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

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

Wheat in southern Maryland (Eastern shore and the western side of the bay bridge), is mostly either flowering or finishing up flowering. Incidents of extensive stripe rust have been reported from some fields in St. Mary's County and nearby counties (Courtesy: Mr. Ben Beale). Powdery mildew is also observed in the lower canopy and is moving onto the flag leaf. In addition, leaf rust is also visible in some fields. Remember that the standard FHB fungicides (Miravis-Ace/ Prosaro/ Prosaro-Pro/ Sphaerex) should be applied at this stage, as they are also effective for controlling stripe rust, leaf rust, and powdery mildew. Strobilurin-containing fungicides should not be sprayed at this stage. Even if your wheat is just 4-6 days post-flowering, it is recommended to spray the FHB fungicides. Wheat in the northern part of Maryland is also flowering/ starting to flower now. If you have planted an FHB susceptible variety and it is flowering, you may consider applying FHB fungicides.

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

With the predicted showers and thunderstorms for the majority of this week, the weather is expected to be conducive for FHB. Although the FHB risk map currently shows a low risk for head scab, the real risk may escalate in the next few days, especially for the susceptible varieties. Wheat is currently in the flowering stage on the Eastern shore of Maryland, across the state of Maryland. Flowering is when yellow anthers emerge from the wheat spikes. If you have planted a susceptible variety for FHB, you may 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 another 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

Dry spring weather has been keeping scab risk low up to this point, however, that may be shifting in some areas of PA who have experienced persistent moist conditions since the first of the month. 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 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).

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

Wheat in the Eastern Shore of Maryland is either flowering (50% of the main tillers showing yellow anthers) or will be flowering in a couple of days. This is the stage when the plants are most prone to FHB infection. Although the epidemiological models are predicting low risk currently, with the rains forecasted starting from this weekend, growers are advised to keep a close eye on the FHB risk over the coming days. In case the risk escalates, the recommended head scab fungicides are Prosaro/ Miravis-Ace/ Sphaerex or Prosaro-Pro. The applications should be made at wheat flowering or within 4-5 days after at full rates prescribed by the manufacturers. Strobilurin-containing fungicides should not be sprayed at this stage. In the northern counties, wheat is booting, and still roughly around 1-2 weeks away from flowering.

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

Barley is beginning to emerge from boot 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 patchy establishment. Risk of scab infection is low 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).

Continue to visit wheatscab.psu.edu to use the Fusarium Head Blight Prediction Center for estimating your crop's scab risk.

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

In Virginia, wheat is currently at varying growth stages across the state. On Friday April 25, many fields were at the boot stage (Feekes 9) or beginning to head (Feekes 10.1 to 10.3), while in some areas and in early maturing varieties heads have fully emerged (Feekes 10.5).

For those choosing to make a fungicide application, the optimal timing for managing scab is at early flowering (Feekes 10.5.1) and up to seven days afterward. Reminder: Do not use products that contain strobilurins (FRAC 11) to manage scab.

Warm, humid, and wet conditions leading up to and during flowering favor infection by the scab-pathogen. As of April 28, 2025, conditions in Virginia are not favorable for disease development in flowering wheat. However, for fields expected to flower in the coming days or weeks, monitor your local weather closely and consult the Fusarium Risk Tool for updates on disease-conducive conditions.

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