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Wheat & Small Grains Blythe Howell

Eastern Oregon Disease Update March 2017

OW7Michael D. Flowers, Dept. of Crop and Soil Science
Oregon State University, 107 Crop Science Building, Corvallis, Oregon 97331-3002
T 541-737-9940 | F 541-737-1589 | Mike.Flowers@oregonstate.edu

March 16, 2017

To: Oregon Wheat Growers and Industry Reps
From: Mike Flowers, Larry Lutcher, Christina Hagerty and Chris Mundt; OSU
RE: Eastern Oregon Disease Update

Stripe Rust

Stripe rust was found on multiple varieties at the Lexington and Walla Walla variety testing locations. Early stripe rust infections appear to be spread throughout eastern Oregon and southeastern Washington. Growers are encouraged to scout their fields and tank mix a fungicide with their spring herbicide if stripe rust is present in their field and/or they are growing a highly susceptible variety (Mary, Brawl CL+, SY Ovation, ORCF-102 are examples).

Winter Injury and Snow Mold

Winter wheat fields throughout the region are showing symptoms of winter injury and/or snow mold. Winter injury symptoms are typically mild (burned leaf tips and yellow foliage) and plants will grow out of these symptoms as the weather warms. Snow mold symptoms (white or pink mycelial growth) are present in many fields but are spotty. Use a disc drill to fill in gaps, holes, or blank spots created by snow mold damage if affected areas continue to look questionable or fail to recover. Decisions to “sweeten-up” fields (or not) should be made quickly (in the next 4 to 10 days, depending on location).

To view this report in PDF format, click here.

 

Metalaxyl-resistant Pythium

Metalaxyl 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. 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

The 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 by email at kantors@wsu.edu at the Center for Sustaining Agriculture and Nature Resources, Washington State University, or Kathleen Painter by email at 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… » More ...

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.

 

Adjusting Wheat-Based Management Strategies for Oilseed Production

Field of canola.

Oilseeds, such as canola, are recognized as rotational crops that can benefit the agro-ecological and social-ecological systems within the traditional wheat-based cropping region of the inland Northwest Pacific. Although farmers can continue to use wheat-based farm equipment, management practices need to be adjusted specifically to canola physiology and morphology to optimize yield and quality.

A recently published article, Physiology Matters: Adjusting Wheat-Based Management Strategies for Oilseed Production, compares the physiological and morphological characteristics between wheat and oilseeds. Characteristics studied included the differences in seed size, shoot meristem, cold tolerance, and above and below ground morphology. Based on these differences, the article provides recommendations for modifying wheat management strategies, for example, planting date and fertility management, for canola production.


For questions or comments, contact Dr. William Pan at wlpan@wsu.edu or Karen Sowers at ksowers@wsu.edu.

First Stripe Rust Update of the 2017 Season – January 2017

As many of you know, the 2016 crop season was very favorable for stripe rust due to the mild winter and early spring with temperature and moisture conditions that were favorable for rust development. In some cases, this resulted in severe rust in fields planted to susceptible varieties and/or multiple fungicide applications to limit rust… » More ...

Dark Northern Spring

‘DNS’ is a common term when referring to the production of hard red spring wheat. Around the coffee shop you may hear your neighbor say, “I’m growing DNS.”

What is DNS? DNS is short for ‘Dark Northern Spring’ –and what is that?

Under the Official United States Standards for Grain, the market class ‘Hard Red Spring wheat’ is divided into three subclasses: Dark Northern Spring wheat, Northern Spring wheat, and Red Spring wheat.

What differentiates the sub-classes? It is the percentage of “dark, hard, and vitreous kernels”. To be classed as Dark Northern Spring wheat, the sample must have 75 percent or more dark, hard, and vitreous kernels. The limits for Northern Spring wheat are more than 25% but less than 75% dark, hard, and vitreous kernels; and Red Spring wheat has less than 25%.

Beyond the official market classification, the grain trade may impose any number of additional criteria. For example, to receive top prices, ‘DNS’ often must have a minimum of 14% protein. Some elevators may discount grain below this threshold with a sliding scale and may reward higher protein levels with premiums.

The Standards harken back to a time when analyzing protein was slow and laborious. In a very general sense, the percentage of vitreous kernels is correlated with protein content. And so at one time, a quick visual assessment of the percentage of vitreous kernels was a reasonable proxy for protein content. Why protein so important? Generally speaking, protein content has a direct relationship to gluten content, and as you may know, gluten is the visco-elastic (rubbery) material that allows us to make light airy yeast-leavened bread. I often refer to gluten as the ‘horsepower’ of wheat and so from bakers to millers to the elevator to the producer, higher protein is usually rewarded with premium prices because of its greater performance and value.

For more information contact Dr. Craig F. Morris, Director USDA-ARS Western Wheat Quality Laboratory, at morrisc@wsu.edu or 509-335-4062.

Washington State University