Wheat across North Carolina is approaching or in boot stage, so it is time to think about head scab (Fusarium head blight). Wheat heads can be infected by Fusarium at flowering. The risk forecasting tool estimates scab risk for wheat flowering on the day that you select (www.wheatscab.psu.edu). At the moment, most of North Carolina has low risk for scab, which makes sense because across the state, we are in moderate to extreme drought.

High relative humidity and mild temperatures increase risk, so watch out for rain as your wheat approaches heading. If risk becomes moderate to high, the best time to apply fungicide to wheat is early- to mid-flowering or even a few days later. In winter barley, the best time for a scab-targeted fungicide is around 6 days after 100% head emergence. Scab is not effectively managed by fungicide applications prior to flowering in wheat and full heading in barley. The most effective fungicides for scab reduction are Miravis Ace, Prosaro Pro, and Sphaerex. Do not apply strobilurin-containing products after flag leaf.

For wheat planted with conventional tillage, low scab risk means a fungicide is unlikely to be profitable. For wheat planted no-till, especially into corn debris, a fungicide may be profitable even if forecasted risk is low. Variety resistance is also important in deciding whether to spray. For a wheat variety's scab resistance level, visit the NC OVT site: https://ncovt.medius.re/wheat. Find your variety and scroll down to Disease Ratings.

--Christina Cowger, Small Grains Pathologist, USDA-ARS, NC State University

Welcome to the Fusarium Head Blight Prediction Center. These tools provide daily estimates of disease risk for wheat in 35 states. The risk map is showing some moderate levels of disease risk for areas along the Mississippi River in LA, MS, AR and TN. Most wheat in this area is unlikely to be at heading and flowering stages of growth that are most vulnerable to the disease.

Tips for using the risk maps:

The tool shows the disease risk for susceptible wheat varieties for today's date. Clicking on the map will activate graphs that display a 14-day summary of weather and disease risk for the selected location. 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 use the menu button on the upper left to view risk maps for wheat varieties with different levels of genetic resistance to Fusarium head blight. This menu also provides options for viewing additional map features or restricting area displayed to just the major wheat production areas.

The risk model was updated for the 2026. This update better accounts for recent research observations gather across the country. Unlike in previous years, the new model no longer requires users to specify whether they are interested in spring or winter wheat. Instead, the model focuses on weather conditions that consistently favor disease development across all classes of wheat.

--Erick DeWolf, Plant Pathologist, Kansas State University

The Fusarium Head Blight Prediction Center is active for the 2026 growing season. These tools provide daily estimates of disease risk for wheat in 35 states. The tool shows the disease risk for susceptible wheat varieties for today's date. Clicking on the map will activate graphs that display a 14-day summary of weather and disease risk for the selected location. 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 use the menu button on the upper left to view risk maps for wheat varieties with different levels of genetic resistance to Fusarium head blight. This menu also provides options for viewing additional map features or restricting area displayed to just the major wheat production areas.

The risk model was updated for the 2026. This update better accounts for recent research observations gather across the country. Unlike in previous years, the new model no longer requires users to specify whether they are interested in spring or winter wheat. Instead, the model focuses on weather conditions that consistently favor disease development across all classes of wheat.

--Erick DeWolf, Plant Pathologist, Kansas State University

Wheat in much of the country is now past the growth stages that are most vulnerable to Fusarium head blight. The daily updates of the risk maps will end soon. However, the maps from earlier in the 2025 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 2026.

--Erick DeWolf, Plant Pathologist, Kansas State University

It isn't hard to find Fusarium Head Blight (FHB) or Bacterial Leaf Streak (BLS) across much of Minnesota.

BLS is appearing relatively late in the grainfill period, and yield losses caused by the disease will be relatively small.

The same cannot be said for FHB, as the conditions continue to favor disease development. The best time to assess how many early infections occurred is probably this week. These early infections result in the characteristic tumbstone kernels. These tombstone kernels can be easily removed during combining, and it is the simplest and cheapest way to reduce the amount of deoxynivalenol (DON) in the harvested grain. Unfortunately, it's too early yet to see if the current stretch of favorable conditions will result in many late-season infections. Late-season infections are more difficult to deal with as the infected kernels have a near-normal appearance and weight but contain enough deoxynivalenol (DON) to result in discounts or rejections at the point of sale.

Finally, armyworms are at treatable levels along the eastern beach ridge of the Red River Valley. The threshold to treat army worms is 4 to 5 larvae per square foot, any time before harvest. Be cognisant of the preharvest interval (PHI) for your insecticide of choice, as many products labeled for use against armyworms have a PHI of 14 days or more.

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

The focus of the forecasting models is currently on the spring wheat crop in northern ND, and MN this week. Although most of the wheat in these states is likely past the vulnerable stages of growth for Fusarium infection, there may still be some late planted fields that are still at risk.

The maps of disease risk indicates that the probability of severe head blight is low for most of ND today. However, there are a few areas of moderate and high risk in northern ND and MN. Growers in this area should be monitoring the situation more closely.

Tips for using the risk tools:

By default, the maps 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. Clicking on the map will activate graphs that display a 14-day summary of weather and disease risk for the selected location.

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 restricting area displayed to just the major wheat production areas.

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.

--Erick DeWolf, Plant Pathologist, Kansas State University

The scouts reported that many of the wheat fields they visited last week had reached anthesis. They continue to find low levels of tan spot, wheat stem maggot, cereal aphids, and Barley Yellow Dwarf Virus (BYDV). The scouts also reported some incidences of Bacterial Leaf Streak (BLS) for the first time this year. I expect the latter to worsen over the next week as the high winds that accompany the scattered thunderstorms provide the means for the disease to spread rapidly. Likewise, the risk of FHB is forecasted to increase in the southwestern and northwestern portions over the next days. As a consequence of the hit-and-miss nature of these rain events, both the NDAWN disease forecasting and the national risk model might be overestimating the risk for some of your fields if last week's rains kept missing your fields and fields are much drier (and therefor less likely to accumalate the needed leaf wetness duration periods) than estimated by the tools when the tools extrapolate the data from the data collection points to your fields in the coming days.

For oats and barley that will be reaching Feekes 10.5 (or fully headed), use a fungicide labeled for the suppression of FHB. Likewise, apply a fungicide labeled for the suppression of FHB in wheat when the crop reaches Feekes 10.51 (or beginning of anthesis). Choose one of the premium fungicide products when your variety has an FHB rating of susceptible to very susceptible (>6 or higher).

This will likely be the last issue of this season's small grains disease and pest update unless things dramatically take a turn for the worse. Have a bountiful and safe harvest!

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

Diseases: Last week, the scouts continued to find a few fields with tanspot at low incidence and severity. Widespread rains across much of Minnesota have allowed for much longer leaf wetness periods. Only the Red River Valley north of Hwy 200 continues to miss out on any measurable amounts of rain. Consequently, the conditions for developing small grain diseases, including FHB, are much more favorable for most. For oats and barley that will be reaching Feekes 10.5 (or fully headed), switch to a fungicide labeled for the suppression of FHB, as the risk forecast for the remainder of the week remains moderate to high across all but the most northern counties in NW and the most southern counties in the SW corners of the state. Likewise, apply a fungicide labeled for the suppression of FHB in wheat when the crop reaches Feekes 10.51 (or beginning of anthesis). Choose one of the premium fungicide products when your variety has a FHB rating of susceptible to very susceptible (>6 or higher)

Insects: Aphids continue to be found across Minnesota. The scouts also found the cereal leaf beetle (CLB) in Mahnomen. The economic threshold for CLB is one larva per flag leaf once the crop reaches the boot stage.

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

Diseases: Last week, the scouts continued to find a few fields with tanspot at low incidence and severity. Since last Thursday, widespread rains across much of Minnesota have allowed for much longer leaf wetness periods. Only the Red River Valley north of Hwy 200 continues to miss out on any measurable amounts of rain. Consequently, the conditions for developing small grain diseases, including FHB, are much more favorable for most. This means that the disease management/fungicide recommendations are changing compared to a week ago. For oats and barley that will be reaching Feekes 10.5 (or fully headed), switch to a fungicide labeled for the suppression of FHB, as the risk forecast for the remainder of the week remains moderate to high across all but the NW and SW corners of the state. Likewise, apply a fungicide labeled for the suppression of FHB in wheat when the crop reaches Feekes 10.51 (or beginning of anthesis). Choose one of the premium fungicide products when your variety has a FHB ra ting of susceptible to very susceptible (>6 or higher).

Insects: Aphids continue to be found across Minnesota. The numbers to date have been low, with no fields reaching the economic threshold. The scouts also found a cereal leaf beetle (CLB) larva in Norman County. The economic threshold for CLB is 3 larvae per plant before the boot stage and 1 larva per flag leaf once the crop reaches the boot stage.

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

Small grain growth stages vary in the state. The earliest seeded wheat crop is starting to head and flower, and the late-seeded crop is at the three to four leaf stage. Spring barley is also starting to head in several areas of the state. Currently, the greatest risk for FHB is on susceptible and moderately susceptible varieties in southeast North Dakota. Scattered rainstorms and higher nighttime humidity will likely increase scab risk for several areas of the state. It is possible that FHB risk will be elevated in the next 7 days for areas south of I-94.

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