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What A Difference A Year Makes

Nic Loyd; WSU AgWeatherNet Meteorologist;

Ag WeatherIf you have been wondering when warmer, late spring-like weather will finally arrive, you are probably not alone.  Temperatures in Washington have generally been near or below normal since December.  In fact, the 2016/2017 winter season (December to February) was central Washington’s coldest winter since 1984/1985.  However, it is important to note that the recent chill in early 2017 is only half of the story.  Although the cold 2016/2017 winter and the lack of prolonged springtime warmth so far this year may seem highly unusual, it is not, in a historical sense, as abnormal as one may suspect.  Much of the surprise of the early 2017 climate is related to the extreme warmth of the mid-2010s, as well as the suddenness of the pattern shift toward colder conditions that occurred in December 2016.  The interval from the spring of 2014 until November 2016 was one of unprecedented warmth for central/eastern Washington.  In fact, the temperature anomaly of central Washington’s two-year period from mid-2014 to mid-2016 (+3.9 deg) was almost double that of the now-second warmest (non-overlapping) biennium on record (+2.1 deg; 1990 to 1992).

The 2017 accumulated GDD (Growing Degree Days) total (base temperature 32 degrees F) for Pullman (through April 24) was 747 units, which is somewhat below the 2009-2016 average of 829 units.  However, the 2017 value is well below that of recent years (1081 and 1149 units in 2015 and 2016).  These numbers are illustrative of the fact that the perceived chill of 2017, though somewhat justified, is partly the result of the stark contrast with the remarkable warmth of the previous two years.

January 1 to April 24 Accumulated Growing Degree Days

Base Temperature 32˚F
Location 2017 Recent Avg Difference
Pullman 747 829 -82
Ritzville 710 893 -183
Fairfield 663 763 -100


(For further GDD information, please see the following link: ).

Given the volatility of our recent climate, one may reasonably wonder what weather regimes are anticipated for the near future.  Seasonal outlooks for later in 2017 suggest modest but appreciable odds that the state’s temperatures will again become generally warmer than normal.  Long range weather forecast models and decadal trends show an enhanced probability of above normal temperatures this summer, although abnormally cool waters in parts of the nearby Pacific Ocean act to slightly diminish those chances.  There is also a slight tilt toward abnormal dryness, although few clear signals exist regarding potential seasonal precipitation anomalies for the summer of 2017.

El Niño is a critical question mark going forward, and its ultimate strength/presence should significantly influence next winter’s climate pattern.  Unlike the weak La Niña conditions during the chilly 2016/2017 winter season, the notable potential for a weak to moderate El Niño augments the likelihood of a relatively warmer and drier winter of 2017/2018.  However, despite some indicators such as dynamical forecast models pointing strongly in that direction, other tools including historical analogs are more tempered about the eventual evolution of a robust El Niño event.  Therefore, its ultimate development later this year is favored but not yet certain.  Regardless of how Washington’s near-term climate patterns unfold, it seems likely that we can expect additional climatic surprises in the coming months and years.

For additional weather data and decision support information, please visit AgWeatherNet’s website,  To find weekly weather outlooks for Washington State, please select Outlook from the main page of the website, or visit the following link:

For questions or comments, contact Nic Loyd by email at


Stripe Rust Update – April 2017

Dr. Xianming Chen, USDA-ARS Research Plant Pathologist in Pullman, and Dr. Mike Flowers, Oregon State University Extension Cereal Specialist, released disease updates (Dr. Chen’s update and Dr. Flower’s update) during the past week.

Not surprisingly, stripe rust has continued to develop on winter wheat across the region and is relatively easy to find.  Dr. Flowers reported finding stripe rust at variety testing locations near Dufur and Moro, OR, and in a commercial field near Moro. Dr. Chen reported finding actively sporulating stripe rust during the week of April 5 in over 80% of the approximately 70 fields checked in Adams, Benton, Columbia, Franklin, Garfield, Walla Walla, and Whitman Counties in WA, and Umatilla County in OR.

OLYMPUS DIGITAL CAMERAStripe rust was most active near Walla Walla and Pendleton, where many fields have been sprayed with fungicide already. In other areas, rust ranged from 1 to 5% and is less severe than last year at this time due to lower temperatures. The Palouse in Whitman County is an exception, with stripe rust appearing about one month earlier than normal and similar to the severe epidemic years of 2011 and 2016.

Current weather forecasts continue to favor rust infection and spread, raising the potential for another severe stripe rust epidemic year. High-temperature adult plant resistance (HTAP) has not kicked-in yet and won’t become fully effective until nighttime/daytime temperatures are above 50°F/65°F.  Going forward, it will be important to continue scouting all winter wheat fields and consider using a fungicide with herbicide application if the variety is moderately susceptible or susceptible (rating 4 or greater in the Seed Buyers Guide) or active stripe rust is found on 2-5% of the plants in a field regardless of variety rating. Continue to monitor sprayed fields throughout the spring, especially near the end of fungicide effectiveness (3 to 4 weeks, depending on the fungicide).  For spring wheat, plant the most resistant variety available, preferably those rated 1 to 2.

Additional rust updates will be released as the growing season continues and conditions change. You can find additional information on stripe rust, including photos showing rust percentage, under Foliar Fungal Diseases in the Disease Resources section of the WSU Wheat and Small Grains website.

For questions or comments contact Tim Murray by email (, by phone (509) 335-7515, or Twitter (@WSUWheatDoc). For additional information contact Dr. Chen at or (509) 335-8086; or Mike Flowers at (541) 737-9940 or at

Proposed Rule Changes for Restricted Use Herbicides

RUPThe Washington State Department of Agriculture is considering rule changes affecting the use of restricted use herbicides. The possible rule changes were agreed upon by a workgroup consisting of various agricultural sector representatives and representatives from WSU.  The existing rules covering restricted use pesticides are extensive, complex, and confusing. For example, there are over 50 different established Areas in eastern Washington, each with their own restrictions. Some of the existing rules are over 50 years old and lack relevancy in today’s agriculture. For example, current rules require nozzles with a minimum orifice diameter, but current nozzle manufacturers and pesticide labels refer to the size droplet spectrum produced by a particular nozzle type at a specific pressure. The current rules also limit spray pressures below that needed by modern nozzle types such as air induction nozzles. The purpose of the proposed changes is primarily to repeal redundant and very outdated rules. The proposed new rules do not impose any additional regulatory requirements and the Department does not believe the changes will pose any increased risk to sensitive crops. The Department is seeking public comment on the proposed rule changes before filing an official rule-making proposal sometime in the fall of 2017.

The Department is considering the following changes:

  1. Amending nozzle and pressure requirements in the three WAC chapters to reflect current standards that applications must be made by creating a droplet spectrum size (e.g., medium, coarse or very coarse) that is in conformance with ASABE (American Society of Agricultural and Biological Engineers) standards;
  1. Repealing the 85 degree Fahrenheit cut-off requirement in individual county rules since it is in the statewide rule (redundant);
  1. Repealing maximum wind speed restrictions in individual county rules and adding a maximum 15 mph wind speed restriction to the statewide rules;
  1. Repealing restriction in statewide rules that limits the addition of oil carriers and adjuvants to one pint per acre;
  1. Repealing restrictions in individual county rules that prohibit use of oil type carriers for brush control during certain times of the year;
  1. Repealing restriction in statewide rules that prohibits mixing, loading and equipment decontamination (also aircraft takeoff and landing) in a manner that causes damage to susceptible crops;
  1. Repealing restrictions in counties and specific “Areas” of counties that limit mixing loading of aircraft to formulations that can be applied in the Area where the airstrip is located;
  1. Repealing the prohibition in statewide rules on turning or flying low over cities, towns, residences and other sensitive sites;
  1. Repealing the prohibition in the statewide rules for storing use-restricted herbicides in “Areas” where their use is prohibited unless they are in a sealed container and the outside of the container is not contaminated; and
  1. Repealing the provision in the statewide rules that indicates application of use-restricted herbicides through irrigation is subject to the same requirements as ground applications except for nozzle size and pressure requirements.

The Preproposal Statement of Inquiry provides details on how interested parties can provide comments on the proposed rule changes to the Washington State Department of Agriculture. The Explanation of Possible Rule Changes explains the proposed rule changes and why the changes are deemed beneficial.  This is a good faith effort to simplify and update rules related to the application of restricted use herbicides. Please consider providing your thoughts on the proposed rule changes to the Washington State Department of Agriculture.

For questions, contact Drew Lyon by phone at 509-335-2961 or by email at


Raising the Quality Bar

2017 Preferred VarietiesEach spring the Idaho, Oregon and Washington grain commissions publish the Preferred Wheat Varieties brochure.  The document ranks current commercial wheat varieties based on their end-use quality and the 2017 edition has just been published!

The Preferred Wheat Varieties brochure serves the grain industry by providing customers of Pacific Northwest (PNW) wheat with a ranking of varieties they may see in their next purchase.  Varieties are ranked from highest to lowest quality, based on their performance against a known check variety.  Some of the quality parameters that go into the overall ranking are milling and baking performance, grain protein, and test weight.  In order for a variety to end up on the list, it must be evaluated in the quality labs for at least three years.

Because the overwhelming majority of our PNW wheat is exported to customers who demand a high-quality product, farmers can help maintain PNW market share by planting high-quality varieties.  When choosing between two comparable varieties to plant on their farm, growers are encouraged to choose the variety that is higher up on the quality list.

For questions, contact Ryan Higginbotham by email at or by phone at 509-335-1205.

Podcast Dissects Falling Number Phenomenon

Paperboy_1400Learn more about the discount that cost Eastern Washington wheat farmers at least $30 million and perhaps as much as $140 million in 2016.

Episodes 12 & 13 of the Washington Grain Commission-sponsored podcast, Wheat All About It! both address falling numbers. The two podcasts are from a falling numbers panel held during Spokane Ag Expo.

The first, Falling Numbers 101, features Central Washington Grain Growers grain merchandiser Ty Jessup, also a WGC commissioner, and Don Potts, regional manager of the Washington State Grain Inspection Service. They explain the phenomenon from their professional perspectives. Episode 13, Falling Numbers 102, is devoted to Arron Carter, Washington State University winter wheat breeder, who addresses the science behind the discount.

And while you’re there, listen to Episode 9, Going to the Wheat Academy. Go to or subscribe to the podcast on iTunes and Facebook by searching for Wheat All About It!

View the Wheat All About It! podcasts here.

For questions, contact Scott Yates with the Washington Grain Commission at .

Benefit to Washington Wheat Producers Associated with Increased Farmer Program Flexibility

Wheat farmers signing up for U.S. farm program benefits in early 2015 were asked to select between a revenue based program (Agricultural Risk Coverage – ARC) or a price based program (Price Loss Coverage – PLC). Once a choice was made, the choice was binding over the entire life of the 2014 Farm Bill. This created a challenge because the two programs generate very different benefit streams under different market scenarios. The ARC program generally provides superior benefits if prices stay above the PLC target price ($5.50 per bushel for wheat), or if producers expected significant yield variation over the life of the farm bill. If market prices fall below the PLC target, and yields are stable or increasing, the PLC program will generally provide greater protection. The analysis presented here looks at the cost to Washington wheat producers associated not being able to switch between ATC and PLC as market condition change.

For questions contact Randy Fortenbery at 509-335-7637 or

Pink Snow Mold Destruction Discovered in Area Wheat Fields

Furrows of bleached-looking leaves of winter wheat damaged by pink snow mold in a Prescott, Wash., field.

By Linda Weiford, WSU News

Damage caused by snow mold in some eastern Washington wheat fields has surprised a Washington State University plant expert who has studied the fungus for nearly four decades.

Melting snow is exposing patches of injured wheat in parts of the state where destruction by snow mold is rarely seen, said WSU plant pathologist Tim Murray. He recently met with 20 growers in the town of Prescott, Wash., to address their concerns about the mold’s impact on winter wheat.

“Growers in this area have never seen this mold until now,” he said. “Its presence may have surprised me, but it really surprised them.”

After examining a half-dozen fields in southcentral and southeastern Washington, Murray identified winter wheat damage ranging from nonthreatening lesions on leaves to underground crown decay that kills the crop.

“I was surprised to see how prevalent the damage was in some of the fields,” he said. “We’ll definitely be seeing some economic damage as a result.” He stressed that the extent can’t be tallied until soils are warm enough to reveal which plants could withstand the damage and which could not.

Pink Fungus Among Us

A cold-loving organism that thrives under long periods of snow cover, so-called pink snow mold attacks perennial plants and overwintering crops. It’s more commonly seen in the higher elevations of northcentral Washington where snow blankets the ground for 100 days or more.

The pink color’s intensity fades with exposure of the mold to sunlight.

But this winter’s pervasive snowy weather fueled the mold’s growth in lower elevations as well, said Murray, including Walla Walla, Whitman and Columbia counties. Caused by the fungus Microdochium nivale, the pink-tinged mold is showing up in fields of winter wheat and even lawns of grass, he said.

“Snow protects winter wheat and other dormant plants from cold temperatures, which is a good thing,” he explained. “But the snow cover becomes a problem when it stays on the ground for too long, which is just what happened.”

In areas where the fungal disease is evident, snow had covered the ground 60-70 days. Although longer than most years, “it’s still not long enough to cause the kind of damage I’ve been seeing. It typically takes at least 100 days,” said Murray.

Why, then, is the fungus among us? Abnormally warm temperatures in November kept the ground from freezing before the first hard snow arrived, creating a more hospitable environment for Microdochium nivale to grow, he explained. That, coupled with a longer-than-usual period of snow cover, gave it just what it needed to thrive.

“The fungus is out there. As we’ve seen, when the weather allows it to take advantage of the situation, it does,” he said.

Growers Advised to Wait

Murray has spent 40 years helping to develop high-quality wheat varieties that mount a defense reaction against snow mold and other diseases that plague the crop in cold climates. Microdochium nivale is one of three fungi that cause snow mold in Washington.

Murray is advising growers to let a few weeks of warmer weather pass in order to assess the full impact of damage in their fields. At that point, they can decide whether reseeding will be necessary.

For questions or comments, contact Tim Murray by phone at 509-335-7515, by email at, or on Twitter @WSUWheatDoc or contact Linda Weiford at 509-335-7209 or To view this story on WSU news, click here.

White Paper: Strategies to Reduce Economic Losses Due to Low Falling Number in Wheat

The White Paper was developed after the recent Falling Numbers Summit in Spokane, WA on Feb 16, 2017. That event was unique because it brought together a wide group of members of the grain industry, including federal and state grain inspectors, elevator operators, grain millers and bakers, the research community, grain commissions and grower groups, exporters and state extension services and representatives from private sector agronomy and plant breeding companies.

Since 2011, low falling numbers have cost western farmers millions of dollars. Economic losses to the grain industry in 2016 alone exceeded $30 million at harvest and will likely approach $140 million in total. The two causes of low FNs in wheat grain are: 1) pre-harvest sprouting or germination on the mother plant due to rain before harvest, and 2) late maturity alpha-amylase (LMA) due to heat or cold shock during grain development.

At the meeting, the members of the grain community shared current knowledge, determined where more knowledge is needed, developed priorities for action and assigned leaders to each priority action item. The focus of the meeting was on short (3-6 month) and mid-term (6 months to 2 years) strategies. The white paper identifies the strategies and outcomes from that meeting. The immediate goals are to improve the Falling number test by increasing the standardization of the testing protocol and to analyze existing data to detect patterns in the response of wheat varieties.  All results will be posted on the Small Grains Grain Quality Resources page.

A follow-up meeting for researchers will occur at the Western Wheat Workers Conference in Corvallis, May 31-June 1 and a follow-up meeting for the industry will occur at the Tri-State Grain Growers Convention in Spokane in November 2017.

For questions or comments, contact Kimberly Campbell at (208) 310-9876 or at

Stripe Rust Update – March 2017

Wheat leaf infected with stripe rust, also known as yellow rust (Puccinia striiformis). The pustules caused by stripe rust contain yellow to orange-yellow urediospores and usually form stripes on the leaves. For more information, see CIMMYT's Wheat Doctor: Photo credit: Thomas Lumpkin/CIMMYT.

Photo credit: Thomas Lumpkin/CIMMYT

Dr. Chen, USDA-ARS Research Plant Pathologist in Pullman, and the Oregon State University Variety Testing and Plant Pathology Team (Mike Flowers, Larry Lutcher, Christina Hagerty and Chris Mundt) each released disease updates (Dr. Chen’s report and the Plant Pathology’s report) during the past week.

Using six different models based on air temperature, Dr. Chen is predicting this year’s stripe rust epidemic will be more severe than his first prediction in January.  Although air temperature during several periods in December and January was below the 5°F threshold for survival of the stripe rust fungus in plants, most of the wheat-growing area in eastern Washington had a blanket of snow cover that protected both winter wheat plants and the fungus, allowing both to survive. Consequently, Dr. Chen is now predicting an epidemic with potential yield loss of 32% on highly susceptible varieties, compared to 6% in his January forecast. Dr. Chen also reported finding actively sporulating stripe rust pustules during the week of March 6 in Walla Walla County where the wheat has greened-up and started growing. Fields farther to the north in Adams and Lincoln Counties were either still under snow or, where snow was gone, had dead spots where rust infection was severe last fall, or fall-infected leaves were dead. It is possible that the stripe rust fungus is still alive in these plants and may begin to sporulate once the plants begin growing again. These observations were confirmed in the OSU report, and stripe rust was observed on several varieties at two variety testing locations (Lexington, OR and Walla Walla, WA) and appears to be widespread in eastern Oregon and southeastern Washington.

Going forward, it will be important to scout all winter wheat fields and consider using a fungicide with herbicide application if the variety is moderately susceptible or susceptible (rating of 5 to 9) or active stripe rust is found on 2-5% of the plants in a field. Continue to monitor fields throughout the spring, especially as the end of fungicide effectiveness nears (3 to 5 weeks, depending on the fungicide).  For spring wheat, plant the most resistant variety available, preferably those rated 1 to 4.

For questions or comments, contact Dr. Chen at or (509) 335-8086 or Tim Murray by email (, by phone (509-335-7515), or Twitter (@WSUWheatDoc).

Metalaxyl-resistant Pythium

Pink MediaMetalaxyl is the active ingredient in fungicides such as Ridomil, Apron, Subdue, and others used to prevent root rots and seedling diseases caused by the fungus-like organism Pythium. Called Oomycetes, these fungus-like organisms require water for a portion of their life cycle, because most produce a swimming spore and are more closely related to brown algae than to true fungi like stripe rust. Other common oomycetes are the downy mildew and the late blight pathogen on potato. Pythium is a soilborne pathogen present in most agricultural soils that is able to attack a diversity of crops grown in the PNW including wheat, chickpeas (Chen and Van Vleet, 2016), lentils, canola, potatoes (Porter, et. al, 2009), other vegetables, and even the tree fruit. Because Pythium is not a true fungus, only certain fungicides can be used to protect a crop with, metalaxyl being most frequently used, most often in the form of a seed treatment. Unfortunately, in both potato-producing regions and in chickpea production in the Palouse, metalaxyl-resistant Pythium have been found. These resistant Pythium species are able to cause damping-off, stand and crop loss, and leak (in potatoes) despite the seed treatments. The fungicide ethaboxam is proposed as an alternative for managing metalaxyl resistant Pythium populations. As metalaxyl is our main weapon against Pythium and other oomycetes, it is vital that we be aware of developing resistance so that we can manage these populations and slow further development. Changes in management practices that encourage the rapid growth of seedlings and reduces cool, wet soil conditions until plants are robust enough to withstand minor damage can also help reduce the impact of Pythium.

If you suspect that you may have metalaxyl resistant Pythium, you are encouraged to submit a soil or plant sample to the Plant Pest Diagnostic Clinic in Pullman for testing

For more information:

Weidong Chen and Steve Van Vleet. Chickpea damping-of due to metalaxyl-resistant Pythium: an emerging disease in the Palouse. 2016.


Cook, R.J. and B.X. Zhang. 1985. Degrees of sensitivity to metalaxyl within the Pythium spp. pathogenic to wheat in the Pacific Northwest. Plant Disease 69: 686-688.

Porter, L.D., P.B. Hamm, N.L. David, S.L. Gieck, J.S. Miller, B. Gundersen, and D.A. Inglis. 2009. Metalaxyl-M-resistant Pythium species in potato production area of the Pacific Northwest of the U.S.A. American Journal of Potato Research 86: 315-326.

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