The Fusarium Head Blight Prediction Center estimates disease risk for wheat and barley.

Wheat in Northwestern Kansas, as well as areas of the Midwest (Central IN, IL and OH) is now at or approaching growth stages that are vulnerable to Fusarium infection. Growers in these areas should be watching weather for additional periods of humid, rainy weather that could stimulate disease. Be sure to check with local university extension or other consultants to discuss disease risk.

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. The risk maps based on 2, 4 or 6 days of forecasted weather are accessed by selecting the buttons to the right of the date selection menu. Use the menu button on the upper left corner of the map to active risk maps for wheat varieties with other levels of genetic resistance to Fusarium head blight.

Please note that the colors showing the different levels of disease risk changed this year. The lowest level of disease risk is now represented as yellow on the risk map. Moderate and high levels of risk are represented orange and red, respectively.

--Erick DeWolf, Plant Pathologist, Kansas State University

Winter Wheat is Wisconsin is in the “boot “or heading in the southern part of the state. Currently the Fusarium Risk Assessment Map is showing low risk for Fusarium head blight development. Rain is forecast for the next several days, thus, the risk is likely to climb as we approach wheat heading and flowering. Wheat farmers and consultants should pay attention to weather closely over the next several weeks as the decision to apply fungicide will need to be made during this time.

In winter wheat in Wisconsin, research has demonstrated that the best time to apply fungicides is between the start of anthesis (first anthers out) to 7 days after the start of anthesis. This same research has demonstrated that waiting to apply fungicides 5 days after the start of anthesis, optimizes deoxynivalenol (DON or vomitoxin) reductions in finished wheat. This is likely since head emergence in Wisconsin can be very uneven. Waiting 5 days after the start of anthesis may help with optimizing application timing to maximize heads flowering and receiving fungicide protection. Fungicide choice is also critical, with Prosaro, Caramba, and Miravis Ace providing the most consistent control of Fusarium head blight and reduction of DON in trials in Wisconsin. Fungicides containing strobilurin fungicides should be avoided after the boot stage of wheat as these products can increase DON levels in finished grain. Fungicide efficacy information from Wisconsin can be found at https://badgerc ropdoc.com/research-summaries/. Additional thoughts on using fungicide on wheat can be found in this Bumper Crops Video (https://youtu.be/IQeWM83QG0U).

--Damon L. Smith, Associate Professor and Extension Specialist, University of Wisconsin-Madison

Flowering is finishing up across all of Maryland now, except for a few late planted fields in the northern part of MD that may still be flowering. FHB risk across the state continues to be high. So, if your wheat is currently flowering or has flowered within 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 am already observing moderate FHB incidences in untreated plots there. 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 its okay not to spray any fungicide specifically for these diseases.

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

Over the next week, areas in the east (especially southeast) of Pennsylvania will be at the highest risk of Fusarium infection for wheat flowering at this time. Growers with susceptible or very susceptible varieties of wheat beginning to flower now should consider a fungicide treatment ahead of potential rains on Thursday. If weather conditions prevent fungicide application at early flowering, an application as soon as conditions allow will still be quite effective in reducing scab and DON production. Continue to visit wheatscab.psu.edu to use the Fusarium Head Blight Prediction Center, as your fields begin to flower.

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

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.

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

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

Now is the time to make a critical fungicide spray decision on winter malting barley. Winter barley in New York has either reached full head emergence or will do so in the next few days The Fusarium Risk Assessment Map (http://www.wheatscab.psu.edu) currently indicates a low risk of Fusarium head blight (FHB) across the state, but this could change with rain showers and thunderstorms in the forecast. 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.

Winter wheat development in New York ranges from flag leaf just visible to boot stage and is expected to initiate flowering over the next two weeks; the crop is further ahead in the Hudson Valley than in western New York. 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 Fusarium head blight (FHB) and deoxynivalenol (DON) mycotoxin contamination when applied at flowering (emergence of yellow anthers on heads). A flowering application of these fungicide products should be based on 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. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB and DON suppression can be expected. Check the Fusarium Risk Assessment Tool (http://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 growers in southern PA should watch their crops closely for heading and flowering heading into the weekend, when very susceptible varieties will be at high risk for scab infection. If you choose to spray, target your wheat crop at early flowering. 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, as your fields begin to flower.

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

With the recent showers and warming weather, FHB risk in the state is increasing. Wheat in the Eastern Shore of Maryland has finished or is just finishing flowering. If your wheat has just flowered last week, and you have not sprayed FHB fungicides you can still do so, as fungicide application 4-6 days after flowering is also known to provide some control. Wheat in the Northern parts is either flowering/ will soon start flowering. The FHB risk for this part of the state (Frederick, Carroll and Harford counties) is predicted to be moderate to high, especially if the wheat variety planted is susceptible. If the planted variety is resistant, the risk is not predicted to be particularly high. The recommended stage for application of fungicides on wheat is at flowering (50% of the main tillers showing yellow anthers) or within 4-5 days of that. The fungicides effective for FHB are Prosaro-pro/ Caramba/ Miravis-Ace. These fungicides do not need to be tank-mixed with another product for spr aying. The fungicide products should be applied at the full rate recommended by the manufacturers. Strobilurin containing fungicides should not be sprayed at this stage.

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

In Illinois, wheat will start flowering within the next few days in much of the state. We are currently experiencing temperatures in the 90s after a long period of cool wet weather. Due to these temperature swings, it may be harder than usual to predict when flowering will begin. Wheat fields should be monitored every other day for flowering and a fungicide should be applied when most of the heads are at the early flowering stage or as soon as possible afterward.

--Jessica Rutkoski, Assistant Professor, University of Illinois at Urbana-Champaign

Depending on the location and the variety maturity, wheat in Kentucky is at Feekes growth stage 10.51 (early anthesis) or beyond. Most wheat fields in the most southern areas of Kentucky would likely have been at Feekes 10.51 last week or before. Many wheat fields that are closer to southern Indiana or southern Illinois would likely be at the Feekes 10.51 stage now or soon will be. For most of the state, FHB risk is low, but there are some areas that show medium to high risk. Many of these areas showing risk are those in which wheat likely was at Feekes 10.51 last week. The risk is likely due to weather that was received last week (rainy and cooler conditions). Within the next few days, the risk map model will likely account for the very hot and sunny days that currently are occurring, which will reduce the risk of FHB greatly.

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