Wheat is mostly ending flowering across Maryland now, except for some late-planted fields. The FHB prediction map shows enhanced FHB risk. If your wheat flowered within the past 4-7 days, you are still in the window for FHB fungicide application. This season, we are also observing several foliar diseases such as stripe rust, powdery mildew, BYDV, and tan-spot in our variety trial plots. Some farmers are also reporting these issues from their fields. If you are considering the application of fungicides at this stage, use FHB fungicides: Miravis-Ace, Prosaro, Prosaro-Pro, or Sphaerex. These will control other fungal diseases, in addition to FHB, but not BYDV. For BYDV none of the fungicides can provide control, as it is a viral disease. Genetic resistance is the only real solution for BYDV. Strobilurin-containing fungicides are not recommended for application at this stage.

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

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

Winter wheat development in Michigan ranges from flag leaf to boot stage, with flowering expected within the next week or two. Leaf diseases have been minimal to date, with only limited reports of powdery mildew, Septoria blotch and leaf rust. To date stripe rust has not been reported in Michigan. 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. Fungicides applied for head scab management will also provide protection of the flag leaf.

Winter barley is heading in central Michigan. The Fusarium Risk Assessment Map currently shows low risk, however moisture may increase risk potential. Fungicides for management of head scab should be applied once heads have fully emerged, up to 7 days post head emergence, with recent research demonstrating 4 days post head emergence being optimal for head scab and DON suppression. Fungicides applied for head scab suppression will also assist in protecting the foliage.

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

Wheat and barley disease management discussion for 2023 is posted here: www.youtube.com/watch?v=I-TanpnqtEE&t=59s

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

Winter malting barley heads are beginning to emerge from the boot in fields across New York State. 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 barley and 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 (especially scald) in the upper canopy based on scouting of individual fields. There is an application window of approximately 7 days starting at full head emergence of barley in which reasonable FHB and DON suppression can be expected. Though the calculated risk of FHB infection is currently low, the risk level may change in following days. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently.

Winter wheat will begin flowering (yellow anthers visible) later this month, so be sure to monitor this site and your wheat fields from now into early June to make a fungicide spray decision on that crop.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University

With the abnormal twists and turns in the weather, where we had the past few weeks as dry and hot, this week starting from the weekend has been pretty wet and cool. The weather has provided some relief to the drought-like conditions that the wheat plants were showing the last week. However, this weather is also conducive to FHB development, especially in the susceptible varieties. Wheat is currently flowering across the state of Maryland. Flowering is when yellow anthers emerge out of the wheat spikes. If you have planted a susceptible variety for FHB, you should consider applying FHB fungicides. If you are planning to apply fungicides for FHB, remember that triazole-containing fungicides (Miravis-Ace, Prosaro, Prosaro-Pro, and Sphaerex) should be used for controlling FHB. They can control other fungal pathogens like powdery mildew, rusts, in addition to scab. Strobilurin-containing fungicides should not be used at this stage. These fungicides do not need to be tank mixed with anothe r product for spraying. The fungicide products should be applied at the full rate recommended by the manufacturers. 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

Scab infection risk is likely to increase next week across the southern portion of PA as a result of increased precipitation chances. Most wheat has not yet headed, but if your barley or wheat in high risk areas is heading and approaching flowering, stay alert and consider a fungicide application for susceptible cultivars. 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-mount ed 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

Wheat is currently flowering or will soon flower across the state of Maryland. Flowering is when yellow anthers emerge out of the wheat spikes. This is again that year, in which if you planted a resistant variety, you would be okay without spraying fungicides for controlling Fusarium head Blight (FHB risk map: top picture). However, if your planted variety is not FHB resistant, you should consider application of FHB fungicides (FHB risk map: lower picture). If you are planning to apply fungicides for FHB, remember that triazole-containing fungicides (Miravis-Ace, Prosaro, Prosaro-Pro, and Sphaerex) should be used for controlling FHB. They can control other fungal pathogens like powdery mildew, rusts, in addition to scab. Strobilurin-containing fungicides should not be used at this stage. 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. Aerial application at a ra te 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

Wheat on the Eastern shore of Maryland is heading and should start flowering within a week or so. Wheat in the north-western part (Frederick, Carroll, Hartford counties) is also close to heading or has started heading. Barley is already headed or is currently heading, depending upon the location and the variety. The FHB fungal pathogen infects the wheat plants at the flowering stage (when the yellow anthers emerge from the heads), which is the stage at which the application of fungicides is conducted in wheat. The FHB map currently does not show high risk, especially for a genetically resistant variety. However, keeping an eye on the forecasts and weather patterns over the next few days as your wheat flowers is recommended. If you are planning to apply fungicides for FHB, remember that triazole-containing fungicides (Miravis-Ace, Prosaro, Prosaro-Pro, and Sphaerex) should be used for controlling FHB. They can control other fungal pathogens like powdery mildew as well, in addition to scab. Strobilurin-containing fungicides should not be used at this stage.

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

Wheat is at or past flowering in much of North Carolina, and near flowering in the northeast part of the state. Scab risk remains very low here and in surrounding states. Given the extended period of dry, warm weather that lies ahead, scab is unlikely to be a problem for growers of wheat or barley in this state. At this time, no fungicide is needed for scab management in small grain crops in this area.

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

Barley is heading across the region, but scab risk is fairly low for all except those growing very susceptible varieites in western PA. If you missed a fungicide application at full heading, there is great news: we have recently revised our recommendations regarding fungicide timing. Work done by researchers in North Carolina found that the best spray timing for protecting winter barley from scab is application six days after 100 pct heading. With this new guidance we should get better DON reduction in barley than under our previous recommendation which targeted 50 pct heading. Current labels state that the last stage of application is mid-flower and there is a 30-day harvest restriction. Do not use any of the strobilurins (Quadris, Headline), or strobilurin/triazole (Twinline, Quilt, Stratego) combination products at flowering or later. There is evidence that they may cause an increase in mycotoxin production.

Miravis Ace, Prosaro, Prosaro Pro, and Sphaerex all provide very good scab suppression. The Miravis Ace label allows for earlier application than Caramba or Prosaro, but best results are still achieved when application is timed after full heading in barley. 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

Wheat fields in Kentucky are now at anthesis (Feekes 10.51) or fast approaching it. Currently, most of the state is under “low risk” for FHB for susceptible to moderately resistant varieties; however, for very susceptible varieties, some areas are in a medium to high risk, with predictions of risk to increase over the next two days. For in-season management of FHB, it is important to apply a fungicide with efficacy against FHB. The most recent edition of the “Fungicide Efficacy for Control of Wheat Diseases” publication is available on the Crop Protection Network (https://cropprotectionnetwork.org/publications/fungicide-efficacy-for-c…), which provides information on efficacy of fungicides for control of FHB and other diseases. For FHB management with fungicides, it is important to apply at Feekes growth stage 10.51 up to about 6 days after for the greatest protection against FHB.

--Dr. Carl A. Bradley, Professor and Extension Specialist, University of Kentucky