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

Stripe rust has been detected in several counties across Michigan, and growers are urged to scout fields. Stripe rust can develop quickly and result in significant yield loss. Be sure to scout your fields and be aware of disease pressure in your area. The goal is to keep the flag leaf as free of disease as possible throughout the flowering and grain-fill periods. To achieve this, a fungicide may be warranted during or soon after the flag leaf stage, particularly when a fast-moving disease such as stripe rust is present. If stripe rust is detected in your fields and there is still some time before a head scab fungicide application, a fungicide application now may be warranted. There are plenty of fungicide products that do and excellent job of managing stripe rust, for the complete list, see our multi-state fungicide efficacy guide: https://cropprotectionnetwork.org/publications/fungicide-efficacy-for-c….

If the crop is very close to flowering a fungicide applied at flowering to reduce risk of head scab and DON will also do a great job at providing protection of the flag leaf.

Winter wheat development in Michigan ranges from flag leaf to head emergence, 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. Fungicide products that provide good protection from head scab and stripe rust include Miravis Ace, Prosaro, Prosaro Pro, and Sphaerex. If applying fungicide products for head scab protection, don’t forget to use directional nozzles to increase coverage of the heads. 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 https://www.canr.msu.edu/field_crops/virtual-breakfast/

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

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

The current focus of the prediction effort is on areas of central IL, IN; southern OH and portions of southeastern PA 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 map indicates large areas of moderate and high risk of severe disease for much of this region. Growers in these states should consult with local University Extension or other advisors to evaluate the need for fungicide applications.

Tips of using the tool: The tool 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 restricting areas displayed.

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 map. The bottom graph panel displays the disease risk for wheat varieties with different levels of genetic susceptibility to Fusarium head blight.

--Erick DeWolf, Plant Pathologist, Kansas State University

Wheat in Maryland has either already flowered or is finishing-up flowering. The FHB prediction map shows high FHB risk. If your wheat is still in the window for FHB fungicide application (from flowering up to the following 4-7 days) you should consider the application of FHB fungicides: Miravis-Ace, Prosaro, Prosaro-Pro, or Sphaerex. These fungicides are also effective against other foliar fungal diseases such as stripe rust, powdery mildew, and tan-spot etc. Strobilurin-containing fungicides are not recommended for application at this stage.

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

Scab infection risk is high this week across the entire commonwealth as a result of increased precipitation and humidity. Risk levels subside as the week progresses in the central portion of the state, but remain elevated across the south and to the east and west. Most wheat in the south is now flowering, and if your barley or wheat in high risk areas is heading and approaching flowering, consider a fungicide application when the weather allows. 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

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