posted on: November 22, 2019 by Nora Olsen

Please mark your calendars for the 52nd annual Idaho Potato Conference and Trade Show presented by the University of Idaho and Spectra Productions to be held in Pocatello, Idaho January 22-23, 2020. Additional details and registration can be found at https://www.uidaho.edu/cals/potatoes/news/idaho-potato-conference
Highlights for this year’s conference include:
- Several seminars and workshops on the impact of the 2019 season including effect of spring rain on weed control, late season bulking and maturity, cold harvest weather and quality, and late season irrigation, disease and weed management.
- Invited speaker Dr. Sastry Jayanty from Colorado State University will present a seminar on How to minimize pressure bruise in long-term storages and a workshop on managing shrinkage in storage. Come listen to these presentations on Wednesday January 22.
- Invited speaker Dr. Carl Rosen from the University of Minnesota will address soil health and crop nutrient management. These presentations are part of a special session with dedicated seminars and workshops specifically focused on soil and crop health on Thursday January 23.
- Variety management and performance of new varieties, irrigation system efficiency, virus, minor insect pests, late blight and other diseases, how potatoes are graded, and much more will be discussed on Wednesday. Including a special panel discussion of industry issues by the Idaho Potato Commission, National Potato Council, and Potatoes USA.
- Optimizing fumigation, soilborne and seedborne diseases, pesticide drift and misapplication, and much more will be presented on Thursday January 23.
- Seminars and workshops in Spanish will be held both days and include a wide variety of topics from farm safety to disease and disorder identification.
- CCA and pesticide recertification credits will be available.
- New this year: a technical room dedicated to learning how various pieces of equipment or technology work. This year will include multiple storage panels, agronomic software and harvest equipment.
- New this year: Come enjoy a free baked potato bar at lunch on Wednesday January 22!

» https://www.uidaho.edu/cals/potatoes/news/idaho-potato-conference

Updated manual and resources now available to help navigate the 2019 Potato Sustainability Initiative (PSI) survey

Potato All Locations

Potato Sustainability Initiative Survey

Posted on: October 25, 2019 by Nora Olsen

Updated manual and resources now available to help navigate the
2019 Potato Sustainability Initiative (PSI) survey

Potato growers—you will soon be asked to answer the annual Potato Sustainability Initiative (PSI) survey. Most process, and some fresh, growers are requested to participate in the PSI sustainability survey. Please note: there will be no audit for the 2019 survey.
In the past, approximately 20% of the growers who completed the survey were audited each year. The audit involved an interview between the grower and auditor with specific questions and an inspection of documents. A manual was developed to help growers methodically and successfully gather required documents for the audit, with examples of standard operating procedures, and resources to help answer interview questions. Audit information was retained in the manual as a reference and resource for future audits.
The manual is posted at https://www.uidaho.edu/cals/potatoes/food-and-farm-safety
The 2019 survey changed slightly from the 2018 survey.
The manual was developed by University of Idaho, Washington State University and IACI with funding from the NW Potato Research Consortium.

Call for Pink Rot

Potato All Locations

Pink Rot (Phytophthora erythroseptica)

Posted on: September 6, 2019 by Jeff Miller

Miller Research has received funding to evaluate the pink rot pathogen (Phytophthora erythroseptica) for sensitivity to mefenoxam and phosphorous acid. If you observe pink rot, please send us samples. It is best to send tubers which are only partially decayed and still have some healthy tissue remaining. It is very difficult, if not impossible, to isolate the organism from completely rotted tubers.

Wrap tubers in dry paper towels and send them as quickly as possible to:
Miller Research
426 E 200 N
Rupert, ID 83350

Please contact Cheryn Clayton by phone (208-531-5124) or email (cheryn@millerresearch.com) to notify us that samples are being sent. If you have any questions, please feel free to contact me at 208-431-4420.

Good luck with harvest!

Jeff Miller

Psyllid update September 5 2019

Potato All Locations

Potato Psyllid

Posted on: September 5, 2019 by Lucy Standley

This week we had traps deployed in 62 of the 79 fields (78.4%) monitored this year, and we found a total of 32 psyllids across 13 (16.4%) of the 79 monitored fields. Many of the 79 total fields that we were sampling have been vine-killed.

Psyllids were collected on sticky traps in potato in the following counties: Payette (1 field), Canyon (6 fields), Owyhee (2 fields), Twin Falls (2 fields), Jerome (1 field), and Power (1 field).

All psyllids collected last week tested negative for Lso (liberibacter), the bacterium that causes zebra chip.

Our research with Russet Burbank in Idaho has shown that plants should be protected from infection with the ZC bacterium at least until one week before vine kill to reduce ZC symptoms. Therefore, we continue to urge growers to maintain their IPM programs.

We are not including “heat maps” this week given that they tend to show skewed patterns with smaller sample sizes.

Following recommendations from our ZC Advisory Committee last year, we shortened the duration of our monitoring program. This week we conclude the official monitoring program, though we will continue monitoring fields at the Kimberly Research & Extension Center as well as grower- and crop consultant-submitted samples. We will post any important updates that develop.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news
--Click on the links under “Updated weekly reports” for details on trap captures.
--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.
--WSU site: https://potatoes.decisionaid.systems/idaho

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/idaho

2019 Vine Kill Recommendations - Late Blight infected and non-infected fields

Potato All Locations

Vine Kill

Posted on: August 30, 2019 by Pamela Hutchinson

Information about vine kill with little or no mechanical operations (beating/flailing, splitting vines). Late blight spores can spread by mechanical vine kill. Use of only vine-kill chemical products can provide enough reduction of plant material for efficient harvest.

Psyllid abundance remains relatively steady

Potato All Locations

potato psyllid

Posted on: August 29, 2019 by Erik Wenninger

This week we had traps deployed in 76 of the 79 fields (96.2%) monitored this year, and we found a total of 58 psyllids across 26 (32.9%) of the 79 monitored fields. Three of the 79 total fields that we were sampling have been vine-killed.

Psyllids were collected on sticky traps in potato in the following counties: Payette (3 fields), Canyon (10 fields), Elmore (4 fields), Twin Falls (4 fields), Jerome (2 fields), and Cassia (3 fields).

All psyllids collected last week tested negative for Lso (liberibacter), the bacterium that causes zebra chip.

Overall psyllid captures have remained relatively steady over the last few weeks. However, we continue to urge growers to maintain their IPM programs.

“Heat maps” of this week’s results can be found on the UI and WSU websites linked below. The moderately “hot spot” observed during recent weeks in the western Treasure Valley remains, with another small area of moderate pressure south of Mountain Home.

This was the last sample week for quite a few of our fields, so we likely will not include heat maps next week given that they tend to be skewed with smaller sample sizes.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news
--Click on the links under “Updated weekly reports” for details on trap captures.
--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.
--WSU site: https://potatoes.decisionaid.systems/idaho

Potato Disease Spore Trapping Bulletin August 19th to 23rd specific to the late blight outbreak in Paul

Potato All Locations

Potato Late Blight

Posted on: August 28, 2019 by James Woodhall

Late blight outbreak in Paul – update

Phytophthora infestans has been reported in eight fields in the Paul area. The initial findings were on the 19th of August. There have been no new reports since Friday 23 August.

In the spore trap directly located in the outbreak area, Phytopthrora infestans was detected on three of the four days it was operating. No other spore traps tested positive for Phytophthora infestans this week, including the spore traps at Acequia and east of Rupert. Also, no critical periods of humidity have been observed since the 13th of August. Therefore the risk of late blight outside the affected area near Paul is likely to be less than last week.

It is likely that the outbreak at Paul was associated with periods of high humidity above 90% for several hours observed on 30th and 31st July and on the 8th, 9th and 10th of August. No periods of 90% relative humidity have been observed at the Paul weather station since the 13th of August.

Growers in the immediate area close to the outbreak are asked to remain vigilant and continue to taking measures to protect themselves against late blight through comprehensive scouting and applications of the appropriate fungicides. Growers in the wider Magic Valley, particularly east of Paul, are advised to continue being vigilant for the pathogen, particularly if humidity levels increase. Although weather does not appear to be conducive for disease development, airborne spores have been detected and a risk still remains.

No spores were detected at Rexburg this week. The last detection there was the 31st July. No periods of critical humidity (RH 90% and above) have been observed since the 9th of August. Risk levels can now be considered ‘normal’ for this area.

James Woodhall

Potato Disease Spore Trapping Bulletin August 12th to 18th plus further information on the late blight outbreak in Paul

Potato All Locations

Potato Late Blight

Posted on: August 22, 2019 by Juliet Marshall

At the request of Dr. James Woodhall, I am sending this late blight update. This is additional information to that sent yesterday by Dr. Jeff Miller.

News for the current week
Late blight disease was observed in six fields in the vicinity of Paul on Monday 19th August. This was confirmed by both PCR and LAMP and the genotype was determined to be US23.

Spores of Phytophthora infestans (late blight) were found on two days at Acequia and at one day in Rupert in spore traps (these are the two nearest traps to the outbreak).

Spores of Alternaria solani (early blight) were found at Parma (4 days), Golden Valley (1 day), Tetonia (1 day), Acequia (3 days) and Rupert (3 days).

Spores of Sclerotinia sclerotium (white mold) were found at Acequia (2 days) and Golden Valley (1 day).

Recommendations
Growers in the vicinity of the outbreak should include fungicides with activity to Phytohthora infestans in their spray program. Please consider that spores were found up to 15 miles away from the infected area (see risk maps attached).

Growers in the rest of the Magic Valley should be on high alert for Phytophthora infestans and actively scout for the disease and consider using appropriate fungicides in their spray program.

We also ask that growers in the Rexburg area continue to be vigilant and scout for the pathogen as a spore trap there was positive for P. infestans a few weeks ago.

The risk outside those areas is likely to be relatively low, prior to the detection in Rexburg on the 31st July, no other trap in the network has tested positive since June. Nevertheless please consider late blight has been reported in Idaho and is a potential source of inoculum.

Detailed information on late blight disease, its management, sources of help and diagnosis, are provided in the document attached.

Best wishes,

James, Kasia and Phill

» Late blight outbreak more information

» Map

» Graphic

Psyllid monitoring update 22 Aug 2019

Potato All Locations

Potato Psyllid

Posted on: August 22, 2019 by Lucy Standley

This week we had traps deployed in 78 of the 79 fields (98.7%) monitored this year, and we found a total of 52 psyllids across 26 (32.9%) of the 79 monitored fields. One of the 79 total fields that we were sampling has been vine-killed.

Psyllids were collected on sticky traps in potato in the following counties: Payette (3 fields), Canyon (9 fields), Owyhee (2 fields), Elmore (1 field), Twin Falls (6 fields), Jerome (3 fields), Cassia (1 field), and Minidoka (1 field).

All psyllids collected last week tested negative for Lso (liberibacter), the bacterium that causes zebra chip.

Overall psyllid captures have remained relatively steady over the last few weeks. However, we continue to urge growers to maintain their IPM programs.

“Heat maps” of this week’s results can be found on the UI and WSU websites linked below. The “hot spots” observed during recent weeks in the western Treasure Valley have diminished somewhat.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news
--Click on the links under “Updated weekly reports” for details on trap captures.
--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.
--WSU site: https://potatoes.decisionaid.systems/idaho

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/idaho

» August22EastMap

» August22WestMap

August 2019 Idaho outbreak of potato late blight – further information and recommendations

Potato All Locations

Late Blight

Posted on: August 22, 2019 by James Woodhall

Please see the attached sheets for more information on the current late blight outbreak in southern Idaho.

» Late_blight_2019_outbreak_info_(1).pdf

» Risk_levels.pdf

Late blight found in southwestern Minidoka County

Potato All Locations

Potato All Locations

Potato Psyllid

Posted on: August 1, 2019 by Lucy Standley

This week we had traps deployed in 81 of the 82 fields (98.7%) monitored this year, and we found a total of 67 psyllids across 27 (32.9%) of the 82 monitored fields. However, we are still waiting to receive traps from 19 sites in eastern Idaho. One of the 82 total fields that we were sampling has been vine-killed.

Psyllids were collected on sticky traps in potato in the following counties: Payette (3 fields), Canyon (12 fields), Owyhee (1 field), Elmore (3 fields), Twin Falls (6 fields), Cassia (1 field), and Minidoka (1 field).

All psyllids collected last week tested negative for Lso (liberibacter), the bacterium that causes zebra chip.

Psyllid captures dropped a bit relative to last week; however, we continue to urge growers to maintain their IPM programs, especially given that we have historically seen an increase in captures during August.

“Heat maps” of this week’s results will soon be included on the UI and WSU websites (see links below), pending resolution of technical difficulties we are currently having with them.

More information can be found here: http://www.uidaho.edu/cals/potatoes/news
--Click on the links under “Updated weekly reports” for details on trap captures.
--Click on the “Psyllid Management” link on the left panel for information on psyllid and zebra chip biology and management.
--WSU site: https://potatoes.decisionaid.systems/idaho

» http://www.uidaho.edu/cals/potatoes/news

» https://potatoes.decisionaid.systems/idaho

Potato Treasure Valley

Posted on: June 14, 2019 by Stuart Reitz

Potato psyllids detected in the Treasure Valley.

The potato pest monitoring network in Malheur County found potato psyllids in 45% of checked fields last week (Traps were placed May 31 and collected June 7). A total of 21 psyllids were collected this past week from the 20 fields currently in the monitoring network. The psyllids will be tested for the Zebra Chip bacterium.

For information on psyllid and other pest management in potatoes, please see the 2019 Integrated Pest Management Guidelines for Insects and Mites in Idaho, Oregon and Washington Potatoes, available at http://www.nwpotatoresearch.com/pest-library/pest-management-options/.

» http://www.nwpotatoresearch.com/pest-library/pest-management-options/

Potato herbicide solubility and effects - Spring 2019

Potato All Locations

Posted on: June 12, 2019 by Pamela Hutchinson

Rainfall across southern Idaho this spring has been unusually high in some areas and potato herbicides may have been or are being affected. Soluble herbicides can move downward in soil profile. Availability of herbicides for uptake can increase. What is happening with your potato herbicides and why? What is happening to your weeds and potatoes and why?

» Potato_herbicide_solubility_and_movement_-_Spring_2019.pdf

Annual University of Idaho Snake River Weed Management Tour - June 25th - Aberdeen R&E Center

Potato All Locations

Posted on: May 30, 2019 by Pam Hutchinson

Greetings;

Please mark your calendars and plan to attend the UI Snake River Pest Management Tour at the Aberdeen R&E Center on Tuesday June 25th.

Time: 8:30 to noon followed by a sponsored lunch.

Credits: Three Idaho pesticide applicator recertification credits will be offered.

Featured will be several weed control trials in potatoes, including tank mixtures, planned vs. rescue postemergence applications, chemigation vs sprinkler incorporation as well as potato variety herbicide tolerance trials, herbicide mechanism of action plots, and Litchi tomato herbicide management.

We hope to see you there.

Thanks,

Pam

p.s. This tour was originally scheduled for June 18th but due to cold rainy conditions, our potato and weed emergence has been slowed considerably

There will be no Snake River Tour at the Kimberly R&E Center this year – we plan to fire it up again in 2020!

Cull Potato Management

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cull potato managment

Posted on: May 13, 2019 by Kasia Duellman

The Idaho State Department of Agriculture requires cull potatoes from all potato operations to be rendered non-viable on a daily basis after April 15th in western Idaho and after May 15th in eastern Idaho. Dr. Kasia Duellman, UI CALS Extension Seed Potato Specialist has provided additional information about cull potato management. Click of the pdf below for additional information.

» Cull_Potato_Management-Pest-Alert_SUBMITTED.pdf

Potato Eastern Idaho

Potato All Locations

Posted on: November 14, 2016 by Jeff Miller

Potato All Locations

Posted on: August 30, 2016 by Nora Olsen

Harvest and Minimizing Foreign Material: On-line educational videos now available.

Foreign material is any material that is not the potato tuber. It is "trash" or "garbage" in potatoes. Many foreign materials originate in the field, but others enter the product stream through equipment and during storage and handling. Whether potatoes are destined for the fresh market or processing, foreign material is a great concern to the Idaho potato industry. By minimizing foreign material in the field, in storage, and in the processing plant, growers and processors help maintain a high-quality product, safe standards, and consumer confidence.

The video “Continuing to Manage Foreign Material for Quality Idaho Potatoes” outlines ways you can reduce unwanted or foreign material in your potatoes. The video (English and Spanish version) are available on-line at:

Spanish edition:
https://vimeo.com/144655993

English edition:
https://vimeo.com/144567198

Additional information “Managing Foreign Material for Quality Idaho Potatoes” is available at http://www.uidaho.edu/cals/potatoes/research/storage/potato-storage-management.

» https://vimeo.com/144567198

» https://vimeo.com/144655993

» http://www.uidaho.edu/cals/potatoes/research/storage/potato-storage-management.

Psyllid numbers remain high

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potato psyllids

Posted on: August 26, 2016 by Erik Wenninger

Potato psyllids were collected this week on sticky traps in potato in the following counties: Malheur (OR) (1 field), Payette (3 fields), Owyhee (5 fields), Canyon (13 fields), Ada (2 fields), Elmore (1 field), Gooding (2 fields), Twin Falls (7 fields), Jerome (6 fields), Minidoka (2 fields), and Cassia (4 fields). Additionally, potato psyllid nymphs (8 total) were captured on leaf samples from Ada County (2 fields) and Canyon County (1 field), and 42 potato psyllid adults were captured in vacuum samples taken from four Intense fields in Canyon and Ada counties.

This week, we collected 957 psyllids from sticky cards (727 from Light sites and 230 from Intense sites). Of the total 999 psyllids captured this week, 950 came from the Treasure Valley. We found psyllids in 46 of the 99 fields (46%) that were sampled this week. To put these numbers into perspective, we captured a total of approximately 1,100 psyllids for the entire year during each of the 2013 and 2015 seasons.

With the recent increase in psyllid numbers and attrition of our summer help, we ran Lso testing on a subset of psyllids collected last week (up to ten psyllids per site). So far, none of the psyllids tested last week was positive for Lso. About 25% of samples remain to be test, and we expect to have those Lso results early next week.

We scouted a few fields in the Magic Valley that have had Lso-positive psyllids this year and found no evidence of zebra chip in the plants that we sampled. This is encouraging. However, because of the recent prevalence of Lso and the relatively high numbers of potato psyllids that we have been collecting each week, we urge growers to maintain their IPM programs targeting psyllids and to be on the lookout for plants exhibiting ZC symptoms over the coming weeks. Foliar symptoms should be manifested about three weeks following infection, but will need to be confirmed by examining and testing tubers. See link below for description and photos of ZC symptoms, and please take suspicious plant samples to the Kimberly R&E Center or to your local UI Extension Center.

More information and resources on potato psyllids and ZC, including management, scouting recommendations, and ZC symptomology can be found at the links below.

http://oregonstate.edu/dept/hermiston/sites/default/files/pnw633_0.pdf

Detailed results from the “Light” sites can be found here:
https://docs.google.com/spreadsheets/d/1EruNcKgfqJ0RUpleaHBpODfwBZIqDyT4l-9MPKZBYcY/edit#gid=0

Detailed results from the “Intense” sites can be found here:
https://docs.google.com/spreadsheets/d/1Uk6GBxEgZeGWWhT84wymaWfHRs2it_Eg02eWPFLgWsI/edit#gid=0

» http://oregonstate.edu/dept/hermiston/sites/default/files/pnw633_0.pdf

» https://docs.google.com/spreadsheets/d/1EruNcKgfqJ0RUpleaHBpODfwBZIqDyT4l-9MPKZBYcY/edit#gid=0

» https://docs.google.com/spreadsheets/d/1Uk6GBxEgZeGWWhT84wymaWfHRs2it_Eg02eWPFLgWsI/edit#gid=0

Potato All Locations

Posted on: July 5, 2016 by Jeff Miller

The 2016 Miller Research Potato Pest Management Field Day will be held Wednesday, August 17 from 9:00-10:30 am. Please see the attached page for details.

Potato All Locations

Volunteer potatoes

Posted on: June 3, 2016 by Pam Hutchinson

Here’s an update to the recent article by Pamela Hutchinson, Potato Cropping Systems Weed Scientist at the University of Idaho Aberdeen R&E Center in SE Idaho, on methods for controlling volunteer potatoes. As previously mentioned, due to the mild winter experienced in the Pacific Northwest, tubers left after the 2015 harvest can and did survive. At this point in time (first week of June), volunteer plants may be past the tuber initiation, which has been shown to be the best stage for application of many herbicides for effective control, and to prevent re-sprouting and tuber production. However, that is not the case for all fields.

In addition, there are reports of newly emerging sprouts/plants after fields appear to have been sprayed. Fields should be monitored closely after an application in order to determine if further actions are needed!

Thanks,

Pam

» Volunteer Control Bulletin

» P. Hutchinson volunteer control recommendations

First Lso-positive potato psyllids found in Idaho potato fields this season

Potato All Locations

potato psyllids

Posted on: June 2, 2016 by Erik Wenninger

Both of the potato psyllids found last week (one in each of two potato fields in Canyon County) tested positive for liberibacter (Lso; the bacterium that causes zebra chip).

A more detailed update of trapping results from the past week will be posted on Friday.

We continue to urge growers and crop consultants to implement IPM programs for zebra chip. More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

Potato Psyllids in Malheur County

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Potato Psyllid

Posted on: May 28, 2016 by Stuart Reitz

We collected our first potato psyllids of the season from sticky cards in Malheur County potato fields. Two psyllids were found – one in each of two potato fields.

For information and resources on potato psyllids and zebra chip, including management and scouting recommendations, please see the following article: http://www.nwpotatoresearch.com/IPMStuff/PDFs/PotatoPsyllid.pdf.

Additional information on pest management in potatoes in the PNW is available at:
http://www.nwpotatoresearch.com/IPMStuff/PDFs/NorthwestInsectGuidelines.pdf

» http://www.nwpotatoresearch.com/IPMStuff/PDFs/PotatoPsyllid.pdf

» http://www.nwpotatoresearch.com/IPMStuff/PDFs/NorthwestInsectGuidelines.pdf

First potato psyllids found in Idaho potato fields this season

Potato All Locations

potato psyllids

Posted on: May 27, 2016 by Erik Wenninger

May 27, 2016 – First potato psyllids found in Idaho potato fields this year

We collected our first potato psyllids of the season from sticky cards in Idaho potato fields. Two psyllids were found – one in each of two potato fields in Canyon County. We found our first potato psyllids at a similar time last year.

Sticky cards have now been deployed in 66 of the estimated 97 fields that will be included in the monitoring program this year.

We urge growers and crop consultants to have an IPM program in place. More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.

http://www.uidaho.edu/extension/news/psyllid-management

Detailed results from the "Light" sites (from which the two psyllids were found) can be found here:
https://docs.google.com/spreadsheets/d/1EruNcKgfqJ0RUpleaHBpODfwBZIqDyT4l-9MPKZBYcY/edit#gid=0

Detailed results from the "Intense" sites can be found here:
https://docs.google.com/spreadsheets/d/1Uk6GBxEgZeGWWhT84wymaWfHRs2it_Eg02eWPFLgWsI/edit#gid=0

» http://www.uidaho.edu/extension/news/psyllid-management

» https://docs.google.com/spreadsheets/d/1EruNcKgfqJ0RUpleaHBpODfwBZIqDyT4l-9MPKZBYcY/edit#gid=0

» https://docs.google.com/spreadsheets/d/1Uk6GBxEgZeGWWhT84wymaWfHRs2it_Eg02eWPFLgWsI/edit#gid=0

2016 Potato psyllid monitoring program underway in Idaho

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potato psyllids

Posted on: May 13, 2016 by Erik Wenninger

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state will continue our monitoring program for potato psyllids, zebra chip, and liberibacter (Lso), the bacterium that causes zebra chip. The monitoring program covers commercial potato fields throughout southern Idaho and is funded in part by IPC, USDA, and generous in-kind contributions by our collaborators.

The first deployment of sticky cards on several of our sites occurred during the past week. More details on the program will be forthcoming, but it will be similar to what we’ve done over the last three years.

More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.

http://www.uidaho.edu/extension/news/psyllid-management

Clarification on seed treatment for late blight

Potato All Locations

Late Blight

Posted on: April 1, 2016 by Jeff Miller

A point of clarification on the announcement for using seed piece treatments to manage late blight: State registrations have not yet been granted in ID, OR or WA for the use of Revus at this time. However, it is expected soon. Do not use Revus until the state registrations are in place. If you are going to use a seed treatment for late blight and the state registration is not in place, please choose another fungicide.

Seed treatment for late blight management in potato

Potato All Locations

Late Blight

Posted on: March 31, 2016 by Jeff Miller

The widespread presence of late blight in 2015 has created the possibility of late blight coming into commercial potato production through infected seed. If growers suspect their seed may have late blight, they should treat with a seed treatment effective against late blight. Mancozeb dust (6%) is an effective treatment. Some liquid seed treatments are also available and research has shown them to be more effective than just using 6% MZ dust alone. Curzate (cymoxanil), Reason (fenamidone), and now Revus (mandipropamid) are labeled for treatment of seed for the control of late blight.

2015 Miller Research Potato Pest Management Workshop

Potato All Locations

Posted on: November 18, 2015 by Jeff Miller

Miller Research LLC will be holding its annual potato pest management seminar on December 8, 14, and 15. The same program will be held on all three days. Please RSVP as seating in each session is limited to 45. The meetings will be held at the Miller Research facility located near Rupert, ID (426 E 200 N). Lunch will be provided. There is no cost to attend the meeting. CCA and ISDA credits have been requested.

More information can be found at the accompanying link and in the attached flier.

» http://www.millerresearch.com/alerts/research-news/item/53-mr-potato-pest-management-workshop

» 2015_MR_Workshop_Flier.pdf

ZC-positive plants found in potato fields in Minidoka and Twin Falls counties

Potato All Locations

Potato Psyllid

Posted on: October 2, 2015 by Amy Carroll

Tubers sampled from a potato field in Minidoka County and a field in Twin Falls County tested positive for liberibacter (Lso), the bacterium that causes zebra chip (ZC). So far this season we are aware of four fields in Idaho with confirmed ZC. Earlier this season we reported finding Lso-positive tubers from Ada and Power counties.

As the season winds down, we encourage growers and crop consultants to be on the lookout for symptomatic tubers.

Photos of typical ZC symptoms exhibited by foliage and tubers may be found here:
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Consult our website for more information, including management recommendations and online spreadsheets that show details of the psyllid captures in potato fields over the season. http://www.uidaho.edu/extension/news/psyllid-management

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

» http://www.uidaho.edu/extension/news/psyllid-management

Late blight found in Payette County

Potato All Locations

Late blight

Posted on: October 1, 2015 by Nora Olsen

Late blight infected tubers were identified from Payette County. Foliar late blight was not previously reported in this area. The strain was identified as US-23. Continue to submit diseased tubers for sampling in all Idaho regions and counties.

Potato All Locations

Late blight

Posted on: August 20, 2015 by Jeff Miller

Meetings were held in American Falls and Idaho Falls on August 18 focused on providing information on late blight management in potato. PowerPoint handouts from those meetings are attached here. The first reviews management in the field up until harvest. The second discusses storage management. The third discusses vine kill as it relates to late blight management.

» Managing Late Blight Late Season

» Managing Late Blight in Storage

» Vine Kill Considerations for Late Blight Management

Clarification on late blight meeting

Potato All Locations

Late blight

Posted on: August 14, 2015 by Jeff Miller

The previous alert did not specify the locations for the late blight management meetings:

American Falls at the American Falls High School Auditorium - Tuesday, August 18 from 10:00 am -12:00 pm

Idaho Falls at the University of Idaho (Tingey Administration Building auditorium) – Tuesday, August 18 from 1:30 pm – 3:30 pm

Managing Late Blight Going into Storage

Potato All Locations

Late blight

Posted on: August 14, 2015 by Jeff Miller

Please note that the American Falls meeting outlined below replaces the meeting planned for Aberdeen!

The University of Idaho and Miller Research are sponsoring a meeting on managing late blight going into storage. The meeting agendas are as follows:

American Falls - Tuesday, August 18 from 10:00 am -12:00 pm.

Idaho Falls – Tuesday, August 18 from 1:30 pm – 3:30 pm

Dr. Jeff Miller will speak first and discuss proper disease identification, pathogen life cycle and biology, disease management considerations in the field, and appropriate use of fungicides late season through vine kill.

Dr. Nora OIsen will discuss post –harvest fungicide use and selection and proper storage management considerations.

Two ISDA recertification credits are available.

potato psyllid update

Potato All Locations

potato psyllids

Posted on: August 14, 2015 by Erik Wenninger

Abundance of potato psyllids captured in potato fields in Idaho is up slightly from last week. We captured 63 psyllids on sticky cards in fields across the Treasure and Magic Valleys, including fields in Payette, Canyon, Ada, Owyhee, Elmore, Gooding, Twin Falls, Jerome, and Cassia counties. In addition, we found one potato psyllid nymph on a leaf sample from a field in Gooding County.

All of the psyllids collected last week (cards deployed during the week of July 26 and collected during the week of August 2) tested negative for liberibacter (Lso), the bacterium that causes zebra chip.

We captured 43 psyllids from our fortnightly bittersweet nightshade sampling around the Treasure and Magic Valleys. This also is up slightly from the previous samples.

We collected tubers this week and last from several fields that have had the highest incidence of liberibacter-positive psyllids. Foliar symptoms were mostly lacking and, although most tubers examined were clean, a few were found with apparent zebra chip (ZC) symptoms. These samples are being tested for liberibacter, which is the only way to determine with certainty whether or not the plants actually have ZC.

Although all psyllids collected last week were negative for liberibacter and tuber samples that we have examined have been mostly clean, the level of liberibacter found in psyllid samples from Canyon and Ada counties during recent weeks suggests that risk of ZC may be higher in this area. Therefore, we encourage growers and crop consultants to scout for symptomatic plants and to consider this risk level when making insecticide decisions through the remainder of the season.

Photos of typical ZC symptoms exhibited by foliage and tubers may be found here:
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Consult our website for more information, including management recommendations and online spreadsheets that show details of the psyllid captures in potato fields over the season. Updates to these spreadsheets may occur throughout the week as liberibacter testing results come in.
http://www.uidaho.edu/extension/news/psyllid-management

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

» http://www.uidaho.edu/extension/news/psyllid-management

Late blight management meeting

Potato All Locations

Late blight

Posted on: August 14, 2015 by Jeff Miller

A meeting on managing late blight going into storage will be held at the Aberdeen High School on Tuesday, August 18 at 10:00 AM. Speakers will be Dr. Nora Olsen (University of Idaho) and Dr. Jeff Miller (Miller Research). Call Jeff at 208-431-4420 for more information.

More late blight samples

Potato All Locations

Late blight

Posted on: August 14, 2015 by Jeff Miller

Late blight had been confirmed in additional counties. Positive samples were confirmed in Madison, Fremont, and Jefferson counties yesterday and this morning. Two samples have also been confirmed in Cassia County - one on the east side an another on the west.

Late blight in Cassia, Madison, Fremont, and Jefferson Count

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Late blight

Posted on: August 13, 2015 by Jeff Miller

Late blight had been confirmed in additional counties. Positive samples were confirmed in Madison, Fremont, and Jefferson counties yesterday and this morning. Two samples have also been confirmed in Cassia County - one on the east side an another on the west.

Potato Diseases Update

Potato Eastern Idaho

late blight, early blight, white mold, bacterial stem rot

Posted on: August 8, 2015 by Phillip Wharton

In the Treasure Valley area Dr. Mike Thornton reports that they are primarily seeing white mold, bacterial stem rot and early blight. The crop is beginning to senescence in some fields, and growers should be carefully monitoring soil moisture to make sure they match water applications to crop use.

In the rest of southern and south eastern Idaho conditions remain favorable for late blight. With the current frequent rain showers and thunderstorms moving through the area and cooler night time temperatures growers should be very vigilant for late blight. In the past two weeks, Dr. Jeff Miller has reported that most of the late blight out breaks have been spread by the thunderstorms moving through the area. This is evident by the uniform levels of disease spread throughout infected fields instead of in isolated infection points or at the edge of fields spreading inwards.

In the past week, the University of Idaho has confirmed 4 more positive infections in Power county and two more in Bingham county but none in Minidoka county. To date, the late bight out breaks appear to be limited to these three counties. All isolates from these outbreaks have been identified as the US 23 genotype and mefenoxam (Ridomil) sensitive.

As we move towards harvest, growers affected by late blight need to be aggressive in managing the disease at the end of the season and going into storage. Growers should be aware that in addition to attacking foliage, late blight can infect tubers at any stage of development before and after harvest and in storage, with symptoms and rot usually only showing up in storage. Late blight infection of tubers is characterized by irregularly shaped, slightly depressed brown to purplish areas on the skin. These symptoms may be less obvious on russet and red-skinned cultivars. A tan to reddish-brown, dry, granular rot is found under the skin in the discolored area, extending into the tuber usually less than half an inch. For more information and photos of late blight tuber symptoms see the attached link (http://bit.ly/1KWFt6a).

Late in the season it is advisable to avoid excessive irrigation as tubers become infected with late blight when spores wash down through the soil from infected leaves. Vines should also be killed at least two weeks before harvest, especially in blight infected fields. This interval minimizes the chance of tubers getting contaminated with late blight inoculum during harvest, and allows previously infected tubers to decompose in the field. If blight is present in the field or in the vicinity of the field at harvest, it may also be beneficial to spray foliage after vine killing with labeled fungicides to kill living late blight spores on the foliage.

For more detailed information on a late season checklist for managing late blight and fungicide fungicide recommendations see the attached link (http://bit.ly/1Kb3ELg).

For up to date information on potato diseases in Idaho and across the country follow us on twitter. http://www.twitter.com/potatodiseases

» http://bit.ly/1KWFt6a

» http://bit.ly/1Kb3ELg

Late blight update

Potato All Locations

Late blight

Posted on: August 8, 2015 by Jeff Miller

Late blight is spreading in several locations in southern Idaho. Please see the attached "Late blight update" for a summary of the epidemic and an overview of control measure. We have also attached a review of fungicides available for late blight control along with a checklist for managing late blight going into storage.

Links to web pages from the University of Idaho and Miller Research with additional information are listed below.

» http://www.millerresearch.com/alerts/pest-alerts/item/49-late-blight-management-2015

» http://www.idahopotatodiseases.org/lateblight.html

» Late blight update, Aug. 7

» Overview of fungicides for late blight control

» Checklist for managing late blight into storage

Potato psyllid abundance similar to recent weeks; more Lso-p

Potato All Locations

potato psyllids

Posted on: August 7, 2015 by Erik Wenninger

Abundance of potato psyllids in potato fields in Idaho this week was similar to the past two weeks, if not slightly lower. We captured 37 psyllids on sticky cards in fields across the Treasure and Magic Valleys, including fields in Payette, Canyon, Ada, Owyhee, Elmore, Gooding, Twin Falls, Jerome, and Cassia. In addition, we found a potato psyllid on a card from a field in Power County that was collected last week and submitted to our lab this week.

From week 10 of sampling (cards deployed the week of July 12th and collected the week of the 19th), we collected 14 psyllids that tested positive for liberibacter (Lso), the bacterium that causes zebra chip. All were from fields in Canyon or Ada counties.

From week 11 we had several psyllids, mostly in the Treasure Valley, that tested positive for liberibacter (Lso), the bacterium that causes zebra chip. Positive psyllids were found in Payette County, Canyon County (four different fields), Ada County (15 positive psyllids in one field), Owyhee County, and Twin Falls County. In addition, we found positive psyllids at our bittersweet nightshade site in Murtaugh and at Dierkes Lake in Twin Falls (one from each site).

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields over the season. Updates to these spreadsheets may occur throughout the week as Lso testing results come in.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

More positive psyllids in Ada County; first Payette and Powe

Potato All Locations

Potato Psyllid

Posted on: July 31, 2015 by Erik Wenninger

Abundance of potato psyllids in potato fields in Idaho this week slightly increased, with 57 psyllids captured (compared to 43 last week) across the Treasure Valley, Magic Valley, and Upper Snake. Psyllids were captured this week from several fields in Ada and Canyon counties, as well as from sites in Owyhee, Payette, Twin Falls, Jerome, Cassia and Power counties. This represents the first psyllid captured in Payette as well as in Power County.

Last week we were waiting for results from psyllids captured on cards deployed in potato fields July 6th to 13th. Five psyllids from two different fields in Ada County tested positive for liberibacter (Lso), the bacterium that causes zebra chip. We continue to run a little behind receiving results, but they will be posted on the website below as soon as they come in. Please continue checking throughout the week. We are still waiting on results from psyllids captured last week.

We captured 27 psyllids at our bittersweet nightshade sites around the Treasure and Magic Valleys.

We continue to urge growers and crop consultants to have an IPM program in place and to supplement our monitoring program with their own local monitoring.

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields over the season. Updates to these spreadsheets may occur throughout the week as Lso testing results come in.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

Late blight

Potato All Locations

Posted on: July 28, 2015 by Jeff Miller

The late blight in Minidoka County has been determined to be the US-23 strain. This strain is sensitive to mefenoxam. As a result, growers can use Ridomil Gold pre-packs (e.g. Ridomil Gold Bravo, Ridomil Gold MZ) to manage late blight. Fields which have been treated with mefenoxam appear to be free of late blight even though they are close to fields with confirmed late blight.

Additional fields in Minidoka County have been confirmed, with the latest finds close to Rupert.

More information on fungicides for managing late blight can be found at the link below.

» http://www.millerresearch.com/agricultural-research/agricultural-research-reports/potato-research-reports/late-blight/item/44-late-blight-fungicide-management

Zero positive potato psyllids from last week

Potato All Locations

Potato Psyllid

Posted on: July 24, 2015 by Amy Carroll

Overall abundance of potato psyllids in potato fields in Idaho this week continued to decline, with 43 psyllids captured (compared to 71 last week) across the Treasure and Magic Valleys. Psyllids were captured this week from several fields in Ada and Canyon counties, as well as from a few different sites in Elmore and Twin Falls counties. We are still waiting on a shipment of sticky cards from our “Light” sites (approximately 20 fields) in Cassia and Minidoka counties.

Zero psyllids from last week tested positive for liberibacter (Lso), the bacterium that causes zebra chip—one each from Canyon, Ada, and Minidoka counties.

We continue to urge growers and crop consultants to have an IPM program in place and to supplement our monitoring program with their own local monitoring.

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields over the season. Updates to these spreadsheets may occur throughout the week as Lso testing results come in.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

More late blight in Minidoka County

Potato All Locations

Late blight

Posted on: July 22, 2015 by Jeff Miller

Late blight had been confirmed in two additional fields in Minidoka County. It is likely in several others. Pathogen spread is likely with current weather conditions. Growers are encouraged to report additional finds so that the extent of infection and rate of spread can be documented.

Potato Pest Management Field Day

Potato All Locations

Posted on: July 21, 2015 by Jeff Miller

Miller Research will be holding a pest management field day on Thursday, August 13 at the Miller Research facility located near Acequia, ID (426 E 200 N). A short presentation will be given in the office followed by a tour of the research plots.

The presentations will focus on and chemical management of diseases and will highlight research which has been funded by the Pacific Northwest Potato Research Consortium. We have requested 3 ISDA pesticide recertification credits and 3 CCA (Pest Management) credits for this meeting.

Lunch will be provided. Please RSVP to Jeff Miller by August 10 at 208-531-5124 or by email at: jeff@millerresearch.com so that we can get an accurate count for room preparation purposes.

See the attachment for additional details.

» 2015 Miller Research Potato Pest Management Field Day

Late blight in Minidoka County

Potato All Locations

Late blight

Posted on: July 21, 2015 by Jeff Miller

Late blight has been positively identified in Minidoka County. It appears the infections resulted from a spore shower and it is likely that other fields are also affected. It is critical for growers to scout fields. Affected fields should be sprayed on a 7-day schedule. If thundershowers persist, a 7-day schedule is advised for all in the area. Management guidelines are available at the link below.

» http://www.millerresearch.com/alerts/pest-alerts/item/49-late-blight-management-2015

» Infection at plant apex

» Early petiole infection

» Stem lesion

Weekly Potato Disease Update

Potato Eastern Idaho

Potato All Locations

Posted on: June 26, 2015 by Phill Wharton

Dr. Mike Thornton reports that there are not a lot of disease issues coming through the door right now. In the Treasure Valley area, we are seeing a little bit of early blight on lower leaves, especially on plants that are stressed due to virus infection or other issues. Speaking of stress, the hot days and warm nights forecast for the next week or so can be very hard on potato plants. To reduce the incidence of physiological disorders like sugar ends, it is important to adjust irrigation schedules to account for the increase in water demand by the crop. Growers cannot afford to get behind on irrigation under these conditions, as even a single stress event at this critical time of tuber development can cause high levels of malformed tubers and reduce processing quality.

In the Magic Valley area Dr. Nora Olsen reports that the only significant disease issues they are seeing are related to PVY infection of potatoes. The high temperatures in the area also appear to be putting some crops under stress as many which were almost at row closure last week still have not closed rows yet this week.

In east and north eastern part of the state Pocatello up through Tetonia), there have been no disease problems reported apart from some PVY issues. Many crops are at flowering now and should be at row closure in the next week or so. As with other parts of the state hot days and warm nights are forecast for the next couple of days so it is imperative to adjust irrigation schedules to account for the increase in water demand by the crop. Increased stress on the plants can make them more susceptible to disease and insect problems.

For up to date information on potato diseases in Idaho and across the country follow us on twitter. http://www.twitter.com/potatodiseases

» 1193_1.pdf

Potato Pest Alert for the week ending 6-26-2015

Potato All Locations

Posted on: June 26, 2015 by Phill Wharton

Dr. Mike Thornton reports that there are not a lot of disease issues coming through the door right now. In the Treasure Valley area, we are seeing a little bit of early blight on lower leaves, especially on plants that are stressed due to virus infection or other issues. Speaking of stress, the hot days and warm nights forecast for the next week or so can be very hard on potato plants. To reduce the incidence of physiological disorders like sugar ends, it is important to adjust irrigation schedules to account for the increase in water demand by the crop. Growers cannot afford to get behind on irrigation under these conditions, as even a single stress event at this critical time of tuber development can cause high levels of malformed tubers and reduce processing quality.

In the Magic Valley area Dr. Nora Olsen reports that the only significant disease issues they are seeing are related to PVY infection of potatoes. The high temperatures in the area also appear to be putting some crops under stress as many which were almost at row closure last week still have not closed rows yet this week.

In east and north eastern part of the state Pocatello up through Tetonia), there have been no disease problems reported apart from some PVY issues. Many crops are at flowering now and should be at row closure in the next week or so. As with other parts of the state hot days and warm nights are forecast for the next couple of days so it is imperative to adjust irrigation schedules to account for the increase in water demand by the crop. Increased stress on the plants can make them more susceptible to disease and insect problems.

For up to date information on potato diseases in Idaho and across the country follow us on twitter. http://www.twitter.com/potatodiseases

» 1193_1.pdf

Potato Pest Alert for the week ending 6-19-2015

Potato All Locations

Posted on: June 19, 2015 by Phill Wharton

Potato All Locations

Posted on: June 12, 2015 by Phill Wharton

Pest Alert for the week ending 6-12-2015

Welcome to the new weekly potato disease update for southern Idaho. For the rest of the growing season we will be posting weekly disease updates from around the potato growing regions in southern Idaho.

Dr. Mike Thornton reports that rows are closed/closing in most fields in the Treasure Valley region so growers are focused on late blight/ early blight/ white mold fungicide applications. There have been reports from across the state of some seed lots with relatively high incidences of PVY. With all the excess rain that we had in May, some growers are reporting problems with Fusarium seed piece decay after planting (see http://bit.ly/1FdrZNw for more information).

With the wet May weeds have been more of a problem this spring and are expected to be a problem as the season progresses. Dr. Pam Hutchinson produced a handy article on how to deal with weeds in your potatoes this year (http://bit.ly/1MPv3pq).

The very mild winter we had has also led to a big problem this year with volunteer potatoes showing up across the state (http://bit.ly/1Thgv6p). Volunteer potatoes can harbor diseases such as late blight and increase the risk of a late blight epidemic. For information on what fungicides to use for managing late blight see the article recently published by Dr. Jeff Miller of Miller Research and Dr. Phill Wharton from UI (http://bit.ly/1Q4tmty).

For up to date information on potato diseases in Idaho and across the country follow us on twitter. http://www.twitter.com/potatodiseases

» http://bit.ly/1FdrZNw

» http://bit.ly/1Thgv6p

» http://bit.ly/1Q4tmty

Potato Pest Alert for the week ending 6-12-2015

Potato All Locations

Posted on: June 12, 2015 by Phill Wharton

Pest Alert for the week ending 6-12-2015

Welcome to the new weekly potato disease update for southern Idaho. For the rest of the growing season we will be posting weekly disease updates from around the potato growing regions in southern Idaho.

Dr. Mike Thornton reports that rows are closed/closing in most fields in the Treasure Valley region so growers are focused on late blight/ early blight/ white mold fungicide applications. There have been reports from across the state of some seed lots with relatively high incidences of PVY. With all the excess rain that we had in May, some growers are reporting problems with Fusarium seed piece decay after planting (see http://bit.ly/1FdrZNw for more information).

With the wet May weeds have been more of a problem this spring and are expected to be a problem as the season progresses. Dr. Pam Hutchinson produced a handy article on how to deal with weeds in your potatoes this year (http://bit.ly/1MPv3pq).

The very mild winter we had has also led to a big problem this year with volunteer potatoes showing up across the state (http://bit.ly/1Thgv6p). Volunteer potatoes can harbor diseases such as late blight and increase the risk of a late blight epidemic. For information on what fungicides to use for managing late blight see the article recently published by Dr. Jeff Miller of Miller Research and Dr. Phill Wharton from UI (http://bit.ly/1Q4tmty).

For up to date information on potato diseases in Idaho and across the country follow us on twitter. http://www.twitter.com/potatodiseases

» http://bit.ly/1FdrZNw

» http://bit.ly/1Thgv6p

» http://bit.ly/1Q4tmty

First Lso-positive psyllid found in a potato field in Idaho

Potato All Locations

potato psyllids

Posted on: June 12, 2015 by Erik Wenninger

One of the psyllids (from Ada County) that we found last week in potato fields tested positive for Lso, the bacterium that causes zebra chip. The remaining psyllids that we collected last week tested negative for Lso.

This week we found more psyllids on sticky traps in potato fields in the following counties: Canyon, Ada, Gooding (two different fields), and Twin Falls (two different fields). In addition, suspected potato psyllids from a field in Owyhee County and an additional field in Canyon County are being shipped to us for confirmation, which should occur on Monday.

Last week, in a partnership with ISDA, we inspected for potato psyllids on tomato and pepper plants at four different retail nurseries in the Twin Falls area and found no psyllids. This week we inspected four different retail nurseries in the Burley area and found one tomato plant with many psyllid nymphs. These are being tested for Lso. The importance of retail nurseries in harboring potato psyllids and Lso remains to be clarified, but this is one possible source of the disease.

We continue to urge growers and crop consultants to have an IPM program in place and to begin local monitoring of fields, especially near the recent findings of Lso-positive psyllids.

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields over the season. Updates to these spreadsheets may occur throughout the week as Lso testing results come in.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

First Lso-positive psyllid found in a potato field in Idaho

Potato All Locations

potato psyllids

Posted on: June 12, 2015 by Erik Wenninger

One of the psyllids (from Ada County) that we found last week in potato fields tested positive for Lso, the bacterium that causes zebra chip. The remaining psyllids that we collected last week tested negative for Lso.

This week we found more psyllids on sticky traps in potato fields in the following counties: Canyon, Ada, Gooding (two different fields), and Twin Falls (two different fields). In addition, suspected potato psyllids from a field in Owyhee County and an additional field in Canyon County are being shipped to us for confirmation, which should occur on Monday.

Last week, in a partnership with ISDA, we inspected for potato psyllids on tomato and pepper plants at four different retail nurseries in the Twin Falls area and found no psyllids. This week we inspected four different retail nurseries in the Burley area and found one tomato plant with many psyllid nymphs. These are being tested for Lso. The importance of retail nurseries in harboring potato psyllids and Lso remains to be clarified, but this is one possible source of the disease.

We continue to urge growers and crop consultants to have an IPM program in place and to begin local monitoring of fields, especially near the recent findings of Lso-positive psyllids.

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields over the season. Updates to these spreadsheets may occur throughout the week as Lso testing results come in.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

Potato psyllids found in more potato fields and bittersweet

Potato All Locations

potato psyllids

Posted on: June 5, 2015 by Erik Wenninger

The one potato psyllid that we found in a potato field last week tested negative for Lso, the bacterium that causes zebra chip.

This week we found more potato psyllids in potato fields, including one psyllid on a sticky trap in each of five different fields (three in Canyon County, one in Ada County, and one in Jerome County). We also found one psyllid in a vacuum sample from a different Jerome County field.

From our bittersweet nightshade sites, we found 25 potato psyllids from among three of our sites in Twin Falls County and one psyllid from one of our Ada county sites.

This week, in a partnership with ISDA, we inspected for potato psyllids on tomato and pepper plants at four different retail nurseries in the Twin Falls area. Although we had found potato psyllids in nurseries in previous years, we were unable to find any during this inspection.

We continue to urge growers and crop consultants to have an IPM program in place and to begin local monitoring of fields.

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

Potato psyllids found in more potato fields and bittersweet

Potato All Locations

potato psyllids

Posted on: June 5, 2015 by Erik Wenninger

The one potato psyllid that we found in a potato field last week tested negative for Lso, the bacterium that causes zebra chip.

This week we found more potato psyllids in potato fields, including one psyllid on a sticky trap in each of five different fields (three in Canyon County, one in Ada County, and one in Jerome County). We also found one psyllid in a vacuum sample from a different Jerome County field.

From our bittersweet nightshade sites, we found 25 potato psyllids from among three of our sites in Twin Falls County and one psyllid from one of our Ada county sites.

This week, in a partnership with ISDA, we inspected for potato psyllids on tomato and pepper plants at four different retail nurseries in the Twin Falls area. Although we had found potato psyllids in nurseries in previous years, we were unable to find any during this inspection.

We continue to urge growers and crop consultants to have an IPM program in place and to begin local monitoring of fields.

Consult our website for more information, including online spreadsheets that show details of the psyllid captures in potato fields.

http://www.uidaho.edu/extension/news/psyllid-management

» http://www.uidaho.edu/extension/news/psyllid-management

Potato Eastern Idaho

» https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdGVrX2t2NGs0YzlYYUZaQkNaejhES2c#gid=0

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

Idaho psyllid monitoring update

Potato All Locations

Posted on: June 13, 2014 by Erik Wenninger

No new psyllids were found this week in University of Idaho’s potato psyllid monitoring program, and all psyllids collected so far have been negative for liberibacter (Lso, the bacterium that causes zebra chip). This includes the few psyllids collected from bittersweet nightshade plants in Twin Falls County that had yet to be tested as well as some potato psyllids found on pepper plants at a local garden center.

We still encourage monitoring of potato psyllids throughout the Treasure and Magic Valleys, and insecticide programs should be prepared.

Online spreadsheets with detailed results of psyllid captures are available at the links below. These are updated periodically over the week as data comes into our lab.

Results for the “intense” fields, which are monitored with 10 sticky traps, vacuum samples, and leaf samples are here:
https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdG15WTNRMkEteHRWRGhpM2ltSXBiR3c#gid=0

Results for the “light” fields, which are monitored with 4 sticky traps are here:
https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdGVrX2t2NGs0YzlYYUZaQkNaejhES2c#gid=0

More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.
http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

» https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdG15WTNRMkEteHRWRGhpM2ltSXBiR3c#gid=0

» https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdGVrX2t2NGs0YzlYYUZaQkNaejhES2c#gid=0

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

Idaho potato psyllid monitoring update

Potato All Locations

potato psyllids

Posted on: June 9, 2014 by Erik Wenninger

Last week we reported finding six potato psyllids across potato fields in Malheur (Oregon), Payette, and Canyon Counties. The sticky traps were collected by one of our cooperators, and we regret to report that there was a miscommunication regarding whether these potato psyllid identifications had been confirmed by an expert entomologist. After arrival of the samples at the Kimberly R&E Center over the weekend, we confirmed that these were NOT potato psyllids. We apologize sincerely for the error. All future samples will run through our lab (or a qualified entomologist known to our program) before being reported (this has always been our policy, but a miscommunication regarding whether this had happened caused this mistake).

Although we now have no confirmed potato psyllid captures in potato fields in the Treasure Valley, we do have confirmed reports of potato psyllids in the Columbia Basin (both Washington and Oregon), and we have confirmed potato psyllids from our sampling network in Jerome County (potato field) and Twin Falls County (bittersweet nightshade sites). Therefore, monitoring throughout the Treasure and Magic Valleys should be increased and insecticide programs should be prepared.

All potato psyllids tested so far for liberibacter (Lso, the bacterium that causes zebra chip) have been negative. This includes the psyllid found in Jerome County and the first three psyllids found on bittersweet nightshade plants in Twin Falls County.

The online spreadsheets with updates of psyllid captures occurring throughout the week are up and running. Results for the “intense” fields, which are monitored with 10 sticky traps, vacuum samples, and leaf samples are here:

https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdG15WTNRMkEteHRWRGhpM2ltSXBiR3c#gid=0

Results for the “light” fields, which are monitored with 4 sticky traps are here:

https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdGVrX2t2NGs0YzlYYUZaQkNaejhES2c#gid=0

More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.

http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

» https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdG15WTNRMkEteHRWRGhpM2ltSXBiR3c#gid=0

» https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdGVrX2t2NGs0YzlYYUZaQkNaejhES2c#gid=0

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

More potato psyllids found in Idaho potato fields

Potato All Locations

potato psyllids

Posted on: June 7, 2014 by Erik Wenninger

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state initiated a scouting program during the week of May 18 that covers commercial potato fields throughout southern Idaho.

Earlier this week, we reported finding one potato psyllid on a yellow sticky trap in a potato field in Jerome County. In addition, this week on yellow sticky traps we have found a total of six more psyllids across four potato fields located in Malheur (Oregon), Payette, and Canyon Counties.

This week we also collected six psyllids across two bittersweet nightshade sites in Twin Falls County.

All of these psyllids have been sent to the main campus to be tested for liberibacter (Lso), the bacterium that causes zebra chip disease.

The online spreadsheet that shows detailed results of the monitoring efforts and location of fields (by county) will be available very soon.

More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.

http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

First 2014 potato psyllid found in Idaho potato field

Potato All Locations

potato psyllids

Posted on: June 4, 2014 by Erik Wenninger

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state initiated a scouting program during the week of May 18 that covers commercial potato fields throughout southern Idaho. The project is funded in part by IPC, ISDA, and USDA. Thirteen fields are being monitored weekly with 10 yellow sticky cards, vacuum samples, and leaf samples. Approximately 75 additional fields are being monitored weekly with 4 yellow sticky cards; scouting efforts in some fields (especially in eastern Idaho) are still being initiated.

Our first potato psyllid was found in Jerome County on a sticky card that was deployed May 27 and retrieved June 3. This psyllid is being overnighted to the main campus to be tested for liberibacter (Lso), the bacterium that causes zebra chip disease.

We still have more sticky traps from this week that remain to be read. By the end of this week we will provide access to an online spreadsheet that shows results of the monitoring efforts and location of fields (by county).

More information and resources on potato psyllids and zebra chip, including management and scouting recommendations, can be found at the link below.

http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

Colorado Potato Beetle

Potato Treasure Valley

Colorado Potato Beetle

Posted on: May 28, 2014 by Stuart Reitz

Overwintering Colorado Potato Beetle adults are beginning to emerge in southwest Idaho. The overwintering adult stage does little damage; however, females are beginning to lay eggs in potato fields. We could see the damaging larvae appear in about 7 to 10 days depending on temperatures. This is the time for growers to be scouting for CPB, especially if they plan to use "soft" foliar insecticides that target control of early instar larvae.

To guard against development of insecticide resistance, post-emergence applications of neonicotinoid insecticides should not be used if a neonicotinoid seed treatment or other at-planting neonicotinoid treatment was used. Examples of neonicotinoid seed or at-planting treatments include Admire, Belay, Cruiser, Gaucho, and Platinum. Examples of foliar neonicotinoid sprays include Actara, Assail, Belay, Endigo ZC, Leverage, Provado and Scorpion.

» CPB Adult

» CPB Eggs

» CPB Larvae

Miller Research Potato Pest Management Meeting

Potato All Locations

Posted on: December 3, 2013 by Jeff Miller

The 2013 Miller Research Potato Pest Management Seminar will be held December 16 and 17 (same program both days). The meetings start at 9:00 and conclude at 12:30. The cost is $10 and lunch will be provided. If you are planning on attending, but have not responded, please RSVP so that we can plan appropriately for lunch. A total of 3 CCA (integrated pest management) and 3 ISDA pesticide recertification credits are available. A complete agenda can be found on the attached flier.

» 2013 Potato Pest Management Seminar

Potato Pest Management Meeting

Potato All Locations

Posted on: November 15, 2013 by Jeff Miller

Miller Research LLC will be holding its annual potato pest management research meeting on Monday, December 16 and Tuesday, December 17. The same program will be repeated both days and seating in each session is limited to 45. The meetings will be held at the Miller Research facility located near Acequia, ID (426 E 200 N). The cost to attend is $10 and lunch will be provided. A detailed agenda with program topics is attached.

Please RSVP as to which session you would like to attend to Jeff Miller at 208-531-5124 or by email at: jeff@millerresearch.com so that we can get an accurate count for lunch and room preparation purposes.

A total of 3 ISDA pesticide recertification credits have been requested and 3 CCA credits (Integrated Pest Management) have been awarded.

» http://www.millerresearch.com/alerts/research-news/item/43-mr-potato-pest-management-workshop

» 1038_1.pdf

potato psyllid & ZC update

Potato All Locations

potato psyllids and ZC

Posted on: September 27, 2013 by Erik Wenninger

Nearly all of the fields in the U-Idaho potato psyllid monitoring program have undergone vine kill. Of the sites still being monitored, psyllid numbers are for the most part similar to counts from recent weeks. On a few sites we recorded psyllids for the first time this year. We are still waiting on some Lso testing results, but so far no new psyllids have tested positive for Lso, the bacterium that causes ZC. A few vine-killed / harvested sites in the Magic and Treasure Valleys that tended to have had the most psyllids will continue to be monitored for a few more weeks. In addition, suspected overwintering sites will be monitored during the off-season.

Detailed monitoring results can be found here:
http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

» http://www.millerresearch.com/agricultural-research/agricultural-research-reports/potato-research-reports/late-blight/item/44-late-blight-fungicide-management

» University of Idaho Update and Recommendations

Potato All Locations

Posted on: August 2, 2013 by Jeff Miller

Miller Research will be holding a pest management field day on Wednesday, August 14 at the Miller Research facility located near Acequia, ID (426 E 200 N). A short presentation will be given in the office followed by a tour of the research plots.

The presentations will focus on cultural and chemical management of diseases. We will discuss strengths and weaknesses of different management approaches. We have been awarded 2 ISDA pesticide recertification credits and 2.5 CCA (Pest Management) credits for this meeting.

Lunch will be served. Please RSVP so that we can plan for the appropriate number of people. Additional information along with a detailed agenda can be found at the link below. There is no cost to attend.

» http://www.millerresearch.com/alerts/research-news/item/43-mr-pest-management-field-day

potato psyllid and ZC update

Potato All Locations

potato psyllids and ZC

Posted on: July 26, 2013 by Erik Wenninger

More potato psyllids were trapped this week in potato fields in Canyon, Ada, Elmore, Gooding, Jerome, and Twin Falls Counties. In addition, we trapped our first potato psyllids this week in Owyhee and Minidoka Counties. In addition to the counties listed above, in a previous week we had also captured a psyllid in Cassia County. All the psyllids tested from last week were negative for Lso, the bacterium that causes zebra chip. So far, over 100 potato psyllids have been collected this year in U-Idaho monitoring programs; of the 64 psyllids tested so far, only 3 have been positive for Lso (less than 5% incidence). In contrast, by this time last year roughly 50% of the psyllids collected were positive for Lso. It is important to note, however, that despite finding only a handful of Lso+ psyllids in the Columbian basin last year, zebra chip was still found.

Detailed monitoring results and management recommendations can always be found at the link provided below:

http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

» http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

potato psyllid and ZC update

Potato All Locations

potato psyllids and ZC

Posted on: July 19, 2013 by Erik Wenninger

More potato psyllids were trapped this week in potato fields in Ada, Canyon, Elmore, and Twin Falls counties. The number of psyllids collected per trap and per field remains relatively low; however, they are in line with trap counts from this time last year. It remains to be seen whether a similar increase will be observed this year, but last year’s sticky trap captures increased dramatically through August and September.

We are still waiting on results from Lso testing from psyllids collected during this and last week. Detailed monitoring results and management recommendations can always be found at the link provided below:

http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

» http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

Lso-positive potato psyllids found in Canyon and Twin Falls

Potato All Locations

potato psyllids and ZC

Posted on: July 16, 2013 by Erik Wenninger

For the first time this year we have found potato psyllids in Idaho that have tested positive for Lso, the bacterium that causes zebra chip. A total of three individual psyllids tested positive from early July: one in each of two fields in Canyon County and one collected at the Kimberly R&E Center.

Detailed monitoring results and management recommendations can always be found at the link provided below:

» http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

U-Idaho potato psyllid and ZC update

Potato All Locations

potato psyllids and ZC

Posted on: July 12, 2013 by Erik Wenninger

Potato psyllids were trapped this week on sticky cards in Canyon, Ada, Elmore, Twin Falls, and Cassia Counties. This was our first potato psyllid captured this year in Cassia County. So far no psyllids tested to date have been positive for the bacterium that causes ZC. We are still waiting on results from psyllids collected during this and last week. For detailed monitoring results and management recommendations, you can always use the link provided below:

http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

» http://extension.uidaho.edu/kimberly/2013/04/2013-psyllid-updates/

Potato All Locations

Posted on: June 28, 2013 by Jeff Miller

The 2013 Miller Research Potato Pest Management Field Day will be held August 14 beginning at 9:00 am at Miller Research in Rupert, ID (426 E 200 N). A brief presentation will be followed by the opportunity to tour the research trials and see the performance of various fungicide programs on early blight, white mold, Rhizoctonia and other potato diseases. We will be highlighting research that has been sponsored by the Idaho Potato Commission. We will conclude the tour around noon and lunch will be provided.

Please RSVP so that we can plan appropriately for the tour and for lunch. Contact Jeff Miller at 431-4420 or jeff@millerresearch.com.

potato psyllids found in Ada, Canyon, and Elmore Counties

Potato All Locations

potato psyllids and ZC

Posted on: June 21, 2013 by Erik Wenninger

--Results to date of sticky card captures from the ca. 90 fields being monitored with 4 yellow sticky cards can be found here: https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdHc2TVpneVJoeGk0ZDRIaHJQajhDVUE#gid=0

--1 potato psyllid was found in a field in Elmore County this week.

--Results to date of sampling from the 13 fields being monitored with yellow sticky cards, vacuum samples, and leaf samples can be found here: https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdFRNeW5ReDI2bTNWM0FwYmsxSnB1aGc#gid=0

--1 potato psyllid was found in a field in Ada County and a total of 3 potato psyllids was found across two fields in Canyon County this week.

--Any scouting programs underway for potato psyllids should be intensified, and IPM programs should be in place. Refer to the following site for guidance on scouting and IPM programs for potato psyllids: http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

Early blight found

Potato All Locations

Early Blight

Posted on: June 20, 2013 by Jeff Miller

A sample of early blight from Rangers being grown in the Hazelton area was found yesterday. Lesions were only observed on the lower, senescing leaves of the plant. This is early for this area. The most effective timing for fungicide application for early blight control is just before row closure.

A research report by Miller Research outlining the relative efficacy of different fungicide programs can be found at the link listed below.

» http://www.millerresearch.com/agricultural-research/agricultural-research-reports/potato-research-reports/early-blight-brown-spot/item/10-2012-earlyblight

One potato psyllid detected in Canyon County potato field

Potato All Locations

potato psyllids and ZC

Posted on: June 17, 2013 by Erik Wenninger

Among the approximately 90 fields are being monitored only with yellow sticky cards in cooperation with several crop consultants, one potato psyllid was found on a card in Canyon County last week. This psyllid will be tested for Lso, the bacterium that causes zebra chip.
Results to date of sticky card captures from the ca. 90 fields being monitored with yellow sticky cards can be found at the link below.

https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdHc2TVpneVJoeGk0ZDRIaHJQajhDVUE#gid=0

Weekly update summaries will be extended to stakeholders; however, to obtain the most up-to-date information on trap captures, this website can be checked at any time for periodic updates over the week.

A spreadsheet detailing results from the 13 fields being monitored using sticky cards, vacuum samples, and leaf samples will be posted soon. So far no psyllids have been detected from these sites.

More information and resources on potato psyllids and zebra chip can be found at the link below.

» https://docs.google.com/spreadsheet/ccc?key=0AuZRwfbNUs2YdHc2TVpneVJoeGk0ZDRIaHJQajhDVUE#gid=0

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

No potato psyllids detected in Idaho potatoes yet

Potato All Locations

potato psyllids and ZC

Posted on: June 14, 2013 by Erik Wenninger

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state initiated a scouting program during the week of May 13 that covers commercial potato fields throughout southern Idaho. The project is funded in part by ISDA and IPC. Thirteen fields are being monitored with 10 yellow sticky cards, vacuum samples, and leaf samples. Approximately 90 additional fields are being monitored with 4 yellow sticky cards. Thus far, no potato psyllids have been found in any samples from potato fields.

More information and resources on potato psyllids and zebra chip can be found at the link below.

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

No potato psyllids detected in Idaho potatoes so far

Potato All Locations

potato psyllids and ZC

Posted on: June 7, 2013 by Erik Wenninger

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state initiated a scouting program during the week of May 13 that covers commercial potato fields throughout southern Idaho. The project is funded in part by ISDA and IPC. Thirteen fields are being monitored with 10 yellow sticky cards, vacuum samples, and leaf samples. Approximately 90 additional fields are being monitored with 4 yellow sticky cards; scouting efforts in some fields (especially in eastern Idaho) are still being initiated. Thus far, no potato psyllids have been found in any samples from potato fields; however, this week one adult potato psyllid and numerous psyllid eggs were observed on bittersweet nightshade in Twin Falls. This is not surprising given the apparent ability of psyllids to overwinter in association with this alternative host plant. Next week we will provide access to an online spreadsheet that shows results of the potato field monitoring efforts and location of fields (by county).

More information and resources on potato psyllids and zebra chip can be found at the link below.

» http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/

2ee label for Vydate in potatoes

Potato All Locations

potato psyllid

Posted on: May 29, 2013 by Jerry Neufeld

Attached is the new Vydate®C-LV 2ee label from Dupont for suppression of Zebra Chip disease in potatoes. Click on the pdf below to view the label.

» 962_1.pdf

UI potato psyllid scouting program started

Potato All Locations

potato psyllids and ZC

Posted on: May 24, 2013 by Erik Wenninger

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state, has initiated a scouting program that covers commercial potato fields throughout southern Idaho. The project is funded in part by ISDA. The primary means of sampling psyllids will be by the use of yellow sticky cards, although vacuum samples and leaf samples are being taken from some fields as well. The first traps were deployed during the week of May 13; thus far, no potato psyllids have been found in any samples. Details of the monitoring program and results of monitoring efforts (by county) will be available soon.

colorado potato beetle

Potato Treasure Valley

colorado potato beetle

Posted on: May 13, 2013 by Jerry Neufeld

Colorado potato beetles were found in volunteer potatoes late last week in the Parma area. So far, only overwintered adults have been observed, and they will do little damage to potatoes. Scouting should begin soon for eggs and for larvae, which can cause considerable damage to commercial potatoes.

» CPB Adult

» CPB Eggs

» CPB Larvae

New potato information guides

Potato All Locations

Posted on: May 2, 2013 by Nora Olsen

The University of Idaho has recently published three potato related extension bulletins.

- 'Portable test kits for diagnosing potato disease' available at www.cals.uidaho.edu/edcomm/pdf/BUL/BUL0883.pdf
This bulletin highlights the use and accuracy of commercially available pathogen test kits for diagnosing disease in the field and storage. Multiple test kits for numerous diseases, such as PVY and Pythium, were used, assessed and compared to results from traditional diagnostic methods. Ease of test kit use and storage was also assessed and discussed. Overall, the test kits did a good job of accurately identifying the pathogen causing the problem, and in some cases, ruling out potential pathogens. They are relatively easy to use and can typically provide a result within 3 to 5 minutes. They are portable for use in the field, storage or office.

- 'Superficial growth on potatoes' available at www.cals.uidaho.edu/edcomm/pdf/CIS/CIS1191.pdf
This bulletin outlines factors that may promote superficial growth of non-pathogenic fungi and bacteria that can grow on the surface of a potato. Management practices to reduce the potential for superficial growth are also discussed.

- 'Storage Management of Blazer Russet Potatoes' available at www.cals.uidaho.edu/edcomm/pdf/CIS/CIS1192.pdf
This bulletin describes best storage management practices for 'Blazer Russet' released in 2005 by the USDA ARS and the agricultural experiment stations of Idaho, Oregon, and Washington. This is an early-maturing and high-yielding variety acceptable for fresh market or early season processing. This variety has acceptable fry color when stored at 48F and has a shorter dormancy length than Russet Burbank.

Potato psyllids found in the Magic Valley

Potato Magic Valley

potato psyllids and ZC

Posted on: April 12, 2013 by Erik Wenninger

Several natural or semi-natural areas near Twin Falls are being monitored during the winter for potato psyllids. Sites were selected near watercourses where the alternative host plant bitter nightshade is found. Thus far, no psyllids have been found in direct inspection of plants; however, two adult potato psyllids were found on a yellow sticky trap near Shoshone Falls in late March. Whether these psyllids overwintered or have migrated to our area is unknown. They will be tested for liberibacter, the bacterium that causes ZC, and monitoring efforts will continue through the season. More information on potato psyllids and ZC can be found below.

» http://www.kimberly.uidaho.edu/potatoes/

Positive Zebra Chip Infected Potatoes in Power County

Potato All Locations

Zebra Chip

Posted on: March 12, 2013 by Nora Olsen

A recent submission of potato tuber samples grown in Power County were verified to be positive for Lso (Candidatus Liberibacter solanacearum), the bacterium causing zebra chip in potatoes. Symptoms of zebra chip include necrotic flecking in the flesh of the tuber, similar to net necrosis, but the symptoms extend throughout the length of the tuber. When diseased tuber tissues are fried, severe darkening in both chips and fries are seen. Because symptoms can be seen in uncooked tissues, the disease is a concern for both fresh and process potatoes. The number one means to control zebra chip is to control infected potato psyllids. Non-infected psyllids will not cause zebra chip.

Please visit the following websites for additional information.

» http://www.kimberly.uidaho.edu/potatoes/

» http://zebrachipscri.tamu.edu/

Soil copper levels and potatoes

Potato All Locations

Copper toxicity

Posted on: January 11, 2013 by Jeff Miller

A new research article has been published discussing the impact of copper in soils as a result of dairy lagoon water treatment and the effect this can have on potato production. The article can be found at www.nwpotatoresearch.com and is published in the December 26, 2012 issue of Potato Progress (Volume 12, #19).

» www.nwpotatoresearch.com

» 929_1.pdf

University of Idaho Potato Conference

Potato All Locations

Posted on: December 17, 2012 by Nora Olsen

‘Education and Innovation’ is this year’s theme for the 45th annual University of Idaho Potato Conference and Eastern Idaho Ag Expo to be held January 22 to 24, 2013 in Pocatello, Idaho. The conference will have concurrent 1-hour sessions each day starting on Wednesday January 23rd at 8 am and ending January 24th at noon. Topics will vary and include all aspects of potato production and marketing. Zebra chip, bacterial ring rot and nematode management will be emphasized.

The conference will go back to its roots with basic potato and plant science education by offering a ‘Potato Science Course’ consisting of nine 1-hour sessions starting with Potato Crop Development and ending with Storage and Quality. You can attend one session to supplement your education on that particular topic, or all nine sessions for the complete course. These classes will be interactive and engaging for all participants, and will focus on the basic concepts needed to understand potato production.

Registration and a complete agenda are available at www.idahopotatoconference.com. Pre-register by January 11 for a reduced registration rate.

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: September 24, 2012 by Erik Wenninger

U-Idaho ZC and potato psyllid update – 21 Sep 2012

Potato psyllids continue to be trapped on yellow sticky cards across several sites being monitored by the University of Idaho in the Magic Valley. Of the remaining sites that have not undergone vine kill, numbers of adults were similar to or higher than during the previous three weeks. Nymphs and/or eggs were found at three sites in the Magic Valley; 44, 58, and 7 eggs per 100 leaf samples were found at sites 3, 4, and 5, respectively (see below), and 40, 23, and 0 nymphs per 100 leaf samples were found at sites 3, 4, and 5, respectively (see below). All but one site has now undergone vine kill. Only site 2 (in Jerome County) will be monitored next week. Reports of liberibacter incidence in samples will continue to be reported as the numbers come in. See the link below to view a table that details where (by county) and when potato psyllids and liberibacter have been found so far during this season in Idaho.

Tubers from the Kimberly R&E Center (site 7, below) were harvested today and will be evaluated for development of ZC symptoms over the storage season.
Refer to the sites below for guidance on scouting and IPM programs for potato psyllids and to view trap captures in Idaho so far over the season.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: September 14, 2012 by Erik Wenninger

U-Idaho ZC and potato psyllid update – 14 Sep 2012

Potato psyllids continue to be found on yellow sticky cards across several sites being monitored by the University of Idaho in the Magic Valley. For most sites, numbers of adults were similar to the previous two weeks. Nymphs continue to be found at two sites, and eggs were found on three sites; 1, 21, and 97 eggs were sampled from sites 2, 3, and 4, respectively, across 100 leaf samples at each site. Samples may be taken one more week on remaining Magic Valley sites before vine kill. No potato psyllids were found this week in the UI sampling network in western or eastern Idaho, and only one site (in Power County) will be sampled next week (vine kill has occurred on all other sites). A portion of the psyllids collected in previous weeks continues to test positive for liberibacter, the causal agent of ZC. See the link below to view a table that details where (by county) and when potato psyllids and liberibacter have been found so far during this season in Idaho.

Refer to the sites below for guidance on scouting and IPM programs for potato psyllids and to view trap captures in Idaho so far over the season.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: September 10, 2012 by Erik Wenninger

U-Idaho ZC and potato psyllid update – 7 Sep 2012

Potato psyllids continue to be found on yellow sticky cards across several sites being monitored by the University of Idaho. Two sites (one in Twin Falls County and one in Jerome County) continue to show high numbers relative to other sites and to earlier weeks. Numbers are also up slightly at the Kimberly R&E Center. Nymphs were found in larger numbers this week, particular at the site in Gooding County. Eggs also were found in larger numbers this week: 33, 2, 22, and 35 eggs were found among each of the 100 leaf samples taken from sites 1, 2, 3, and 4, respectively.

No potato psyllids were found this week in the UI sampling network in western or eastern Idaho. A portion of the psyllids collected in previous weeks continues to test positive for liberibacter, the causal agent of ZC. See the link below to view a table that details where (by county) and when potato psyllids and liberibacter have been found so far during this season in Idaho.

Vine kill will occur soon on most fields in the Magic Valley, so sampling will continue for no more than 1-2 weeks for most sites.

Refer to the sites below for guidance on scouting and IPM programs for potato psyllids and to view trap captures in Idaho so far over the season.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: August 31, 2012 by Erik Wenninger

U-Idaho ZC and potato psyllid update – 31 Aug 2012

Potato psyllids continue to be found on yellow sticky cards across several sites being monitored by the University of Idaho. Two sites (one in Twin Falls County and one in Jerome County) continue to show relatively high numbers compared to the previous week. For the first time this year, nymphs and eggs were found in UI-sampled fields (one nymph in each of two fields and six eggs in one of these fields). One potato psyllid was found in the UI sampling network in Canyon County this week (the second of the year; some psyllids had been found in this county by crop consultants over much of the summer). No potato psyllids have been found in eastern Idaho since the week of July 23. A portion of the psyllids collected in previous weeks continues to test positive for liberibacter, the causal agent of ZC. See the link below to view a table that details where (by county) and when potato psyllids and liberibacter have been found so far during this season in Idaho.

Continued scouting for psyllids and disease symptoms are strongly encouraged. Refer to the sites below for guidance on scouting and IPM programs for potato psyllids and to view trap captures in Idaho so far over the season.

Potato All Locations

Posted on: August 13, 2012 by Jeff Miller

This is a reminder for the Miller Research Pest Management Field Day which will be held Wednesday of this week from 9:30 to noon (please see the attached flier for more details). We have received two ISDA pesticide recertification credits for the meeting. Thank you to everyone who has replied. If you are planning on attending, but have not replied, please let us know ASAP for planning purposes. There is no cost to attend.

» Miller Research Field Day flier

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: August 10, 2012 by Erik Wenninger

U-Idaho ZC and potato psyllid update – 9 Aug 2012

Potato psyllids continue to be found across several sites being monitored by the University of Idaho. Numbers are similar to last week. Psyllids this week were only found on sticky cards at sites in the Magic Valley. We still have yet to find immature potato psyllids on leaf samples taken from potato fields. Of the psyllids found in previous weeks, a portion was positive for liberibacter, the causal agent of ZC. See the U-Idaho site below to view a table that details where (by county) and when potato psyllids have been found so far during this season in Idaho.

Plants with ZC symptoms have been collected or reported from several locations, but we are awaiting confirmation with PCR results. Thus far, zebra chip in potato plants has been confirmed by PCR (molecular testing) at three locations in Twin Falls County (including the Kimberly R&E Center) and one location in Minidoka County.

We continue to encourage vigorous scouting efforts. Refer to the sites below for guidance on scouting and IPM programs (including insecticide recommendations) for potato psyllids.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

» Aug 9 psyllids number table

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: August 3, 2012 by Erik Wenninger

U-Idaho ZC and potato psyllid update – 3 Aug 2012

Potato psyllids continue to be found across several sites being monitored by the University of Idaho. Numbers are up considerably at two sites. Sixteen potato psyllids were trapped on yellow sticky cards this week at the Kimberly R&E Center (and two psyllids were collected by vacuum sampling), and 54 potato psyllids were trapped on a grower’s field in Twin Falls County. Eight psyllids were trapped on sticky cards in a field in Jerome County, and one was trapped in another field in Twin Falls County. We have yet to find immature potato psyllids on leaf samples taken from potato fields. See the U-Idaho site below to view a table that details where (by county) and when potato psyllids have been found so far during this season in Idaho.

Thus far, zebra chip in potato plants has been confirmed by PCR (molecular testing) at three locations in Twin Falls County (including the Kimberly R&E Center) and one location in Minidoka County. Plants with ZC symptoms have been collected or reported from other locations, but we are awaiting confirmation with PCR results.

We continue to encourage vigorous scouting efforts. Refer to the sites below for guidance on scouting and IPM programs (including insecticide recommendations) for potato psyllids.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: July 31, 2012 by Erik Wenninger

University of Idaho potato psyllid scouting update – 31 July 2012

Potato psyllid captures were down slightly for the week of 23 July. We are reporting the first detection of potato psyllids in Gooding and Bonneville Counties, and the first report of liberibacter-positive psyllids in Canyon and Minidoka Counties this year.

From the University of Idaho sampling network, we collected the following from sticky cards last week: 1 psyllid from one site in Gooding County; 2 psyllids from one site in Minidoka County; 3 psyllids from one site in Bonneville County; 8 psyllids from one site in Jerome County; 9 psyllids from one site in Twin Falls County; and 2 psyllids from the Kimberly R&E center (in Twin Falls County).

Crop consultants and growers submitted the following on yellow sticky cards: 6 psyllids from 3 different sites in Elmore County; 3 psyllids from 2 sites in Canyon County; and 1 psyllid from a non-commercial site in Payette County.

From sticky card samples that were collected during the week of 16 July, 3 of 7 psyllids tested positive for liberibacter from one Twin Falls County site; 3 of 4 psyllids tested positive from another Twin Falls County site; 3 of 8 psyllids tested positive from the Kimberly R&E Center, and 2 of 6 psyllids tested positive from one Jerome County site. The one psyllid collected from a vacuum sample at a Twin Falls County site tested positive. In addition, psyllids on sticky cards (bulk sampled by location) submitted by crop consultants from fields in Minidoka, Elmore, and Canyon Counties tested positive for liberibacter.

The following is a brief summary of potato psyllid findings on sticky cards to date in Idaho:
University of Idaho sampling network:

Twin Falls County (3 sites, including Kimberly R&E Center) – adult psyllids (some positive for liberibacter); zebra chip infected plants confirmed (2 sites, including Kimberly R&E Center)

Jerome County (2 sites) – adult psyllids (some positive for liberibacter at one site only)

Minidoka County – adult psyllids (some positive for liberibacter)

Bonneville County – adult psyllids (awaiting results from liberibacter test)

Gooding County – adult psyllids (awaiting results from liberibacter test)

Other counties where scouting is occurring but no psyllids have been found: Madison, Bingham (2 sites) and Canyon (4 sites)

Samples submitted by crop consultants or growers:
Elmore County – adult psyllids (some positive for liberibacter)

Canyon County – adult psyllids (some positive for liberibacter)

Minidoka County – adult psyllids (positive for liberibacter)

No colonization of psyllids has been detected in scouted fields; i.e., we have yet to find any nymphs in fields. All psyllids have been adults trapped on yellow sticky cards, with the exception of 2 sites in Twin Falls County that were collected with a vacuum sampler. First detection of liberibacter-infected potato psyllids was June 19 in Twin Falls County. Plants and tubers with zebra chip symptoms (confirmed by molecular tests) were first detected July 17 in Twin Falls County. Additional samples have been submitted since that date and are awaiting confirmation.

We encourage everyone to increase scouting efforts. Ensure adequate insecticide treatment of the perimeter of fields, which may be missed by aerial application; psyllids are known to colonize fields first along the perimeter. Both potato psyllids and liberibacter are known to not be favored by very hot weather, but the role that weather has played in our findings to date or in disease epidemiology in general remains unclear.
Refer to the sites below for guidance on scouting and IPM programs for potato psyllids.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Potato Psyllids and Zebra Chip

Potato All Locations

Potato Psyllids and Zebra Chip

Posted on: July 22, 2012 by Erik Wenninger

The single potato plant observed on July 17 at the Kimberly R&E Center with zebra chip symptoms has tested positive for liberibacter, the bacterium that causes zebra chip. Several other plants with suspicious wilting symptoms were tested as well, and two of them also tested positive for liberibacter. Since these samples were taken, at least two additional plants were found at the Kimberly R&E Center with zebra chip symptoms; these also will be tested for liberibacter.

Also on July 17, several plants with suspicious symptoms from a grower field from which liberibacter-positive psyllids had been collected were tested for liberibacter. These plants all tested positive for liberibacter.

Two of the four psyllids collected from last week’s U-Idaho scouting program (week of July 9) tested positive for liberibacter. Both positive psyllids were in Twin Falls County; the psyllid found in Jerome County was negative.

The number of potato psyllids collected by our scouting program is now increasing, though numbers are still much smaller than what has been found in the Columbia basin. This past week, the U-Idaho sampling program collected potato psyllids from three grower fields (all in Twin Falls County) and from the Kimberly R&E Center. From the three grower fields, we collected 8, 6, and 4 potato psyllids, all but one of which was collected on yellow sticky cards (one was from a vacuum sample). We collected 8 psyllids at the Kimberly R&E Center.

Additionally, last week several potato psyllids were found on sticky cards taken into the Kimberly or Parma R&E Centers by crop consultants. Three potato psyllids were found across two potato fields in Canyon County, and on July 15 a single potato psyllid was collected from the Sand Hollow area of Canyon County from potatoes in a non-commercial setting. All samples will be sent to the University of Idaho campus to test for liberibacter.

We have now confirmed what is to our knowledge the first finding of ZC potato plants from this year’s planting in the Pacific Northwest this season. However, we continue to encourage scouting in order to make the most sound and appropriate management decisions for a given field.

Refer to the sites below for guidance on scouting and IPM programs for potato psyllids.

http://www.kimberly.uidaho.edu/potatoes/

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Plant with zebra chip symptoms found in Idaho

Potato All Locations

potato psyllid & zebra chip

Posted on: July 17, 2012 by Erik Wenninger

A single potato plant was observed on July 17 at the Kimberly R&E Center with classic zebra chip symptoms: aerial tubers, pink coloration on leaves, curling of leaves, and characteristic internal discoloration of tubers. Samples were sent to the University of Idaho campus to run molecular tests to confirm presence of liberibacter, the causal agent of zebra chip, but based on symptoms, we are reasonably confident that the plant is positive for zebra chip. The plant was pulled from the field and destroyed.

Additionally, psyllid samples collected on July 3 from two commercial fields in Twin Falls County have tested positive for liberibacter.

Samples for this week from other fields being scouted by the University of Idaho scouting program are still being collected and processed; we will have an update later on findings from these samples.

Two adult potato psyllids collected on yellow sticky traps from Elmore County on July 15 were taken into the Parma R&E Center. Two adult potato psyllids (one on July 13 and one on July 15) on yellow sticky traps from Minidoka County were taken into the Kimberly R&E Center. These samples will be sent to the University of Idaho campus to test for liberibacter.

To our knowledge, we have the first (preliminary) finding of a ZC potato plant from this year’s planting in the Pacific Northwest this season. However, we continue to encourage scouting in order to make the most sound and appropriate management decisions for a given field.

Refer to the sites below for guidance on scouting and IPM programs for potato psyllids.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Idaho potato psyllid update

Potato Magic Valley

potato psyllid

Posted on: July 13, 2012 by Erik Wenninger

A total of four adult potato psyllids was collected this week within U-Idaho’s potato psyllid sampling network throughout southern Idaho. One psyllid was collected on a yellow sticky trap from each of two grower fields in Twin Falls County. In addition, at the Kimberly Research & Extension Center, one psyllid was collected from a sticky trap and one was collected from a vacuum sample. These samples were sent to Moscow today to be tested for liberibacter. Obviously, numbers of psyllids continue to be rather low, and we still have yet to find potato psyllids of any life stage on potato plants themselves.

We continue to encourage scouting in order to make the most sound and appropriate management decisions for a given field.

Refer to the sites below for guidance on scouting and IPM programs for potato psyllids.

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

green peach aphid

Potato Treasure Valley - Oregon

green peach aphid

Posted on: July 10, 2012 by Jerry Neufeld

Dr. Clint Shock, Superintendent at the OSU Malheur Experiment Station is reporting that green peach aphid populations are spiking in Malheur County potato fields.

Zebra chip pathogen confirmed in Idaho, and more Lso-positiv

Potato Magic Valley

potato psyllid & zebra chip

Posted on: July 9, 2012 by Erik Wenninger

Updated 8 July 2012

The potato psyllid sample from June 19 in Twin Falls County that tested positive for liberibacter, the zebra chip pathogen, was confirmed to be positive by gene sequencing. Samples from the following week (one from the Kimberly R&E Center and one from the same grower’s field in Twin Falls County) also have tested positive for liberibacter by PCR.

A few more adult potato psyllids (collected on July 3) have been found on yellow sticky traps in two different commercial potato fields in Twin Falls County, Idaho. These samples should be tested for liberibacter this week. Numbers of psyllids continue to be rather low (1 and 3 psyllids per field), and we have yet to find potato psyllids of any life stage on potato plants themselves, suggesting that colonization of fields has not yet occurred.

Field bindweed found harboring potato psyllid eggs in a grower’s field last week tested negative for PCR, which is consistent with studies by USDA-ARS, Wapato suggesting that field bindweed is not a host to Liberibacter. More field bindweed with potato psyllids was found along edges of a potato field in Gooding County, ID. Both eggs and early instar nymphs were found. Although reported to not be a host for liberibacter, this weed is a suitable host for potato psyllids. The importance of field bindweed and other alternate weed hosts of potato psyllids (e.g., nightshades) in facilitating spread of psyllids into potato fields remains to be explored, but good weed management might aid in psyllid management in potato.
We continue to encourage scouting in order to make the most sound and appropriate management steps for a given field.

Refer to the following sites for guidance on scouting and IPM programs for potato psyllids:

http://www.kimberly.uidaho.edu/potatoes/

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

Zebra chip pathogen found in Idaho

Potato Magic Valley

potato psyllid & zebra chip

Posted on: July 2, 2012 by Erik Wenninger

Adult psyllids collected from a sticky card on a commercial field in Twin Falls County on June 19 have tentatively tested positive for Liberibacter, the bacterium that causes zebra chip. PCR tests conducted last week by Alex Karasev’s lab are being followed up this week by sequencing the bands to confirm that the sequences belong to Liberibacter. In the mean time, additional psyllids collected last week from this site and from the U-Idaho Kimberly R&E Center will be tested this week for Liberibacter.

We still have not found psyllids of any life stage on potato plants themselves. However, field bindweed was found along the edge of the field near the sticky card with “hot” psyllids, and today we found potato psyllid eggs (but no other life stages) on several field bindweed plants. The importance of this finding in relation to psyllid infestations in potato remains to be explored, but, considering potato psyllids have a broad host range that includes at least 20 plant families, weed management might aid in psyllid management in potato fields. The infested field bindweed also will be tested for Liberibacter.

This is the first (preliminary) finding of Liberibacter-infected psyllids in the Pacific Northwest this season; however, we still strongly recommend that fields be scouted in order to make the most sound and appropriate management steps for a given field.

Refer to the following sites for guidance on scouting and IPM programs for potato psyllids:

http://www.kimberly.uidaho.edu/potatoes/

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

» http://www.kimberly.uidaho.edu/potatoes/

» http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

More potato psyllids found in Idaho…

Potato Magic Valley

potato psyllid

Posted on: June 29, 2012 by Erik Wenninger

Updated 29 June 2012

Erik Wenninger, Nora Olsen, Phil Nolte, Mike Thornton, and Alex Karasev, in cooperation with Jeff Miller and Andy Jensen, are monitoring potato fields in Idaho for potato psyllids and Liberibacter, the bacterium that causes zebra chip (ZC). We found four adult potato psyllids on sticky cards that were collected on June 26 from a grower’s field in Twin Falls County. These were collected from the same site from which we collected two adult psyllids the previous week. We also found four adult potato psyllids on sticky cards that were collected on June 27 on bulk potatoes next to our insecticide trials at the Kimberly R&E Center. The samples are being shipped to campus to be tested for presence of Liberibacter. No potato psyllids were found this week at any of the other fields being monitored by our group in Idaho. Numbers of potato psyllids found are still low, and so far no immature potato psyllids have been found in leaf samples at any sites. We suggest that scouting programs in Idaho be intensified, and that IPM programs be ready. Samples can be taken to the Kimberly R&E Center for confirmation of potato psyllid identification. Refer to the following sites for guidance on scouting and IPM programs for potato psyllids:

http://potatoes.com/IPMStuff/PDFs/Idaho%20recommendations%20%202012%20final.pdf

http://www.potatoes.com/pdfs/PotatoPsyllid.pdf

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/30058/pnw633.pdf

More information on potato psyllids and zebra chip can be found here: http://www.kimberly.uidaho.edu/potatoes/

» http://potatoes.com/IPMStuff/PDFs/Idaho%20recommendations%20%202012%20final.pdf

» http://www.kimberly.uidaho.edu/potatoes/

First potato psyllids found in a commercial field in Idaho…

Potato Magic Valley

potato psyllid

Posted on: June 26, 2012 by Erik Wenninger

Erik Wenninger, Nora Olsen, Phil Nolte, Mike Thornton, and Alex Karasev, in cooperation with Jeff Miller and Andy Jensen, are monitoring potato fields in Idaho for potato psyllids and Liberibacter, the bacterium that causes zebra chip (ZC). We found two adult potato psyllids on sticky cards that were collected on 19 June from a grower’s field in Twin Falls County. This is the first potato psyllid finding we are aware of from a commercial potato field in Idaho during 2012. The samples are being shipped to campus today to be tested for presence of Liberibacter. No potato psyllids were found from last week at any of the other fields being monitored by our group in Idaho. Numbers of potato psyllids found were very low. We suggest that scouting programs in Idaho be intensified, and that IPM programs be ready. Refer to the following sites for guidance on scouting and IPM programs for potato psyllids:

http://potatoes.com/IPMStuff/PDFs/Idaho%20recommendations%20%202012%20final.pdf

http://www.potatoes.com/pdfs/PotatoPsyllid.pdf

More information on potato psyllids and zebra chip can be found here:
http://www.kimberly.uidaho.edu/potatoes/

» http://www.kimberly.uidaho.edu/potatoes/

» http://potatoes.com/IPMStuff/PDFs/Idaho%20recommendations%20%202012%20final.pdf

no potato psyllids in Idaho so far

Potato All Locations

potato psyllid

Posted on: June 22, 2012 by Erik Wenninger

No potato psyllids found on potatoes in Idaho so far...

Updated 22 June 2012

Erik Wenninger, Nora Olsen, Phil Nolte, Mike Thornton, and Alex Karasev, in cooperation from Jeff Miller and Andy Jensen, are monitoring potato fields in Idaho for potato psyllids and Liberibacter, the bacterium that causes zebra chip (ZC). We are still processing some of the samples collected this week, but so far no potato psyllids have been found in any of the fields we are monitoring in Idaho. More information on potato psyllids and zebra chip can be found here: http://www.kimberly.uidaho.edu/potatoes/

» http://www.kimberly.uidaho.edu/potatoes/

Updates on PNW Potato Psyllid and Zebra Chip

Potato All Locations

Potato Psyllid

Posted on: June 8, 2012 by Andy Jensen

Attached is Volume 12, Number 10 of the Potato Progress.

This issue answers a number of questions many of you have about zebra chip (ZC) and potato psyllid. In this issue: answers to several of the many good questions we received during the psyllid workshops held throughout the region, some information on psyllid overwintering, something about insecticide tests from WSPC-funded work in Texas, and some detailed information and photos to help with psyllid monitoring using yellow sticky cards (the latter will also be posted on the website, www.nwpotatoresearch.com).

» 880_1.pdf

Idaho Potato Psyllid Monitoring Update

Potato All Locations

Potato Psyllid

Posted on: June 7, 2012 by Erik Wenninger

No potato psyllids found on potatoes in Idaho so far…

Updated 7 June 2012

Erik Wenninger, Nora Olsen, Phil Nolte, Mike Thornton, and Alex Karasev, in cooperation from Jeff Miller and Andy Jensen, are monitoring potato fields in Idaho for potato psyllids and Liberibacter, the bacterium that causes zebra chip (ZC). This project, funded by the Idaho Potato Commission, includes a total of about 14 grower fields across the Treasure Valley, Magic Valley, and eastern Idaho. We began taking weekly samples during the week of May 21. Sampling efforts include yellow sticky traps (for adults), leaf samples (for nymphs), and vacuum samples (for adults; the vacuum sampler is a leaf blower with a vacuum attachment and a net to capture insects removed from potato foliage). So far no potato psyllids have been observed in any of our samples. We are only able to cover so much acreage in our sampling efforts, so we encourage all growers and crop consultants to conduct sampling as well. Photographs and key diagnostic characters of the different life stages of potato psyllids can be found at http://www.kimberly.uidaho.edu/potatoes/. You also may take samples to your local University of Idaho R & E Center to confirm identifications. We will continue to provide periodic updates of our monitoring efforts, and we will send out an immediate notification upon detection of any potato psyllids in potato. Potato psyllids also will be tested for presence of the ZC bacterium.

Idaho

Potato All Locations

Potato Psyllid

Posted on: May 14, 2012 by Nora Olsen

REMINDER

Idaho zebra chip (ZC) and potato psyllid workshops scheduled for this week.

To help industry prepare for psyllid monitoring and scouting, several training sessions have been scheduled. The workshops will have an open format, and we ask people to come any time that fits their schedule during each session. This will allow more personal attention and access to specimens and samples as people come and go. Dates, times, and locations for these sessions are:

May 15, 9:30 – noon, Parma Research and Extension Center, 29603 U of I Lane, Parma
May 16, 9:30 – noon, Miller Research LLC, 426 East 200 North, Rupert
May 17, 9:30 – noon, Idaho Falls R & E Center, 1776 Science Center Dr.

Colorado Potato Beetle

Potato Treasure Valley - Idaho

Colorado Potato Beetle

Posted on: May 11, 2012 by Jerry Neufeld

The following information was provided by Dr. Mike Thornton, Potato Specialist at the UI Parma R and E Center.

“The mild winter means that plenty of volunteer plants are starting to emerge in fields that were in potatoes last year. These volunteers can allow many potato disease and insect problems to get started before moving into nearby commercial fields. Specifically, I have seen a few adult Colorado potato beetles (CPB) feeding on emerged volunteers. These adults don’t usually cause a lot of damage, but will be laying eggs very soon. The first generation of CPB that hatches from these eggs can be very damaging in fields that have not been treated with a systemic insecticide at planting, and these fields should be scouted after emergence.”

Webcast on Internal Heat Necrosis

Potato All Locations

Internal Heat Necrosis

Posted on: May 1, 2012 by Jeff Miller

Internal Heat Necrosis of Potato Featured in Latest Focus on Potato Webcast

Internal Heat Necrosis, or IHN, has many aliases. They include internal brown spot, physiological internal necrosis, internal browning, internal brown fleck, and chocolate spot.

Whatever you choose to call this physiological disorder, it is an economically significant problem, particularly in the mid-Atlantic and southern United States. It is also the latest topic addressed in Focus on Potato, the Plant Management Network's nonprofit webcast resource for potato growers and consultants.

In this talk, Dr. Craig Yencho, Professor in the Department of Horticulture at North Carolina State University, covers various aspects of IHN including symptoms and control, when a crop is at risk of developing IHN, models to predict the occurrence of IHN, varietal resistance to IHN, and current research efforts to develop IHN resistant potato varieties.

This presentation is open access through June 30, 2012 and can be viewed at the link listed below. Users can view other recent webcasts in the Focus on Potato resource with a paid subscription.

Focus on Potato is a publication of the Plant Management Network (PMN), a nonprofit online publisher whose mission is to enhance the health, management, and production of agricultural and horticultural crops. It achieves this mission through applied, science-based resources. PMN is jointly managed by the American Society of Agronomy, American Phytopathological Society, and Crop Science Society of America.

» http://www.plantmanagementnetwork.org/edcenter/seminars/potato/HeatNecrosis/

» http://www.plantmanagementnetwork.org/fop

Webcast on potato sugar management

Potato All Locations

Sugar management

Posted on: April 6, 2012 by Jeff Miller

A new webcast is available through Focus on Potato on sugar management. The webcast will be freely available through May 31. The webcast can be viewed at the link below.

From Focus on Potato:
Sugar management is an important factor for potato crops. In this month's Focus on Potato presentation, titled "Sugar Management in Storage," Dr. A.J. Bussan from the University of Wisconsin guides viewers through sugar management of tubers during various stages of crop management and storage. This talk offers guidance on in-season practices, best practices and timing during potato harvest, preconditioning in storage and storage management.

» http://www.plantmanagementnetwork.org/edcenter/seminars/potato/sugarmanagement/

Psyllid identification workshops

Potato All Locations

Potato psyllid/zebra chip

Posted on: March 30, 2012 by Jeff Miller

Zebra chip (ZC) and potato psyllid are on a lot of your minds this spring. To help industry
prepare for psyllid monitoring and scouting, several training sessions have been scheduled. The
workshops will have an open format, and we ask people to come any time that fits their schedule during
each session. This will allow more personal attention and access to specimens and samples as people
come and go. Dates, times, and locations for these sessions are:

Washington
May 1, 1:30 – 4 pm, Moses Lake, Potato Commission office, 108 S Interlake Rd.
May 2, 9:30 – noon, Pasco, Franklin County Extension office, 404 W. Clark Ave.

Idaho
May 15, 9:30 – noon, Parma Research and Extension Center, 29603 U of I Lane, Parma
May 16, 9:30 – noon, Miller Research LLC, 426 East 200 North, Rupert
May 17, 9:30 – noon, Idaho Falls R & E Center, 1776 Science Center Dr.

Oregon
April 17, 9:00 – 10:00 am, Hermiston Ag. Research and Extension Center, 2121 South First Street
May 1, 9:00 – 10:00 am, Hermiston Ag. Research and Extension Center, 2121 South First Street

Potato psyllid management recommendations for 2012

Potato All Locations

Potato psyllid/ZC

Posted on: March 20, 2012 by Jeff Miller

With the detection of Zebra Chip in 2011, many people have questions about managing potato psyllids and Zebra Chip in 2012. Attached are three documents aimed at providing the most accurate information available for our situation in Idaho:

1. Idaho recommendations (drafted by Phil Nolte, Erik Wenninger, Mike Thornton, and Nora Olsen of the University of Idaho; Jeff Miller of Miller Research; and Andy Jensen of the ID/WA/OR Potato Commissions)

2. Biology and Management of Potato Psyllid in Pacific Northwest Potatoes by Alan Schreiber (Agriculture Development Group, Inc.), Andy Jensen (ID/WA/OR Potato Commissions), and Silvia Rondon (Oregon State University).

3. Psyllid Identification/Information Card

Please contact us (Phil Nolte, Erik Wenninger, Mike Thornton, Nora Olsen, of the University of Idaho; Jeff Miller of Miller Research; or Andy Jensen of the ID/WA/OR Potato Commissions) if you have any questions or comments regarding the plan. This information also will be posted at multiple websites as indicated in the recommendation plan.

» Zebra Chip Recommendations 2012

» 856_2.pdf

» 856_3.pdf

potato pysllid

Potato All Locations

potato psyllid

Posted on: February 23, 2012 by Jerry Neufeld

Click on the pdf below to learn more about the potato psyllid in the "Potato Progress." The publication is entitled "Biology and Management of Potato Psyllid in PNW Potatoes.

» 853_1.pdf

Pest Management Workshop

Potato All Locations

Posted on: November 15, 2011 by Jeff Miller

Miller Research LLC will be holding its annual pest management research meeting on Wednesday, December 7. The meetings will be held at the Miller Research facility located near Acequia, ID. (426 E 200 N) Presentations will discuss chemical and cultural practices to manage crop diseases. The focus of the meeting will be on potato diseases, but we will be sponsoring a presentation on managing stripe rust in small grains due to the timeliness of the subject.

9:00-10:00: Managing foliar diseases of potato (early blight, brown leaf spot, white mold, gray mold, late blight, and black dot) – Dr. Terry Miller and Trent Taysom, Miller Research

10:00-11:00: Managing soil-borne diseases of potato (Rhizoctonia, silver scurf, pink rot, black dot) – Dr. Jeff Miller, Miller Research

11:00-11:30: Managing Zebra Chip in potato – Dr. Nora Olsen, University of Idaho

11:30-12:00: Managing stripe rust in small grains – Dr. Juliet Marshall, University of Idaho

» Miller Research Pest Management Workshop

Confirmation of Zebra Chip in Idaho

Potato All Locations

Zebra Chip

Posted on: October 10, 2011 by University of Idaho

On October 7, 2011 an announcement was made regarding a new potato disease found in Idaho. It is called Zebra Chip. This disease is caused by a bacterium (Liberibacter) that is transmitted by Potato Psyllids. This disease has been around for numerous years, traditionally plaguing southern US potato fields. In September it was found in the Columbia Basin of OR and WA and has now been confirmed in Idaho. Although research has been done over the last several years there is still a lot we do not know about this disease and psyllid movement.

Tuber samples of several varieties were collected in Jerome and Twin Falls counties during the last two weeks. Please see the photos in the attachment for reference. Zebra Chip causes necrotic flecking in the flesh of the tuber similar to net necrosis but the symptoms extends throughout the length of the tuber. When diseased tuber tissues are fried the disease causes severe darkening in both chips and fries. Because symptoms can be seen in uncooked tissues, the disease is a concern for both fresh and process potatoes. One interesting thing to note is that typically infected tubers will not sprout.

Samples may be submitted to the University of Idaho for verification. Samples can be taken to your county extension office or taken directly to Phil Nolte (Idaho Falls R & E Center, 208-529-8376), Mike Thornton (Parma R & E Center, 208-722-6701) or Nora Olsen (Twin Falls R & E Center, 208-736-3600). We can either confirm it from visual symptoms or will send it off for verification. Please note the county and variety with the sample. No need to keep samples cool now that the weather has changed but do keep them from freezing. Place cut tuber in a plastic bag with insulation around it and fed ex to one of us. Avoid sending on Friday since the sample may be left out unprotected. Questions can be directed to Phil Nolte at the above number.

We will keep you posted on the progress of this disease in Idaho. The good news is that of the fields identified as infected to date, the incidence of infected tubers has been extremely low. We should also note that potato psyllids are not known to overwinter in the northern US, so their presence may be a transient problem related to the unusual weather pattern during 2011. We are all currently on a steep learning curve and need to work together to identify the scope of this problem and the best way to manage it.

Additional information can be found at http://agrilife.org/zebrachip/

Phil Nolte, Mike Thornton and Nora Olsen, University of Idaho.

» 831_1.pdf

Late blight on home garden tomatoes

Potato All Locations

Late blight (tomato)

Posted on: September 22, 2011 by Jeff Miller

Late blight has recently been confirmed on tomato plants from a home garden in Preston, ID. This late in the season, the occurrence is not a threat to potato production. Work is being done to determine if this occurrence is related to the potato late blight that was found nearby in Utah, or if this was an independent occurrence. This finding emphasizes the importance of watching tomatoes as a potential source for late blight.

Late blight found in northern Utah

Potato All Locations

Late blight

Posted on: September 2, 2011 by Jeff Miller

Late blight has been confirmed by the University of Idaho in a potato field in northern Utah. It appears the disease has been present for at least two weeks, but spread has been limited due to dry weather conditions.

It is highly unlikely that this field would pose a threat to Idaho potatoes. However, this confirmed outbreak illustrates that late blight could be present in other fields in our state. Growers with fields that are still green and weeks away from vine kill need to be sure that the foliage is protected. A standard protectant such as chlorothalonil or EBDC will be effective in doing this.

Miller Research Potato Pest Management Field Day

Potato All Locations

Posted on: August 8, 2011 by Jeff Miller

Miller Research will be holding a potato pest management field day on Monday, August 15 at the Miller Research facility located near Acequia, ID (426 E 200 N). A short presentation will be given in the office followed by a tour of the research plots sponsored by the Idaho Potato Commission. Lunch will be provided. There is no cost to attend.

The tour will highlight new research on early blight, white mold, black dot, Rhizoctonia, and pink rot. Two ISDA recertification credits and 2 CCA (pest management) credits have been awarded for this meeting. Please RSVP to Jeff Miller at 208-531-5124 or by email at jeff@millerresearch.com so that we can get an accurate count for room preparation purposes.

Green peach aphids in potato

Potato Magic Valley

Green peach aphid

Posted on: July 22, 2011 by Jeff Miller

Green peach aphids have been found in potatoes in the Rupert/Burley area. See the PNW Pestalert posting on July 16 for more information on aphid management.

Green Peach Aphid

Potato Magic Valley

Aphids in Potatoes

Posted on: July 16, 2011 by Tony McCammon

Green peach aphids were observed in Kimberly this week. Aphids on potato are of concern only in regard to their transmission of plant viruses. Systemic insecticides are generally the most effective against aphids; however, use of insecticides may reduce, but will not eliminate spread of viruses. There are no well-established treatment thresholds for aphids in potato. Consult the PNW Insect Management Handbook (http://pnwpest.org/pnw/insects) for registered products. Consult CIS 1165 (http://www.cals.uidaho.edu/edComm/detail.asp?IDnum=1535) by Nolte, Alvarez, and Whitworth for more detailed recommendations on management of aphid vectors of potato virus, including insecticide recommendations.

Early blight

Potato Magic Valley

Early blight

Posted on: July 15, 2011 by Jeff Miller

Early blight lesions have been found on the lower leaves of both Russet Burbank and Western Russet. Fungicide applications for early blight/brown leaf spot control should be made at this time if they have not already been initiated.

Several products are effective for control of early blight such as Endura, QoIs (Gem, Tanos, Headline, Quadris, Reason), and products with difenoconazole (Revus Top, Quadris Top, and Omega Top). These products should be tank-mixed with a standard protectant such as a chlorothalonil or EBDC product. Reduced sensitivity has been found with Endura, Quadris, and Headline in the early blight pathogen population. In a trial sponsored by the Idaho Potato Commission and industry in 2010 Gem and Tanos showed greater disease control than Headline and Quadris. We believe all these products are still useful and provide value, but should be used with a protectant.

The standard protectant (chlorothalonil or EBDC) will provide good protection against late blight. In our semiarid environment, the standard protectants have resulted in very good late blight control when applied before an outbreak has occurred. Our research has shown that repeated use of the same protectant will build fungicide residue in the potato canopy. (Standard protectants have a broad spectrum of activity and the risk of resistance developing due to repeated use is very low.) Endura is not effective against late blight, and most QoI products need to be applied at higher rates (relative to early blight) to provide late blight protection. Revus Top and Tanos both have active ingredients effective against late blight. Gavel is also very effective against late blight and has an EBDC component to provide protection against early blight. A more detailed discussion of different fungicides effective against late blight can be found at the link below.

Applications should be made on a 10-14 day schedule during this time of rapid vine growth. Recent thundershowers have also made the environment favorable for both early and late blight development.

We have published a discussion of products, application methods, and application intervals at the link provided below.

» http://www.millerresearch.com/reports/LateBlight/Overview_of_Fungicides_for_Late_Blight.pdf

Late blight in potato

Potato All Locations

Phytophthora infestans

Posted on: June 29, 2011 by Jeff Miller

Late blight has been found in the Columbia Basin and is present in four fields north of the Tri-Cities.

It is recommended that all growers prepare for late blight due to the favorable weather conditions experienced this spring and the presence of late blight in many seed areas this past year. A summary of fungicides that are effective against late blight can be found at the link below.

If you find any suspicious samples, please send them to University of Idaho extension personnel or to us here at Miller Research. Even if you know you have found late blight, we would like samples in order to determine the genetic strain. This will better help us understand where the late blight originated. All submissions will be held confidential and reported only on a county basis.

» http://www.millerresearch.com/reports/LateBlight/Overview_of_Fungicides_for_Late_Blight.pdf

Colorado Potato Beetle

Potato Magic Valley

Colorado Potato Beetle

Posted on: June 14, 2011 by Jerry Neufeld

Dr. Erik Wenninger, Extension Entomology Specialist with UI-CALS in Kimberly is reporting that Colorado potato beetles were observed in Kimberly late last week. So far, only overwintered adults have been observed, and they will do little damage to potatoes. Scouting should begin soon for eggs and for larvae, which can cause considerable damage.

To guard against development of insecticide resistance, post-emergence applications of neonicotinoid insecticides should not be used if a neonicotinoid seed treatment or other at-planting neonicotinoid treatment was used. Examples of neonicotinoid seed or at-planting treatments include Admire, Belay, Cruiser, Gaucho, and Platinum. Examples of foliar neonicotinoid sprays include Actara, Belay, Endigo ZC, Leverage, and Provado.

Those using “soft” chemistries against Colorado potato beetles should be especially vigilant about scouting to appropriately time sprays. Sprays against the first generation should be applied when the first mature larvae are seen; at this time most of the larvae have hatched, but are still relatively small and susceptible to insecticides.

Border sprays may be considered if populations have not spread into the interior of fields.

Updated USDA GAP Audit

Potato All Locations

Posted on: June 9, 2011 by Nora Olsen

Please note an updated USDA Good Agricultural Practices (GAP)Good Handling Practices (GHP)Audit Verification Checklist is now available. This latest version was effective June 6, 2011. Visit the USDA website to view the newest version:

http://www.ams.usda.gov/gapghp

The University of Idaho will update their GAP organizational manual to coincide with the latest GAP Audit version. Visit www.kimberly.uidaho.edu/potatoes/gap.htm in the future to download the updated manual.

Only minor changes were made to the audit but these changes will need to be addressed in all future farm and storage audit visits.

Colorado Potato Beetle

Potato Treasure Valley - Idaho

Colorado Potato Beetle

Posted on: June 2, 2011 by Jerry Neufeld

Bill Buhrig from the UI, Parma Research and Extension Center, is reporting that overwintering Colorado Potato Beetle adults are beginning to emerge in southwest Idaho. This overwintering adult stage does not do much damage; however, females are beginning to lay eggs in potato fields. We could see the damaging larvae appear in about 7 to 10 days depending on temperatures. This is the time for growers to be scouting for CPB, especially if they are using "soft" foliar insecticides that target control of early instar larvae.

Webcast in potato irrigation

Potato All Locations

Posted on: March 1, 2011 by Jeff Miller

A new webcast is available through the Focus on Potato website (www.plantmanagementnetwork.org/fop). While much of the content is only available through a paid subscription, new webcasts (such as the one described below) are available for viewing at no cost for a period of time. The following webcast is available for no charge through April 30. If you have any questions or feedback, please feel free to contact me (Jeff Miller, 531-5124 or jeff@millerresearch.com).

"Avoid Crop Water Stress, Produce Higher Yielding, Quality Potatoes through Latest Focus on Potato Webcast"

Careful irrigation is required to avoid crop water stress and produce high-yielding, high quality potatoes.

To help growers and consultants achieve this end, Focus on Potato, a crop science resource for growers and consultants in the potato industry, has published its latest webcast, titled “Early Season Irrigation Management of Potato.”

This 56-minute presentation, authored by Howard Neibling, Professor of Biological and Agricultural Engineering at the University of Idaho, explains a method of pre-season irrigation planning to evaluate the adequacy of irrigation system capacity under the viewer's specific climate and soil conditions for normal and unusually high water-use years.

And for marginal or inadequate systems, suggestions are given for pre-season equipment changes and water management strategies to produce a high yield and quality potato crop.

View this presentation at http://www.plantmanagementnetwork.org/edcenter/seminars/potato/Irrigation_EarlySeason/

Other presentations are available on the Focus on Potato website at www.plantmanagementnetwork.org/fop.

Focus on Potato is a publication of the Plant Management Network (www.plantmanagementnetwork.org), a nonprofit online publisher whose mission is to enhance the health, management, and production of agricultural and horticultural crops. It achieves this mission through its applied, science-based resources. PMN is jointly managed by the American Society of Agronomy, American Phytopathological Society, and Crop Science Society of America.

» http://www.plantmanagementnetwork.org/edcenter/seminars/potato/Irrigation_EarlySeason/

» www.plantmanagementnetwork.org/fop

Miller Research Potato Pest Management Workshop

Potato All Locations

Posted on: January 28, 2011 by Jeff Miller

Miller Research LLC will be holding its annual potato pest management research meeting on Tuesday, February 15 and Wednesday, February 16. The same program will be presented both days. The meetings will be held at the new Miller Research facility located near Acequia, ID (426 E 200 N). Presentations will discuss chemical and cultural practices to manage diseases and nematode pests.

There is no cost to attend this meeting. A total of 3 CCA (pest management) and 3 ISDA recertification credits are available. If you have question or concerns you would like addressed please submit them by e-mail. If you know of other interested parties please forward this notice.

The meetings will begin at 8:30 and conclude at noon.

8:30 White mold control
9:00 Managing early blight and brown leaf spot
9:30 Late blight expectations for 2011
10:00 Break
10:15 Managing nematodes in potato (Dr. Saad Hafez)
11:00 Fungicides for pink rot management
11:30 Rhizoctonia and Fusarium dry rot management

Potato All Locations

GAP Audit

Posted on: April 2, 2010 by Nora Olsen

The University of Idaho has updated the previously available Potato GAP Audit Organizational Manual. The UI manual is designed to simplify the collection of information necessary to pass the USDA GAP Audit and is now available for download at the UI Kimberly R&E Potato Storage website: http://www.kimberly.uidaho.edu/potatoes/gap.htm.

In November of 2009 the USDA replaced the May 11, 2007 version of their Good Agricultural Practices (GAP) & Good Handling Practices (GHP) Audit Verification Checklist. The new version has three major changes: 1) new identification of records, policy or documentation requirements, 2) new numbering, wording or point values for previously asked questions, and 3) the addition of new questions and traceability questions were added to each section. The updated UI GAP Audit Organizational Manual incorporated these changes into the newest version and this manual will be useful in preparing for the 2010 GAP Audit.

Updated version of USDA GAP Audit

Potato All Locations

Posted on: November 18, 2009 by Nora Olsen

The USDA updated the Good Agricultural Practices (GAP) and Good Handling Practices (GHP) Audit Verification Checklist on November 9, 2009.

See www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELPRDC5050869 to view the latest version of the audit. (Cut and paste the link into your browser.)

There are substantial changes to the audit that will be necessary to incorporate into your on-farm food safety program. All current University of Idaho GAP Organizational Manuals are no longer valid and updates will be required. These updates are currently under construction and will be posted at www.kimberly.uidaho.edu/potatoes/gap.htm

Other manuals or paperwork you use will need to be updated to include documentation to address the latest version of the GAP Audit.

Late blight found in southern Idaho

Potato All Locations

Posted on: September 1, 2009 by

Late blight has been confirmed in multiple fields in southern Idaho. The late blight is not severe and with the current weather the threat of spread is low. The source of the late blight is not known at this time.

The late blight forecast was positive for all of southern Idaho this year. Last year it is likely that late blight was more wide-spread than was reported based on suspected late blight tubers in storage. Fields with healthy, green vines should be scouted thoroughly. Scouting should be concentrated in areas of the field that remain wet the longest, such as the center tower of pivots, along mainlines, in low-lying areas, and near windbreaks and shaded areas.

Ranger Russet tubers are especially susceptible to infection, so fungicide applications may be necessary especially if the vines will not be killed for a few more weeks. Use fungicides labeled for late blight. Some early blight fungicides (such as Endura) are not effective against late blight. If late blight is confirmed in a field and the tubers are destined for long term storage, tubers can be treated with phosphorous acid to decrease the risk of storage rot.

Late blight NOT confirmed at this time

Potato All Locations

Posted on: June 30, 2009 by Jeff Miller

Late blight has NOT been confirmed at this time in southern Idaho. Samples that were submitted for identification turned out to be gray mold (caused by Botrytis). At this time, rumors of late blight in Elmore County and in the Rupert/Burley area have not been confirmed.

The weather has been favorable for late blight development, however, and it is recommended that any suspicious lesions be evaluated by trained personnel.

Late blight forecast for southern Idaho for 2009

Potato All Locations

Posted on: June 12, 2009 by Jeff Miller

Our cool, wet spring has created an environment favorable for the development of late blight. A prediction model developed at the University of Idaho by Henderson et al. indicates that the likelihood of late blight development is relatively high. The forecast value is highest in the Fort Hall area and lowest in Parma. The actual occurrence of late blight and the date of first appearance will be affected by subsequent weather and fungicide application patterns.

The forecast in 2008 was also relatively high early in the season, but hot, dry weather was likely responsible for the limited development of late blight. It is critical to scout fields. Any area of the field where plant leaves and stems stay wet for extended periods of time (e.g. near the center points of pivots, irrigation overlaps, along mainlines, near windbreaks) should be scouted intensely. The use of a protectant fungicide is recommended prior to row closure.

A full discussion of different fungicides labeled for late blight control, along with information on application method and frequency is attached here and also available at:

http://www.millerresearch.com/reports/Overview_of_Fungicides_for_Late_Blight.pdf

» Fungicide for late blight control

Early blight resistance management

Potato All Locations

Posted on: June 11, 2009 by William H. Bohl

Early blight, caused by Alternaria solani, is a very common disease of potato found in most potato-growing areas in Idaho. Although it occurs annually to some degree in most production areas, the timing of its appearance and the rate of disease progress help determine the impact on the potato crop. Though losses rarely exceed 20 percent, if left uncontrolled, the disease can be very destructive. Since 1999, the persistent and intensive use of azoxystrobin and other QoI fungicides alternated with chlorothalonil on commercially grown potato crops in the Midwest and throughout the United States have increased the selection pressure for the development of QoI fungicide resistance in A. solani.

Learn more about what this may mean to you in the June Spudvine newsletter from University of Idaho http://extension.ag.uidaho.edu/bingham/Jun%202009.pdf

Colorado Potato Beetles in Magic Valley

Potato Magic Valley

Posted on: June 1, 2009 by Nora Olsen and Jeff Miller

Overwintering Colorado Potato Beetle adults are beginning to emerge in southcentral Idaho-- both Eastern and Western Magic Valley. Confirmed areas include Rupert, Minidoka, and Twin Falls.

The overwintering adult stage does limited damage, however, females are beginning to lay eggs in potato fields. We could see the damaging larvae appear in about 7 to 10 days depending on temperatures. Growers that did not apply an effective systemic insecticide at planting should be watching for the egg hatch to time a foliar spray for the first generation of CPB larvae.

Colorado Potato Beetle

Potato Treasure Valley - Idaho

Posted on: June 1, 2009 by Jerry Neufeld

Dr. Mike Thornton, from the UI Parma Research and Extension Center, is reporting that overwintering Colorado Potato Beetle adults are beginning to emerge in southwest Idaho. This overwintering adult stage does not do any damage, however, females are beginning to lay eggs in potato fields. We could see the damaging larvae appear in about 7 to 10 days depending on temperatures. Growers that did not apply an effective systemic insecticide at planting should be watching for the egg hatch to time a foliar spray for the first generation of CPB larvae.

» Colorado Potato Beetle Adult

» CPB eggs

» CPB Larvae

2009 Idaho Potato Conference

Potato All Locations

Posted on: September 8, 2008 by Nora Olsen

Mark your calendars!

Initial plans are being made for the 2009 Idaho Potato Conference in Pocatello, ID on Jan 21-22, 2009.

Please help us provide the most pertinent information by suggesting topics and speakers for the conference.

You can either contact me directly (208-736-3621)or use the attached form that can be faxed (208-736-0843)or emailed (norao@uidaho.edu) to me. Or feel free to pass along your suggestions without the form.

We look forward to receiving your input and seeing you at 2009 Idaho Potato Conference.

Nora Olsen
2009 Conference Chair

» Potato Conference Suggestions

Organic Potato Field Days

Potato All Locations

Posted on: August 29, 2008 by Nora Olsen

Mark your calendars for Organic Potato Field Days on Thursday September 18th in Idaho Falls from 1 to 3 pm and Friday September 19th in Shoshone from 10 am to noon. The Field Days will highlight organic potato growers, provide University of Idaho research on organic production, and offer insight to organic production by Alec McErlich who is an agricultural research and development manager for Small Planet Foods.

To get directions and to RSVP contact Keith Esplin at 208-243-1824 or pgike@cableone.net.

Late blight in Cassia County

Potato All Locations

Posted on: August 27, 2008 by Jeff Miller

Late blight was confirmed today in three separate fields in Cassia County. In all fields the blight was not severe and was limited in distribution. It is critical to scout fields that are still green and growing. Fungicide sprays are recommended if late blight is found in or near a field with healthy plants. These finds indicate that the disease is more widespread that previously thought.

Potato Pink Rot Survey

Potato All Locations

Posted on: August 26, 2008 by Jeff Miller

Miller Research is conducting a survey to determine the extent of mefenoxam (e.g. Ridomil) sensitivity to the pink rot pathogen in potato. If you find pink rot in a potato field and are willing to participate in the survey, please contact Jeff or Terry Miller at (208) 531-5124. We will provide instructions on sampling. Results from specific fields will remain confidential, but an overall summary will be reported for each county.

» Pink rot symptoms in potato

Late blight in Minidoka County

Potato All Locations

Posted on: August 20, 2008 by Jeff Miller

Late blight has been confirmed in two more fields in Minidoka County. One was a few miles north of Paul and the other near Norland. The location of these fields indicates that the pathogen has been spread over a larger area than first estimated.

It is critical to continue fungicide applications as long as vines are green. Gavel, Omega, Revus Top, and Tanos are good stand alone products for foliar late blight control. Revus Top and Tanos are also effective against early blight. Gavel has some EBDC premixed with the product. Curzate, Forum, and Previcur and can be mixed with a standard protectant such as chlorothalonil or an EBDC to provide greater protection than using chlorothalonil or an EBDC alone. Strobilurin products such as Headline, Quadris, and Reason are similar to standard protectants when used at the early blight rate and the higher end of the rate range should be used for late blight protection.

Late blight in Minidoka County

Potato All Locations

Posted on: August 14, 2008 by Jeff Miller

Late blight was found in two more potato fields in Minidoka County today, bringing the total number of confirmed fields to three. These two fields are located a couple of miles north of Paul and both are north of the first confirmed field. The disease pattern in these fields is consistent with spread from another source. It is likely that thundershowers last week spread the pathogen and it is possible that other fields in the area have been affected. It is essential that fields be scouted and any suspicious lesions be analyzed by trained personnel.

These additional findings underscore the importance of reporting late blight. An accurate knowledge of disease incidence is essential so all growers can know how often to apply fungicides. Please report any potential late blight findings so that accurate alerts can be posted.

These finds also show that late blight can get started inside the potato canopy even when overall weather conditions have not been favorable for disease development. Fields with actively growing plants in the Rupert and Paul area should be treated weekly with protectant fungicides such chlorothalonil or EBDC. Other fungicides with greater efficacy can be either tank-mixed with protectants or used in place of protectants.

If you have questions or concerns please contact Jeff Miller at 208-431-4420.

Late blight in southern Idaho

Potato All Locations

Posted on: August 4, 2008 by Jeff Miller

Late blight was confirmed today in the Mini-Cassia area. The disease pattern is consistent with a seed-borne source of the pathogen. The field in question had received fungicide applications and lesions could not be found in any adjacent fields. The field is scheduled to be killed today. Based on this fact and the absence of thundershowers, the probability of field to field spread is very low. If growers have been applying fungicides with activity against late blight then additional applications are not needed. Fungicides active against late blight include (but are not limited to) standard protectants (chlorothalonil and EBDC based products), strobilurins, Omega, and Gavel. Endura is not effective against late blight.

This finding underscores the importance of buying clean seed and scouting. Even though the weather has not been favorable for late blight development, the disease can get started inside a potato canopy if inoculum is present.

If you have questions or concerns please contact Jeff Miller at 208-431-4420.

» Late blight, top of leaf

» Late blight, underside of leaf

Colorado potato beetle larvae

Potato Magic Valley

Posted on: June 30, 2008 by Jeff Miller

Colorado potato beetle larvae are now emerging from eggs in the Rupert area. Growers who have not put on an at-planting insecticide need to apply a foliar insecticide.

Colorado Potato Beetle

Potato Treasure Valley - Idaho

Posted on: June 24, 2008 by Jerry Neufeld

A few Colorado Potato Beetle larvae are being found in the Greenleaf area. Growers should now be scouting for CPB larvae to time your foliar sprays.

Late blight forecast

Potato All Locations

Posted on: June 10, 2008 by Jeff Miller

The late blight forecast for the 2008 growing season in southern Idaho is negative. Even though we have been experiencing cool, wet weather recently, the amount of precipitation has still been relatively low compared to previous late blight years.

Additionally, temperatures have been outside the favorable range for pathogen development.

This forecast is only an estimate of the threat of late blight. It is still critical to scout fields for the presence of late blight as the canopy develops. Late blight is likely to be found first in the center span of pivots, in irrigation overlaps, field areas with sub moisture, along mainlines, or in shaded areas where periods of leaf wetness are extended.

If you find any suspicious lesions, please send them to University of Idaho personnel for confirmation.

Colorado Potato Beetle

Potato Treasure Valley - Idaho

Posted on: June 9, 2008 by Jerry Neufeld

Dr. Mike Thornton, from the UI Parma Research and Extension Center is reporting that overwintering Colorado Potato Beetle adults are beginning to emerge. This overwintering adult stage does not do any damage, however, they are looking for mates. In the next few days females will begin laying eggs in potato fields. We could see the damaging larvae appear in about 7 to 10 days depending on temperatures. Growers should be watching for the egg hatch to time a foliar spray for the first generation of CPB larvae.

Potato All Locations

Posted on: May 10, 2001 by Jerry Neufeld

The new 2001 Integrated Pest Management Program for Green
Peach Aphid/Potato Leaf Roll Virus for Pacific Northwest Potatoes
is now on the www.uidaho.edu/so-id/entomology homepage