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Small Grains Facing Big Issues
All Crops Eastern Idaho, Magic Valley
BYD< eyepsot, dorught and freezes
Posted on: May 11, 2026 by Juliet Marshall
My initial concerns
were that conditions favored aphids and spread of BYDV (barley yellow dwarf
virus), a plant virus transmitted by aphids. The other concern was that
conditions were optimal for plant infections of the fungi causing eyespot, favored
by short crop rotations, early seeding, high fall biomass, high seeding rates
and cool wet fall weather followed by a mild winter.
Growing Degree Days
(GDD) were high throughout winter resulting in crop growth advancing about a
month earlier than usual. Warm conditions resulted in continued water usage by
the crop leading to drought stress. The earliest irrigations could not start
until water was in the canals or ground water pumping was permitted. Consistent
high winds increased evapotranspiration and physical stress.
Mites also thrived
with high populations causing extensive plant damage in several areas.
While March was warm,
April became cold. Temperatures dove to the teens and twenties several nights,
and for several weeks in a row temperatures were consistently below freezing. Successive
freezes are damaging to winter grain in these advanced stages and also resulted
in delayed herbicide applications.
Taken individually,
let’s review possible management strategies.
1)
Aphid transmission of BYDV.
a.
Delayed fall planting to avoid high aphid
populations migrating in from other crops. Populations can build on corn, then
migrate to newly planted winter cereals. Barley yellow dwarf viruses, triticum
mosaic viruses and high plains viruses migrate with aphids, reducing plant growth
and yields. Cons: delayed planting reduces plant size going into the
winter and may reduce winter survival and subsequent yields. Larger plants have
larger more established crowns that survive cold temperatures and snow mold
infection (should there be a good snow year…)
b.
Insecticidal seed treatments reduce aphid
populations and limit the spread of viruses. Cons: Seed applied
insecticides are recommended for early plantings but are effective for limited
time after plant emergence. Seed treatment costs increase with added
insecticides and viruses may still be transmitted before insects are killed. As
plants continue to grow, the effectiveness of the insecticide is reduced over
time. There also is limited effectiveness in long, warm falls when no killing
frosts reduce aphid populations.
c.
Insecticide applications after crop
emergence directly kill aphids and prevent further colonization, also reducing
virus transmission. Cons: increased production / application costs, and potential
impacts on beneficial insects.
2)
Eyespot management.
a.
Increase crop rotation to promote soil
and plant health, reducing insect, nematode and fungal pathogen build up while
promoting sustainable ag ecosystems. Cons: are there any? Well yes,
environmental, economic and market forces may restrict rotational crop options.
b.
Reduce seeding rates to reduce the
environmental conditions that allow the fungal pathogens to proliferate (lush
fall growth). Winter cereals are effective at tillering to meet environmental
constraints. If there is plenty of space, plants will tiller more. Crowded
plants compete more with each other, resulting in weaker stems and taller plants
that lodge more. Crowded conditions also reduce airflow, increase moisture in
the lower canopy and promote stem-based infections of fungal pathogens. Cons:
fewer plants per acre may result in thin plant stands when conditions favor
winter kill.
c.
Delay fall planting, especially as
the growing seasons lengthen; to increase the chance that heavy frosts or
freezes kill aphids. Cons: planting of fall grains may conflict with
late harvests of potatoes and sugar beets. When there are limited planters and
large acreage to cover, getting everything planted in a timely fashion is
difficult.
d.
Apply triazole-based fungicides at herbicide
timing, before stem elongation to reduce impacts from fungal infection. Cons:
Timing of herbicide applications may be too late for optimum control of fungal
infections. Timely application of fungicides may require an additional field
operation that can add to input costs.
3)
Excessive fall growth due to favorable
weather conditions.
a.
Reduce seeding rates to prevent high plant
populations. Winter cereals compensate and tiller well to fit the environment. Cons:
It is hard to predict the fall and winter environment and the impact on grain
growth.
b.
Excessive growth can be managed with grazing to
reduce plant biomass and conditions that favor soil-borne fungi. Cons:
Accessibility of cattle to graze and fencing.
4)
Drought stress increases with warm
winters while plants continue to grow.
a.
Delay planting date to reduce excessive fall
growth and soil water usage. Cons: Long-term weather forecasts are
difficult, and conditions are more favorable for certain soilborne diseases.
b.
Minimize working the soil to reduce water loss. Cons:
poor seedbed preparation reduces uniform plant stand, especially following
harvest of root crops. No- or minimum-till practices are not possible with
potato and sugar beet crops.
5)
Freezing and Frost damage in spring.
a.
Delay fall planting. Early planting leads to
abundant plant growth. Cons: Warm winter conditions cannot be accurately
predicted.
b.
Irrigate well prior to winter to replenish soil
moisture. Drought conditions increase winter kill and advance plant growth
stages, leading to early heading. Cons: availability of irrigation for
winter cereals prior to winter.
6)
Mite damage in fall and spring
a.
Delay fall planting to reduce green bridge. Cons:
It is difficult to delay fall planting in dryland production which depends
foremost on soil moisture conditions.
b.
Insecticidal treatment to reduce mite
populations in the spring. Cons: Cost of application.
All of these issues
seem to be occurring simultaneously this year. Many winter cereal fields are
experiencing aphid-transmitted viral infections (BYDV-PAV, BYDV-MAV, CYDV,
triticum mosaic virus). Many winter barley fields are advanced in plant growth
stage, heading out early due to warm, dry conditions. Plants are stressed due
to drought. On top of very short plants, weeks of freezes in April have caused
extensive damage. Options include abandoning the crop, grazing or green-chop
remaining foliage or salvaging whatever remains, which won’t be much. Winter
barley has been the most affected by these conditions. After the freezes, about
50% of the heads are frozen and dead. Many stems of winter wheat and barley are
frozen at the base, collapsing stems, freezing heads in the boot, and resulting
in blackened lesions about an inch above the soil line.
Another option would
be to mow affected fields, allowing plants to tiller again from the base of the
plant. Roots are established and plants will develop new tillers. We do not
have data on yield potential under these circumstances, but it would produce
grazable forage or a minimum grain yield.
Contact your insurance
agent to have a loss adjuster estimate damage. You may be required to maintain
a representative strip. (Unfortunately, irrigating anything under current water
restrictions seems of limited value.) Be prompt in filing a notice of loss, as
it may take some time for an adjuster to survey the damage. Do not abandon or
destroy the crop until the crop (or field) is released by the adjuster.
(Disclaimer: I am not an insurance expert.)
This current situation
places us in an unenviable position of having greater spring yields than winter
grain yields. All of the suggestions discussed have economic factors that must
be weighed. And of course, some fields are more affected than others, even
within the same area. Please don’t hesitate to reach out for support, including
to the University of Idaho Farm Stress Team - Bracken Henderson (brackenh@uidaho.edu),
Lance Hanson (lancehansen@uidaho.edu), and David Callister (dcallister@uidaho.edu).
First codling moth flight of 2026 detected in Latah County
General Landscape and Garden Northern Idaho
Codling Moth
Posted on: May 8, 2026 by Samuel DeGrey
Multiple codling moths were captured in a monitoring trap in Moscow, Latah County, Idaho on May 6th, 2026.
The first detected flight date of May 6th will serve as the biofix, or the date where we begin accumulating degree days, for Moscow, Idaho. Degree days provide an estimate for life cycle stages of insect pests, and can be a tool to better time management decisions for farmers, horticultural professionals, and gardeners.
Please visit our degree day dashboard to track degree days for codling moth in Moscow - https://pnwpestalert.net/gdd/index
Please consult the Pacific Northwest Pest Management handbook for degree-day based management recommendations for codling moth - https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth .
First apple codling moth flight of 2026 detected in Ada County
All Crops Eastern Idaho, Magic Valley, Treasure Valley, Treasure Valley - Idaho, Northern Idaho, Treasure Valley Oregon
Codling Moth
Posted on: May 8, 2026 by Sierra Laverty
First apple codling moth flight of 2026 detected in Ada County
Multiple codling moths were captured in a monitoring trap at Spaulding Ranch in Boise, Ada County, Idaho on May 1st, 2026.
May 1st will serve as the biofix for codling moth at the trapping site. Biofix is a specific, biological event used as a starting date for estimating the timeline of an insect’s lifecycle. An insect’s lifecycle is estimated using degree days (DD), which are units that measure how cold or warm an area is over time, based on if the average temperature is one degree above or below a specific base temperature. Adult codling moths were detected at 170 DD in Ada County. Please note that microclimates in the Treasure Valley are highly variable and your particular site may be colder or warmer than the monitoring site at Spaulding Ranch.
Management actions:
Thin fruit clusters to one fruit to reduce contact points between fruits now
Apply coverage insecticide sprays at 250 accumulated DD since May 1st or 420 total DD since January 1st. Another alert will be posted through PNW Pest Alert Network at that time.
To track degree days in the Treasure Valley, visit our website: https://pnwpestalert.net/gdd/index
Please consult the Pacific Northwest Pest Management Handbook for degree-day based management recommendations for codling moth: https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth
What is codling moth? Codling moth is a key insect pest of apples and pears in Idaho. Left unmanaged, it can cause "wormy" fruit and significant crop loss.
Identification – Know the Signs & Symptoms
Symptoms on Fruit:
Small, dark entry holes ("sting") on the apple surface.
Frass (sawdust-like excrement) near the hole.
Tunnels inside the fruit leading to the core.
Premature fruit drop in severe infestations.
Current Monitoring & Degree Days:
Biofix (first moths detected): May 1
Current Degree Days (base 50°F): 262 DD as of May 8
Egg hatch begins: 220-250 DD
Management Options
Non-Chemical Options
Fruit thinning: Thin clusters to one fruit to reduce contact points between fruits.
Fruit Bagging: Bag individual fruits to block larvae entry.
Sanitation: Remove dropped fruit and prune trees to reduce overwintering sites.
Coverage Insecticide Sprays
When: Apply at 250 DD after biofix (420 DD total since January 1st, based on 2026 monitoring)
Action: Apply insecticides to kill newly hatched larvae before they burrow into fruit.
For insecticide options: https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth
All pesticides, including least-toxic alternatives, have benefits and potential hazards. You must read and follow the pesticide label for specific directions, paying close attention to the directions for use and application rates. Inconsistent use of a product or disregarding the label is a violation of both state and federal laws.
For season-long control: Codling moth has multiple generations per season. Continue monitoring traps and tracking degree days to time follow-up sprays and other control measures.
For more assistance, contact your local University of Idaho Extension office: https://www.uidaho.edu/extension/directory/counties
» https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth
» https://climate.usu.edu/includes/pestFactSheets/Codling-Moth.pdf
» https://extension.colostate.edu/topic-areas/insects/codling-moth-control-in-home-plantings-5-613/
Codling Moth Detected in Traps in Boise
General Landscape and Garden Treasure Valley, Treasure Valley - Idaho
Codling Moth
Posted on: May 8, 2026 by Sierra Laverty
First apple codling moth flight of 2026 detected in Ada County
Multiple codling moths were captured in a monitoring trap at Spaulding Ranch in Boise, Ada County, Idaho on May 1st, 2026.
May 1st will serve as the biofix for codling moth at the trapping site. Biofix is a specific, biological event used as a starting date for estimating the timeline of an insect’s lifecycle. An insect’s lifecycle is estimated using degree days (DD), which are units that measure how cold or warm an area is over time, based on if the average temperature is one degree above or below a specific base temperature. Adult codling moths were detected at 170 DD in Ada County. Please note that microclimates in the Treasure Valley are highly variable and your particular site may be colder or warmer than the monitoring site at Spaulding Ranch.
Management actions:
Thin fruit clusters to one fruit to reduce contact points between fruits now
Apply coverage insecticide sprays at 250 accumulated DD since May 1st or 420 total DD since January 1st. Another alert will be posted through PNW Pest Alert Network at that time.
To track degree days in the Treasure Valley, visit our website: https://pnwpestalert.net/gdd/index
Please consult the Pacific Northwest Pest Management Handbook for degree-day based management recommendations for codling moth: https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth
What is codling moth? Codling moth is a key insect pest of apples and pears in Idaho. Left unmanaged, it can cause "wormy" fruit and significant crop loss.
Identification – Know the Signs & Symptoms
Symptoms on Fruit:
Small, dark entry holes ("sting") on the apple surface.
Frass (sawdust-like excrement) near the hole.
Tunnels inside the fruit leading to the core.
Premature fruit drop in severe infestations.
Current Monitoring & Degree Days:
Biofix (first moths detected): May 1
Current Degree Days (base 50°F): 262 DD as of May 8
Egg hatch begins: 220-250 DD
Management Options
Non-Chemical Options
Fruit thinning: Thin clusters to one fruit to reduce contact points between fruits.
Fruit Bagging: Bag individual fruits to block larvae entry.
Sanitation: Remove dropped fruit and prune trees to reduce overwintering sites.
Coverage Insecticide Sprays
When: Apply at 250 DD after biofix (420 DD total since January 1st, based on 2026 monitoring)
Action: Apply insecticides to kill newly hatched larvae before they burrow into fruit.
For insecticide options: https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth
All pesticides, including least-toxic alternatives, have benefits and potential hazards. You must read and follow the pesticide label for specific directions, paying close attention to the directions for use and application rates. Inconsistent use of a product or disregarding the label is a violation of both state and federal laws.
For season-long control: Codling moth has multiple generations per season. Continue monitoring traps and tracking degree days to time follow-up sprays and other control measures.
For more assistance, contact your local University of Idaho Extension office: https://www.uidaho.edu/extension/directory/counties
» https://pnwhandbooks.org/insect/tree-fruit/apple/apple-codling-moth
» https://climate.usu.edu/includes/pestFactSheets/Codling-Moth.pdf
» https://extension.colostate.edu/topic-areas/insects/codling-moth-control-in-home-plantings-5-613/
2026 Snake River Weed Management Field Tour
All Crops All Locations
Posted on: May 6, 2026 by Russel Smith-Ollivierre
Mark your calendar for Thursday, June 11, 2026, and join us
at the Malheur Experiment Station for the first stop of the Snake River Weed
Research Tour.
This annual Field Day highlights ongoing weed management
research across the Treasure Valley of eastern Oregon and southwestern Idaho,
with a focus on key crops such as onion and sugar beet. This year’s program
also includes biofumigation cover crop trials. Walk the fields, see results
firsthand, and connect with OSU scientists and staff.
Attendees may receive up to three pesticide credits for
Oregon and Idaho.
Event Schedule
Location: Malheur Experiment Station, 595 Onion Ave,
Ontario, OR
Registration: 8:00–9:00 AM
Tour: 9:00 AM–12:00 PM
Lunch: Provided at noon
The event is free and open to all, but please RSVP to ensure
adequate lunch.
RSVP & Information
Jan Jones
541-889-2174
janet.jones@oregonstate.edu
Western Conifer Seed Bug capable of damaging PEX plumbing lines
General Landscape and Garden Northern Idaho
Western Conifer Seed Bug
Posted on: May 1, 2026 by Samuel DeGrey
Western Conifer Seed Bugs (Leptoglossus occidentalis,
often incorrectly referred to as "stink bugs" or "pine
beetles") are one of the west's most commonly encountered insect species.
While generally considered a mere nuisance due to the species' habit of
overwintering in human structures, western conifer seed bugs are actually
capable of damaging cross-linked polyethylene tubing (PEX) used in indoor
plumbing in many homes. When overwintering seed bugs are trapped indoors for
long periods of time during the colder months, they may attempt to
"taste" random objects with their piercing-sucking mouthparts, which
can cause leaks in the soft plastic when they pierce through the PEX line. See linked publication for further information, including on how to distinguish
western conifer seed bug damage from other forms of damage to plumbing lines.
Plastic outdoor irrigation line is unlikely to be at risk from seed bug
damage.
Homeowners have confirmed Western Conifer Seed Bug damage to
PEX plumbing line in Bonner County, Idaho in 2026. Years with increased seed
bug populations may represent higher risk of damage to pipelines. The end of
the colder months may represent a good time to inspect any indoor PEX line for
seed bug damage.
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/5D1C0B6A542A427186A697E39B9C92D0/S0008347X00002807a.pdf/damage-to-common-plumbing-materials-caused-by-overwintering-leptoglossus-occidentalis-hemiptera-coreidae.pdf
Ag Talk Tuesday resumes for the 2026 season
All Crops All Locations
Posted on: May 1, 2026 by Kasia Duellman
Save the Date: Ag Talk Tuesday – 2026 Season
Please mark your calendars for the 2026 season of Ag Talk Tuesday, hosted by the University of Idaho Extension. Sessions will be held from 11:00 AM to Noon (MDT) on the first and third Tuesdays of each month, May through August.
We’ll kick off the season on May 5 with a water update.
Each Ag Talk Tuesday session begins with approximately 30 minutes of informal crop reports led by UI Extension personnel. All attendees are encouraged to participate and share observations or updates. The second half of the session features a more structured presentation on a timely agricultural topic, delivered by a guest speaker. An Ag Talk Tuesday organizer facilitates each session to guide discussion, gather crop updates, and moderate questions for the featured presentation.
Registration is free but required.
To register, please visit the Ag Talk Tuesday website:
https://www.uidaho.edu/extension/events/ag-talk
Or register directly using this link:
https://uidaho.zoom.us/meeting/register/xJRvquC7T66Czb_qpW0A_A#/registration
We hope you can join us for a productive and informative season of Ag Talk Tuesday!
Sincerely,
Your Ag Talk Tuesday Organizers
Emily Bedwell (ebedwell@uidaho.edu)
Kasia Duellman (kduellman@uidaho.edu)
Doug Finkelnburg (dougf@uidaho.edu)
Juliet Marshall (jmarshall@uidaho.edu)
