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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 kim.garland-campbell@ars.usda.gov.

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: http://wheatdoctor.cimmyt.org/index.php?option=com_content&task=view&id=113&Itemid=43&lang=en. 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 xianming@wsu.edu or (509) 335-8086 or Tim Murray by email (tim.murray@wsu.edu), 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 http://plantpath.wsu.edu/diagnostics/clinic-services/.

For more information:

Weidong Chen and Steve Van Vleet. Chickpea damping-of due to metalaxyl-resistant Pythium: an emerging disease in the Palouse. 2016. http://hdl.handle.net/2376/6273

Reference:

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.

Variable Rate Nitrogen Application – A Grower’s Perspective

winter wheat fieldThe unique, hilly topography of the inland Pacific Northwest causes great within-field variability in soil and water conditions. As a result, crop yield potential and crop response to nitrogen (N) applications will vary according to the hillslope position, steepness, and aspect of any planted location. Thus, variable rate N (VRN) application makes sense for growers in this region.

In a recently published case study, Variable Rate Nitrogen Application: Eric Odberg, a grower from Genesee, Idaho, shares his 10 years of experience using VRN application in a direct seeding (no-till) system. Although transitioning to VRN application is a big decision with many challenges along the way, Eric’s 10 years of experience has brought him numerous benefits. These benefits include reduced fertilizer input, reduced lodging, reduced risk of N losses to the environment, and increased financial gain. Furthermore, because Eric complements VRN application with direct seeding and diversified crop rotations, his farm’s soil quality has also improved.

For questions or comments, contact Georgine Yorgey (yorgey@wsu.edu) or Sylvia Kantor (kantors@wsu.edu) at the Center for Sustaining Agriculture and Nature Resources, Washington State University, or Kathleen Painter (kpainter@uidaho.edu) at the Department of Agricultural Economics and Rural Sociology, University of Idaho.

Concern Over Snow Mold of Wheat in Eastern Washington

The winter of 2016-17 has been unusually long compared to the past few years, and the prolonged snow cover has raised concerns over potential for snow mold development in eastern Washington. On the Waterville Plateau in Douglas County where snow mold of wheat has been a chronic occurrence since the 1940s, snow has been on the ground for nearly 100 days since sometime in early November. In Pullman, near the opposite corner of wheat producing area, snow has covered the ground continuously since December 6, or about 60 days. Snow cover is like putting a blanket on your bed – it keeps the warmth in and the cold out.  For the wheat crop, a blanket of snow cover provides a layer of insulation that helps wheat plants survive the winter by protecting them from bitterly cold temperatures and wind that can result in winterkill. However, if the snow stays too long, the potential for damaging snow mold can occur.

Gray snow mold 2 jpegSnow mold is a generic name for any one of several diseases that can develop on wheat under snow. The pathogens that cause these diseases are specialized and able to grow in the wet, near-freezing environment under the snow and destroy most of the aboveground foliage. In eastern Washington, snow mold can be caused by one of four different fungal or fungal-like pathogens; however, speckled snow mold and pink snow mold are the most common and destructive. Speckled snow mold is the most destructive disease in eastern Washington and needs about 100 days of continuous snow cover with unfrozen soil before damage is likely to occur. This disease is most common in the wheat-growing area north of highway 2 beginning about Almira west to Waterville.  Pink snow mold can occur alongside speckled snow mold, but is favored by slightly wetter conditions and usually doesn’t cause damage to wheat over large areas. Pink snow mold is more widespread than speckled snow mold because it doesn’t require as much snow cover to develop, so it’s also common in golf course turf and home lawns. There is another snow mold fungus that resembles the speckled snow mold fungus that occurs widely in eastern Washington; it is often called gray snow mold or Typhula root and crown rot because it often develops below ground and is distinguished by the reddish-colored speckles that develop on infected plants. This disease causes little damage to wheat, but can be very destructive to winter barley.

Most growers in the traditional snow mold area know that planting a resistant variety early is the best way to control snow mold. Outside of the Waterville Plateau, pink and gray snow mold likely will be apparent in some spots when the snow melts. However, they are unlikely to cause significant damage where snow cover was less than about 8” deep because the near-zero temperatures we experienced in late December and early January will have frozen the soil, which limits disease development. It is also likely that there will be some leaves killed by the cold temperatures. To determine whether snow mold was the cause, look closely at the dead plant parts for evidence of a cob-web-like growth on the surface. With pink snow mold, plants will have a salmon-pink color soon after snow melt; the color will fade leaving brown-colored tissue. For the speckled snow molds, evidence of disease is the presence of dark-colored survival structures known as sclerotia. Plant parts killed by cold may appear light brown or bleached without any of the signs of snow mold.  Samples can also be submitted to Plant Pest Diagnostic Clinic for confirmation.

For more information, consult extension bulletin Snow Mold Disease of Winter Wheat in Washington (EB1880) available under publications in the Disease Resources section of the WSU Wheat and Small Grains website.

Contact Tim Murray for questions/comments at tim.murray@wsu.edu, 509-335-7515 or on Twitter @WSUwheatdoc.

Standing Crop Residue Can Reduce Snow Drifting and Increase Soil Moisture

Snow Drift Haiying

Soil water recharge and storage is important in the inland Pacific Northwest because approximately 70% of the region’s precipitation occurs between October and March. Of this 70%, approximately 35% is in the form of snow. Trapping more snow can increase soil water storage for the growing season and also provide insulation to protect plants from winterkill.

In the unique, hilly topography of the Palouse, ridge tops and south-facing slopes generally retain the least amount of snowpack and valley areas retain the most. This variable snow distribution is mainly caused by wind induced snow drifting and snowmelt runoff. These differences in depth and duration of snowpack can cause substantial spatial variation in soil-water availability. In addition, the excessive water in areas with heavier snow accumulations can cause nitrogen loss from leaching, runoff, and denitrification.

The redistribution of snow by wind and water can be substantially reduced by leaving crop residue standing and practicing no-till. At all topographic locations, no-till retains more soil water with less spatial variation in snow depth than conventional tillage. Compared with chopped residue left on the soil surface, standing crop residue such as wheat and sunflower stubble is more effective not only for reducing wind speed and evaporation, but also for increasing snow catch. In no-till, snow catch generally increases as stubble height increases.

One research project, conducted in the Palouse near Pullman, Washington, compared a no-till field with a conventionally tilled field during multiple snow events and after snowmelt in spring. Compared with the conventionally tilled field, no-till ridge tops with standing wheat residue at 3.5 to 13 inches tall retained 3.9 to 4.7 inches more snow. Similarly, no-till south-facing slopes with standing wheat residue at the same height retained 3.9 to 5.5 inches more snow. By spring, the no-till field stored 2.4, 1.1, and 0.5 inches more water in the 5-foot soil profile at ridge tops, south-facing slopes, and valley locations, respectively, compared to the conventionally tilled field. Another project, a long-term study in Saskatchewan, Canada, concluded that leaving 35 to 47 inch-wide strips of standing stubble residue, about 16 to 24 inches tall every 20 feet, trapped 1.6 times more snow than shorter stubble at 12 inches tall.

Tall standing stubble, achieved by harvesting with a stripper header and leaving stubble at full-crop height, can conserve water and reduce residue decomposition rates. Tall standing stubble is especially important for sparse stands. A 4-year study conducted in a low-rainfall area near Ralston, Washington, found that this practice can reduce soil surface temperatures and also slow soil surface wind speeds to less than one half of the average. The stripper header-managed winter triticale stubble also preserved greater amounts of soil moisture and resulted in more uniform soil moisture conditions in the 0 to 3-inch seed zone. These improved moisture conditions allow for timely planting and establishment of fall-seeded canola. Another 5-year study in Fort Collins, Colorado, also concluded that tall standing residue provides numerous benefits, including increased snow trapping; decreased decomposition rates, wind speeds, weed pressure, and soil temperatures during the fallow period; and substantially reduced within-field variation in snow cover and water storage.

These two articles discuss strategies of soil and water conservation in Pacific Northwest region: Crop Residue Management To Reduce Erosion and Improve Soil Quality and Soil and Water Challenges for Pacific Northwest Agriculture.

For questions, comments, or more information, please contact Dr. Haiying Tao (haiying.tao@wsu.edu), Assistant Professor in the Department of Crop and Soil Sciences at Washington State University.

Grain Quality Resources Page Launched!

wheat_close-up-croppedThe Wheat and Small Grains website has been updated to include a brand new page on grain quality. The Grain Quality Resources page was unveiled last month and will serve as a platform to deliver information related to the end-use quality of cereal grains.

Current information on the website includes falling number resources, the Preferred Wheat Varieties brochure, and information on some of the different market classes of wheat produced in the Pacific Northwest.

Soil Health Workshops in February

For the past 100+ years soil health has been declining across the Inland Northwest. This is not a problem just within the Inland Northwest but a global issue. Soil is the number one most important unit for sustaining agriculture production. A focus must be made to protect and enhance our productive soil for efficient and economically viable agriculture production for many generations to come.

On February 16 and 17th, soil health workshops will be held in Spokane and Walla Walla, Washington.

Soil Health HandFebruary 16, Spokane Valley

Mirabeau Park Hotel & Convention Center
1100 N Sullivan Road
Spokane Valley, WA 99037
509-924-9000

February 17, Walla Walla

The Marcus Whitman Hotel
6 West Rose Street
Walla Walla, WA 99362
509-524-5106

For more details and to register, click here. For questions and comments, contact Steve Van Vleet at svanvleet@wsu.edu or (509) 397-3290.

A Win-Win: Building Soil Health While Gaining Yield & Profit

A 375-horsepower crawler tractor pulls a 1,000-gallon tank cart and a 32-foot-wide undercutter implement during primary spring tillage plus nitrogen and sulfur fertilizer injection in May. The undercutter’s narrow­-pitched and overlapping wide V-blades slice beneath the soil at a depth of five inches to completely sever capillary channels and halt the upward movement of liquid water to retain seed-zone water in summer fallow for late-summer planting of winter wheat. Most of the winter wheat residue from the previous crop is retained on the surface to control wind erosion.

Soil health and soil quality are two synonymous terms that are defined interchangeably by the Natural Resources Conservation Service (NRCS) as follows: “Soil health, also referred to as soil quality, is the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans”. As a complicated bioecological system, soil is a living system with an abundance of diverse bacteria, fungi, and other microbes that have significant effects on soil physical and biological properties. Healthy soils provide a healthy physical, chemical, and biological environment for optimal crop growth.

Inherent soil properties that contribute to soil health, such as soil texture, are determined by the natural parent material and the environmental conditions during soil formation, in the absence of human impacts. Soil health is dynamic, rather than static, and can be degraded or improved with time as a result of soil use and management by humans. Soil degradation causes soil organic matter, fertility, structure, and biodiversity to decline and soil acidification to increase. As a result, crop productivity can decrease, crop diseases and weed problems can increase, and environmental quality can suffer.

Building soil health is becoming increasingly important worldwide. Soil imbalances in essential crop nutrients can be addressed by applying fertilizer and organic amendments. And soil chemical, physical, and biological properties can be significantly improved by adopting management practices such as no-tillage or reduced tillage.

A recently published article, Best Management Practices for Summer Fallow in the World’s Driest Rainfed Wheat Region, compares the effects of three fallow management practices on soil water dynamics, wheat stand establishment, grain yield, and economic returns. This research was conducted on two farms in the driest rainfed wheat production region in Washington (WA). At the drier site, results from the 5-year study indicated that late-planted winter wheat on no-tillage fallow was as profitable as on tilled fallow. Additionally, the study found that, at the slightly wetter site, undercutter tillage resulted in equal or greater grain yield compared with both traditional tillage and no-tillage.

Another recently published article, Wheat Farmers Adopt the Undercutter Fallow Method to Reduce Wind Erosion and Sustain Profits, surveyed 47 farmers who had been practicing undercutter tillage for several years. Farms were located in the low-rainfall (< 12 inches annually) zone of east-central WA and north-central Oregon (OR). Interviewers asked farmers to compare the agronomic and economic performance between undercutter tillage and conventional tillage. Results of this survey concluded that, on average, undercutter and conventional tillage systems have equal profitability. However, the undercutter system offers a costless air quality gain and a soil health benefit in terms of reducing wind erosion.

For questions or comments, contact Dr. Douglas L. Young (dlyoung@wsu.edu), Professor, in the School of Economic Sciences, or Dr. Bill Schillinger (William.schillinger@wsu.edu), Professor, in the Department of Crop and Soil Sciences at the Washington State University.

 

The 2016 WSU Weed Control Report Has Arrived!

Photo courtesy of graduate student John Spring.

Photo courtesy of graduate student John Spring.

The 2016 WSU Weed Control Report is now available on the Wheat and Small Grains website. The annual report summarizes the results from field studies conducted by Ian Burke, Drew Lyon, and their staff. Financial support for the studies was provided by the Washington Grain Commission, the USA Dry Pea & Lentil Council, the Mel & Donna Camp Endowment, and by several agrichemical companies. The research was conducted in winter wheat, spring wheat, chemical fallow, grasslands, alfalfa, chickpeas, and dry pea.

Weeds investigated in 2016 included rattail fescue, mayweed chamomile (a.k.a. dog fennel), catchweed bedstraw, rush skeletonweed, Russian-thistle, common lambsquarters, wild oat, Italian ryegrass, downy brome, smooth scouringrush, and volunteer buckwheat. Two studies looked at Talinor, a new herbicide from Syngenta, in winter wheat. Several studies were conducted in chickpea to look at pyridate, previously sold as Tough herbicide, and paraquat applied at the cracking stage. Neither option is currently labeled for use in chickpea, but you can see what the potential for these treatments are. Data from these studies may be used to help support possible labeling in the future.

In addition to the 2016 report, annual reports dating back to 2013 are on the Wheat and Small Grains website.

For questions or comments, contact Dr. Drew Lyon at drew.lyon@wsu.edu or 509-335-2961.

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