This week's update is NOT a carbon copy of last week; while the fields still are all but void of disease and pests of any kind, the immediate weather forecast is not. Extreme heat is forecasted for the southern half of the state. Luckily, the grainfill period is well underway for the spring cereals and near completion for the winter cereals. The risk of yield losses caused by fungal diseases is very limited at this stage of the game. Fusarium head blight infections can still occur and, consequently, deoxynivalenol (DON) can still accumulate in the grain. However, the FHB risk models indicate low risk across the southern half of the state.

In the northern part of the state, the situation is not the same. In the southern half of the Red River Valley, about half the spring wheat crop just reached anthesis this past week. Spring wheat in the northern half of the Red River Valley will start to reach anthesis this week. And while daytime highs are not predicted to be as extreme as those in the southern half of the state, dew points are forecasted to be in the mid-to-upper sixties and even low seventies across the state through the 4th of July weekend. That means not only hot and muggy conditions during the day, but also much higher nighttime temperatures at night. This will result in much longer leaf wetness duration periods. The risk models for all the diseases, including FHB, will start to trend higher.

Up to this point, the fields are all but void of fungal diseases. The risk of economic damages from leaf rust, Septoria, or tan spot is small at this point, even with the increased risk of infection. This is simply a function that no inoculum (spores) is around to cause infections. That is not the case for FHB. Early research with spore traps following the outbreaks in 1993 and 1994 taught us that it is safe to assume that FHB spores are always around. Subsequent research showed that concentrations in the field are highest when the previous crop was a host for Fusarium graminearium. Corn harvested for grain in combination with reduced tillage was the worst-case scenario.

Therefore, the advice this week for most of Minnesota is as follows:

Oats - If you did not apply a fungicide to control crown rust when the flag leaf had just fully extended, apply a fungicide at Feekes 10.5 (fully headed) to protect the crop against crown rust for the remainder of the season. Switch to a premium fungicide to also try to suppress FHB if corn harvested for grain was the previous crop.

Spring barley - Apply a fungicide at Feekes 10.5 (fully headed) to suppress FHB and control net blotch on varieties rated susceptible or very susceptible to net blotch. Switch to a premium fungicide to also try to suppress FHB if corn harvested for grain was the previous crop.

Winter wheat - Apply a fungicide at Feekes 10.51 (beginning of anthesis) if you find either tan spot or Septoria present in the lower canopy or your variety is rated susceptible or very susceptible to FHB (a rating greater than 4). Switch to a premium fungicide if corn harvested for grain was the previous crop.

Spring wheat - Apply a fungicide at Feekes 10.51 (beginning of anthesis) if you find either tan spot or Septoria present in the lower canopy or if your variety is rated susceptible or very susceptible to FHB (a rating greater than 4). Switch to a premium fungicide if corn harvested for grain was the previous crop.

A band that stretches across the southern third of Roseau County, the eastern half of Marshall County, and the northern half of Pennigton County has received more rain this month than other parts of the Red River Valley. Both the national and the NDSU risk model for FHB indicate moderate risk for moderately susceptible spring wheat varieties and high risk for very susceptible varieties at this point already. This warrants that producers switch to a premium fungicide regardless of the variety's resistance rating or previous crop in the coming days and through the July 4th weekend.

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

The earliest planted spring wheat, spring durum and spring barley began to head and flower last week. Right now, scab risk for moderately susceptible varieties is greatest for a pocket in NW and NE North Dakota. For susceptible varieties, scab risk is elevated for the northern half of North Dakota, with localized pockets of risk in the southern half of the state. Moderately resistant levels still are estimated to have low scab risk at this point in time. Humidity levels have started to increase (and when combined with isolated thunderstorms) will increase scab risk for most areas of ND throughout the Fourth of July weekend. With the wide range of planting dates this year, I am expecting small grains will be heading and/or flowering into mid to late July.

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

Most wheat has finished flowering and is now moving into the milk stage. Conditions have been favorable for FHB, but there is low incidence and low severity in fields scouted. A few symptomatic heads are shown here. Inoculated wheat nurseries under mist irrigation show severe incidence and moderate severity.

--Camilo H. Parada Rojas, Assistant Professor, Field Crops Pathology Lab, Cornell University

Welcome to the Fusarium Head Blight Prediction Center. These tools provide daily estimates of disease risk for wheat in the central and Eastern US. The focus of the disease forecasting effort shifts to some northern states this week including parts of South Dakota, Minnesota, Michigan and New York. Wheat in these parts of the country should be approaching the heading, flowering and early stages of grain development that are most vulnerable to Fusarium head blight. The risk map is showing some moderate or high levels of disease risk for some areas in SD, MI and NY. Growers in these areas should be working with local extension personnel and other advisors to evaluate the need for fungicides to suppress disease development.

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.

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

Welcome to the Fusarium Head Blight Prediction Center. These tools provide daily estimates of disease risk for wheat in 35 states. The focus of the disease forecasting effort shifts to some of the more northern states this week including northern IN and OH, as well as southern regions of SD, WI and MI. Wheat in these parts of the country should be approaching the heading, flowering and early stages of grain development that are most vulnerable to Fusarium head blight. The risk map is showing some moderate or high levels of disease risk for areas northern IN and OH. Parts of southern WI and MI are at moderate risk for disease, while SD appears to be at low risk.

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

Wheat in the Eastern Shore of Maryland has finished flowering. Wheat in the Northern and Western parts of the state is flowering. The weather in Maryland has been a roller coaster this spring, and plants have been under stress due to late frost damage in the beginning and now due to record high temperatures this week.

The FHB risk map shows moderate levels of FHB resistance. If you have planted a susceptible variety which has just flowered last week or is flowering right now, and you have not sprayed FHB fungicides, you can still do so, as fungicide application 4-6 days after flowering is also known to provide some control. The recommended stage for application of fungicides on wheat is at flowering (50% of the main tillers showing yellow anthers) or within 4-5 days of that.

The fungicides effective for FHB are Miravis-Ace/Prosaro/Prosaro-pro/Sphaerex. These products will also control other fungal foliar diseases being observed sporadically in the fields, such as powdery mildew and rusts. These fungicides do not need to be tank-mixed with another product for spraying. The fungicide products should be applied at the full rate recommended by the manufacturers. Strobilurin-containing fungicides should not be sprayed at this stage.

If you have planted a resistant variety, the FHB risk does not seem particularly high at this moment.

--Nidhi Rawat, Small Grains Pathologist, University of Maryland

Dry and hot spring weather has been keeping scab risk low up to this point, however, some areas are at medium risk this week. While the risk map is very helpful to determine average risk across large areas, it may not always reflect precise conditions that occur in pockets of wheat production that are not well-represented by weather stations. If your wheat or barley has been experiencing showers or high humidity for a few weeks, consider a fungicide application for scab at early flowering. If you plan to spray for head scab, choose a labeled triazole-containing product (FRAC 3) like Proline, Prosaro, Prosaro Pro, Miravis Ace, or Sphaerex. Do not use a product that contains any strobilurin (FRAC 11). The Miravis Ace label allows for earlier application than other fungicides, but best results are still achieved when application is timed after full heading in barley and flowering in wheat. If weather conditions prevent fungicide application at ideal timing, an application as soon as conditions allow will still be quite effective in reducing scab and DON production. Follow labels to determine post-harvest interval constraints for the fungicide you choose. Spray nozzles should be angled at 30 degrees down from horizontal, toward the grain heads, using forward- and backward-mounted nozzles or nozzles with a two-directional spray, such as Twinjet nozzles. Additionally, a fungicide treatment at heading using any of these products will also give you excellent control of most leaf diseases as well.

Given the extreme heat across much of PA early this week, there is increased risk of phytotoxicity (including interference with pollination) as a result of untested tank mixes. Avoid including additives in your fungicide application, such as fertilizers, insecticides and adjuvants while wheat is flowering in these conditions. If a spreader or sticker is recommended, follow the fungicide label to determine the appropriate one.

--Alyssa A. Collins, Associate Professor, Plant Pathology and Environmental Microbiology, The Pennsylvania State University

Wheat across Maryland, including the Eastern Shore, is now flowering, the stage when yellow anthers emerge from the wheat heads. This is the critical window for FHB infection and the optimal timing for an FHB-targeted fungicide application. If you have planted a susceptible variety, consider an application at early flowering (when anthers are visible) or within the recommended window shortly thereafter.

With forecasted showers and thunderstorms this week, conditions are expected to become more favorable for Fusarium head blight (FHB/head scab). The FHB risk map currently indicates moderate FHB risk in the region, and it can further increase quickly over the next several days, especially in susceptible varieties, if warm, humid conditions persist.

For FHB control, use triazole-containing fungicides such as Miravis Ace, Prosaro, Prosaro Pro, or Sphaerex. These products also provide activity against other foliar fungal diseases (e.g., powdery mildew and rusts), although those are not currently a major concern. Avoid strobilurin-containing fungicides at this stage. These products do not need to be tank-mixed with another fungicide for FHB control, and they should be applied at the full labeled rate.

For best coverage of wheat heads, follow label guidance and use appropriate application practices. In general, aerial application at a rate of 5 gallons per acre or ground application at 15 gallons per acre with 300-350 um droplet size is recommended. Spray nozzles should be angled at 30-45 deg down from horizontal, toward the grain heads, using forward- and backward-mounted nozzles or nozzles with a two-directional spray, such as Twinjet nozzles.

--Nidhi Rawat, Small Grains Pathologist, University of Maryland

Barley is heading in the southernmost regions of Pennsylvania. Be sure to scout for growth stage as there appears to be a good deal of variability across the region due to the dry fall and spring. Risk of scab infection is medium in many Southeast areas now, but keep an eye on your risk forecast as your crop approaches heading.

The best fungicide application window for barley is from 100% heading up to a week later. If you plan to spray for head scab, choose a labeled triazole-containing product (FRAC 3) like Proline, Prosaro, Prosaro Pro, Miravis Ace, or Sphaerex. Do not use a product that contains any strobilurin (FRAC 11).

--Alyssa A. Collins, Associate Professor, Plant Pathology and Environmental Microbiology, The Pennsylvania State University

Most wheat across the state has reached or is entering flowering. Dry conditions accelerated development in many fields, resulting in earlier heading, shorter plants, and somewhat reduced head size. Rainfall over the weekend was much needed but uneven. The Eastern Shore received up to ~0.75 inches, while parts of the Middle Peninsula and Northern Neck received only ~0.25 inches.

A freeze event about one week ago is now beginning to show symptoms in some fields. Growers should scout approximately 7 days after the freeze to distinguish head bleaching caused by freeze injury from symptoms that may develop later due to Fusarium head blight (scab).

The current FHB risk is moderate, with additional rain in the forecast. The highest risk fields are those planted into corn stubble with susceptible varieties. With variable yield potential and recent weather patterns, fungicide decisions should be made on a field-by-field basis, prioritizing fields with strong yield potential or contractual obligations. Fungicide applications are most effective when applied at early flowering (Feekes 10.5.1).

--Douglas S. Higgins, Assistant Professor and Extension Specialist, Virginia Tech Eastern Shore Agriculture Research and Extension Center