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

The focus of the forecasting models is currently on a band of the northern states extending from the South Dakota to New York. Winter wheat in this area will likely be at the flowering stages of growth that are most vulnerable to head blight over the next few weeks. The maps of disease risk indicates that the probability of severe head blight is low for most of this region today. There are some areas of moderate risk in NY and 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 Fusarium Risk Tool is showing elevated risk on the east side of the thumb, and the lower corner of SW Michigan. For the current head scab risk map please check https://www.wheatscab.psu.edu/ Foliar disease has been relatively light this season, some stripe rust and leaf rust has been detected at low levels in the state, and some areas have relatively heavy powdery mildew. Other leaf spots such as Septoria are increasing. A head scab fungicide application will also provide protection of the flag leaf from foliar diseases. For a discussion on fungicide applications see: https://www.canr.msu.edu/videos/disease-management-in-wheat-and-small-g…

--Martin Chilvers, Associate Professor, Field Crop Pathology, Michigan State University

Scab infection has increased this week across the entirety of PA (especially the central and northern regions) as a result of increased precipitation chances. If your wheat is approaching flowering, stay alert and consider a fungicide application once flowering has begun. Miravis Ace, Prosaro, Prosaro Pro, and Sphaerex all provide very good scab suppression. 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 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. Additionally, a fungicide treatment at heading using any of these products will also give you excellent control of most leaf diseases as well.

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

Flowering is finishing up across all of Maryland now, except for a few late-planted fields in the northern part of the state that may still be flowering. The FHB risk across the state continues to be high. So, if your wheat is flowering currently or has flowered within the last 4-5 days, you can still spray FHB fungicides. I have started scouting the wheat variety trials for FHB symptoms on the Eastern shore and have already started observing moderate FHB incidences in untreated plots here. The weather conditions have been conducive for FHB this season so far. If you have planted resistant varieties, the situation is expected to be better. Natural infections of leaf rust and stripe rust are also being seen sporadically. I do not expect any major losses due to these two now though. So it's okay not to spray any fungicide specifically for these diseases at this point.

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

The head scab model is currently showing low risk, however this may change with predicted moisture and warm temperatures.

Winter wheat development in Michigan ranges from flag leaf to boot stage, with flowering expected within the next week or two. Overall leaf diseases have been minimal to date, however heavy powdery mildew have been reported in areas of the state. To date stripe rust has not been reported in Michigan, however many fields have wheat streak mosaic virus that can be confused for stripe rust.

Management of head scab should start with selection of varieties with good resistance. To optimize management, fungicides may be warranted. For optimal head scab and DON suppression fungicides should be applied from the beginning of flowering up to 7 days post the beginning of flowering, with recent research demonstrating 4 days post head emergence being optimal for head scab and DON suppression. Fungicides applied for head scab management will also provide protection of the flag leaf.

Winter barley is heading in central Michigan. Fungicides for management of head scab in barley should be applied 4-7 days once heads have fully emerged.

A discussion on managing wheat and barley diseases and head scab can be found as part of our MSU virtual breakfast series https://www.canr.msu.edu/field_crops/virtual-breakfast/

Wheat and barley disease management discussion for 2025 is posted here: https://www.canr.msu.edu/videos/disease-management-in-wheat-and-small-g…

--Martin Chilvers, Associate Professor, Field Crop Pathology, Michigan State University

Wheat in Maryland is mostly either flowering or finishing up flowering. If your wheat is flowering currently, and you have a susceptible or moderately susceptible variety, it is suggested to consider fungicide application for FHB management. The recommended stage for application of fungicides on wheat is at flowering (50 pct of the main tillers showing yellow anthers) or within 4-5 days of that. As I mentioned in my previous forecast, other foliar fungal diseases such as powdery mildew, stripe rust, and leaf rust are also being seen across the state in different counties. If you plan to spray for these diseases, FHB fungicides are still recommended. Strobilurin containing fungicides should not be sprayed at this stage. The fungicides effective for FHB are Miravis-Ace/ Prosaro/ Prosaro-Pro/ Sphaerex. 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. However, if it is not flowering yet, it's a good idea to keep a watch on the weather and the FHB risk over the coming days.

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

Scab infection risk is likely to increase this week across the southern portion of PA as a result of increased precipitation chances. If your wheat is approaching flowering, stay alert and consider a fungicide application once flowering has begun. Miravis Ace, Prosaro, Prosaro Pro, and Sphaerex all provide very good scab suppression. 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 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. Add itionally, a fungicide treatment at heading using any of these products will also give you excellent control of most leaf diseases as well.

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