Scab risk across the majority of PA remains low early this week, a result of unseasonably cool temperatures. However, for barley that is now heading in western PA, a protective fungicide application may be advised for susceptible or very susceptible varieties. Barley growers in the northern tier of PA should keep an eye on their crops for heading as current weather forecasts predict higher risk for those areas in the near future. Check your risk level any time at www.wheatscab.psu.edu.

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

Head scab risk has been low across North Carolina. Wheat throughout the state is either well past flowering or, in the far northeast, at least at mid-flowering. For those with wheat still flowering… the risk for wheat flowering now is low because weather in the last 2 weeks has been dry. By the time the May 7-10 rain events have a chance to elevate the risk, your wheat will likely be past the vulnerable stage, which is flowering.

Wheat heads are susceptible to Fusarium infection from early flowering through about 7 days after mid-flowering. Fungicides containing QoIs (strobilurins) should be avoided after flag leaf stage, as they can increase DON (AKA vomitoxin) in a scab epidemic. Miravis Ace, Prosaro, Caramba and Proline are about equally effective in reducing scab when applied at early wheat flowering and even several days later. Monitor scab risk at wheatscab@psu.edu.

--Christina Cowger, Small Grains Pathologist, North Carolina State University

In the northern counties, wheat is at heading stage with early maturing varieties approaching flowering. In the South, wheat is approaching flowering with the early maturing varieties at the flowering stage. In the eastern part of the state, wheat is at the heading stage. Currently FHB risk is predicted to be low in the state. With more showers over this weekend and late next week, FHB risk might increase. Keep checking the weather forecast and monitor FHB risk at wheatscab@psu.edu.

The recommended stage for application of fungicides on wheat is at flowering (50% of the main tillers showing yellow anthers) or within 4-7 days of that. The fungicides effective for FHB are Prosaro/ Caramba/ Miravis-Ace. The fungicide products should be applied at the full rate recommended by the manufacturers. Strobilurin containing fungicides should not be applied after flag leaf stage as they increase the risk of DON (vomitoxin) accumulation. 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° 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

Winter malting barley in New York is ahead in development compared to a year ago. Some barley heads are already emerging from the boot and this is a critical time to consider a fungicide application. The Fusarium Risk Assessment Map (www.wheatscab.psu.edu) today indicates a low risk of Fusarium head blight (FHB) for most areas of New York, primarily based on lower temperatures. It is important within the Risk Tool to select an appropriate level of resistance for your variety. Calculated risk increases dramatically in very susceptible compared to susceptible varieties; varieties currently being grown in NYS typically range from susceptible to moderately susceptible. Rain showers are in local forecasts over the next week; duration of leaf/head wetness is more important for FHB development than is the amount of precipitation. Maximal suppression of FHB and grain contamination by deoxynivalenol (DON) mycotoxin results when fully emerged heads of winter malting barley are sprayed with DMI (FRAC Group 3) containing fungicides Caramba, Prosaro, or Miravis Ace (latter includes FRAC Group 7 fungicide). A heads-emerged spray with these fungicides also protects upper leaves against fungal leaf blotches, powdery mildew, and rusts. Foliar sprays of any of these three products up to seven days after head emergence may still result in significant FHB and DON suppression. Fungicide products containing QoI (FRAC Group 11) fungicides should not be applied to headed wheat or barley as they may result in increased levels of DON in grain.

Winter wheat is generally a week or more behind in development from winter barley planted on the same fall date. Winter wheat in New York varies from stem elongation to flag leaf visible stages. We should reach the critical fungicide application window for winter wheat over the next few weeks. Wheat varieties being grown in New York vary from moderately susceptible to moderately resistant. The DMI (FRAC Group 3) containing fungicides Caramba, Prosaro, or Miravis Ace (latter includes a FRAC Group 7 fungicide) are the most effective fungicides for suppression of FHB and DON contamination when applied at flowering (emergence of yellow anthers on heads). A flowering application of these fungicide products should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rusts, and fungal leaf blotches in the upper canopy based on scouting of individual fields. Powdery mildew has been observed in mid-canopy in some fields. There is an application window of a pproximately 7 days from the beginning of flowering in which reasonable FHB and DON suppression can be expected. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently as your winter wheat crop approaches heading and flowering.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University

Wheat in Southeastern and South Central portions of Kansas are heading and flowering this week. The risk of severe head blight is low currently. Parts of these regions received multiple rain showers this week. The risk of disease could increase rapidly if moisture returns later this week.

--Erick DeWolf, Plant Pathologist, Kansas State University

Several wheat fields in Kentucky currently are at the early anthesis stage (Feekes growth stage 10.51) or beyond that stage. Currently, the FHB risk map is showing a medium risk for FHB in some areas of Kentucky. With rainfall in the forecast in the upcoming days, this risk may increase and encompass a larger geography. Because of rainfall, soil is saturated in several fields, making it difficult for ground sprayers to apply fungicides. It is important to note that multi-state research trials have shown that effective fungicides registered for FHB control in wheat have been effective in reducing FHB and the associated mycotoxin DON when applied up to 7 days after the early anthesis stage. Please read all fungicide labels before making any applications to ensure that your crop is still at a stage where fungicides can be applied.

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

Welcome to the 2021 Fusarium Head Blight Prediction Center. The Prediction Center was renovated this past year and you may need to refresh your web browser to enjoy some of the new features. Please take a few minutes to familiarize yourself with the locations of help documents (“?” Button), assessment date selection (calendar), and model selection tools (menu button in the upper left).

The Prediction Center is currently focused on an KS, MO, IL, IN, MD, DE and Northern VA. Wheat in parts of these states likely approaching the flowering stages of growth when the crop is most vulnerable for infection by the Fusarium fungus. Currently, the risk maps indicate the risk is low in most areas of country. There are a few areas of moderate risk developing in Southern IL and Southern MO.

--Erick DeWolf, Plant Pathologist, Kansas State University

I hope that you all are staying safe and are vaccinated by now. Wheat season of 2021 is on and we will be providing the FHB risk assessment commentaries regularly to the small grain community throughout the wheat and barley flowering season of 2021. This is the first update in the series.

Hopefully, you selected a resistant wheat variety for your planting this year after referring to the University of Maryland’s FHB evaluation of wheat varieties. A good start goes a long way in managing FHB.

Wheat in the Eastern shore of Maryland is either at jointing to heading stage and should start flowering within a week or so. Barley, however, is already heading or will be soon heading in this part of the state. It is important to note that the correct stage for spraying fungicides on wheat is at flowering (when the yellow anthers start to show on the heads), whereas on barley it is at heading (when the heads emerge from the boots). Even with some intermittent showers, the FHB risk is currently predicted to be low across the state. However, with the rain forecast for this week, the risk may soon escalate. The right fungicides for FHB are Prosaro, Miravis-Ace or Caramba at the right stage of the crop. Fungicides containing strobilurin should not be applied for control of FHB, as in multiple university research trials, strobilurin fungicides have been shown to increase DON levels in grain. On the western side of the shore in Frederick, Harford and nearby counties, wheat plants are st arting to joint, and are not at a stage prone for FHB.

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

Barley is now heading across the southern tier of Pennsylvania. Keep a watchful eye on your crop, and if you plan to spray for head scab, target a fungicide application when 50% of the barley stems in the field are fully headed. Caramba, Prosaro and Miravis Ace give good control of most leaf and head diseases, in addition to suppressing scab. Spray nozzles should be angled at 30° down from horizontal, toward the grain heads, using forward- and backward mounted nozzles or nozzles with a two directional spray, such as Twinjet nozzles.

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

--Director, Southeast Agricultural Research & Extension Center Associate Professor, Plant Pathology and Environmental Microbiology

Head scab risk remains low across most of North Carolina. For wheat flowering today, risk is LOW throughout North Carolina EXCEPT it is medium in Dare County and pockets of the counties north of the Albemarle Sound. Wheat heads are susceptible to Fusarium infection from early flowering through about 7 days after mid-flowering. Fungicides containing QoIs (strobilurins) should be avoided after flag leaf stage, as they can increase DON (AKA vomitoxin) in a scab epidemic. Miravis Ace, Prosaro, Caramba and Proline are about equally effective in reducing scab at early wheat flowering and even several days later. None of those products, including Miravis Ace, is as reliably effective in suppressing scab if applied before flowering, e.g., at 50% heading. In other words, better a little late than early with scab-targeted fungicide applications. Monitor scab risk at wheatscab@psu.edu.

-- Christina Cowger, Small Grains Pathologist, USDA-ARS and North Carolina State University

For more details, go to the FHB Risk assessment tool at http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab Initiative, go to https://www.scabusa.org