Wheat in much of the country is past the growth stages that are most vulnerable to Fusarium head blight. The risk maps from earlier in the 2024 season will remain available for several months so that users can review the outcomes for this year. We hope to see you next season when these tools are reset for 2025.

 

--Erick DeWolf, Plant Pathologist, Kansas State University

The risk for Fusarium head blight remains moderate to high for highly susceptible varieties for most of Minnesota through the coming weekend. The marked difference in the risk of infection between highly susceptible and moderately resistant varieties remains the same.

More info at: https://blog-crop-news.extension.umn.edu/2024/07/small-grains-disease-a…

--Jochum Wiersma, Small Grains Specialist, University of Minnesota

I took a few days off over the July 4th Holiday weekend. The risk for Fusarium head blight did not; the risk for spring wheat varieties with a rating of 6 or worse continues to be moderate to high across all of Minnesota through the end of the week. The marked difference in the risk of infection between highly susceptible and moderately resistant varieties remains the same.

More info at: https://blog-crop-news.extension.umn.edu/2024/07/small-grains-disease-a…

--Jochum Wiersma, Small Grains Specialist, University of Minnesota

Fusarium head blight (scab) risk has increased significantly for susceptible and moderately susceptible varieties across most areas of North Dakota. Risk is also elevated for moderately resistant varieties for areas in northwest, north central, and southeast North Dakota. The significant jump in risk can be attributed to higher humidity levels observed last week, in addition to longer dew periods and rain across the state. The forecast indicates several rain chances this week that will likely keep risk elevated for much of the state. There appears to be three distinct planting dates of small grains in the state: early (already flowered), middle (likely flowering this week), and late (flowering in the next 10-14 days). Right now, it looks like the greatest scab risk in the state for this season will occur this week and last into early next week.

--Andrew Friskop, Associate Professor and Cereal Extension Pathologist, North Dakota State University

Fusarium head blight risk for spring wheat varieties with a rating of 6 or worse will be high across much of the state through the end of the week. The heart of the Red River Valley is the only area with a low to moderate risk. A marked difference in the risk of infection exists between highly susceptible and moderately resistant varieties.

More info at: https://blog-crop-news.extension.umn.edu/2024/06/small-grains-disease-a…

--Jochum Wiersma, Small Grains Specialist, University of Minnesota

Fusarium head blight risk continues to remain low for most of the state. If a very susceptible variety was grown (FHB score of 7 or higher in HRSW Variety Guide), moderate to high risk exists in northeast North Dakota (Figure 1). Most of the state received rain over the past couple days, and several areas of the state will receive more rain in the coming days. The precipitation in combination with higher relative humidity values projected next week will likely increase scab risk in the state. Based on field reports, the earliest planted spring wheat is at boot to heading stages with the late planted wheat in the early leaf stages. Given the large variation in growth stages, make sure to pay attention to the weather and scab risk as the barley crop starts to head and the spring wheat and durum crop enter heading to flowering.

--Andrew Friskop, Associate Professor and Cereal Extension Pathologist, North Dakota State University

The focus of the wheat scab (Fusarium head blight) prediction effort is currently on SD, MN and ND where wheat is approaching or already at the heading and flowering stages of growth that are critical to the development of Fusarium head blight. The risk maps are currently estimating a low risk of severe disease in these regions, but growers should monitor conditions carefully for extended periods of high relative humidity that favor disease development.

Below are a few tips for using the web-based tools: The website shows the disease risk for susceptible wheat varieties for today’s date. You can select earlier assessment dates by clicking on the calendar menu at the top of the risk map.

Use the menu button on the upper left to view risk maps for wheat varieties with other levels of genetic resistance to Fusarium head blight. This menu also provides options for viewing additional map features or focusing on just areas with a high density of wheat production.

Risk maps based on 2, 4 or 6 days of forecasted weather can help users anticipate future trends in disease risk. These maps are available by selecting the 2d, 4d and 6d buttons to the right of the calendar menu.

You can activate graphs of recent weather and trends in disease risk by clicking on the base risk map. The bottom graph panel displays the disease risk for wheat varieties with different levels of genetic susceptibility to Fusarium head blight. The top graph panel displays trends in relative humidity that are conducive for disease development.S

--Erick DeWolf, Plant Pathologist, Kansas State University

Winter barley fields in New York are past the stage for fungicide treatment, and growers are getting ready for harvest in a couple of weeks. This is a good time to assess Fusarium head blight (FHB) symptoms to anticipate issues of mycotoxin contamination in grain. Barley leaf rust, powdery mildew, scald, yellow dwarf, and Stagonospora nodorum blotch have been observed in some fields, generally at low levels.

Winter wheat continues to develop ahead of most years. Harvest is projected to begin in earliest July. Most, but not all, wheat fields are past the stage when fungicide application is effective. There is an application window of approximately 7 days from the start of flowering of wheat in which reasonable FHB and DON suppression can be expected from application of fungicide products Miravis Ace, Prosaro, Prosaro Plus, or Sphaerex. The calculated risk of FHB infection currently ranges from low to high in wheat growing regions of New York, but a drying trend is expected for the next week. Be sure to check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently. Kernel soft dough stage (approximately three weeks after flowering) is an excellent time to assess wheat for symptoms of FHB and to anticipate issues of mycotoxin contamination in grain. Stripe rust has been observed in a broad area of western New York and the Finger Lakes. Powder y mildew has been more severe than usual in some varieties this season.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University

Most winter wheat fields in New York have heads fully emerged from the boot, and plants in a significant number of fields have initiated flowering (yellow anthers visible). This is a critical time for making a fungicide spray decision. The fungicide products Miravis Ace, Prosaro, Prosaro Plus, and Sphaerex are each labeled on wheat in New York and are effective in suppression of Fusarium head blight (FHB) and deoxynivalenol (DON) mycotoxin contamination. An application of these fungicide products should be based on FHB risk as well as the risks of powdery mildew, rusts, and fungal leaf blotches in the upper canopy based on scouting of individual fields. There is an application window of approximately 7 days beginning at start of flowering of wheat in which reasonable FHB and DON suppression can be expected. The calculated risk of FHB infection is currently high for wheat flowering today in several wheat growing regions of New York. Of course, the risk level may change in followi ng days. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently.

The presence of stripe rust, a potentially yield-limiting disease, in your field or vicinity is an added factor in considering a flowering-timed fungicide spray this year. The fungicides mentioned above are effective against stripe rust. Stripe rust has been confirmed in Genesee, Seneca, and Tompkins Counties this week and I suspect it is much more widespread. I urge wheat growers to scout their fields for stripe rust and to report occurrences to their field crops extension educator.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University