There are some reports of winter wheat starting to show awns and we are likely only a few days away from heading and then flowering. The current scab risk in North Dakota is greatest for susceptible and very susceptible winter wheat varieties in southwest ND. I would expect scab risk to remain elevated for southwest ND in the coming days and we may see other pockets of scab risk appear with recent rain events. Please continue to use the risk model to assess scab risk as winter wheat starts to flower.

--Andrew Friskop, Assistant Professor and Cereal Extension Pathologist, North Dakota State University

In Wisconsin, wheat diseases have been nearly non-existent up to this point. Cool weather has generally kept wheat disease at low levels. However, increase frequency of rain events and moderate temperatures over the next 7-10 days will likely increase disease risk, especially Fusarium head blight (FHB or Scab).

We are entering the window for fungicide applications for FHB here in Wisconsin. Currently the Fusarium Head Blight Risk tool is predicting more areas of moderate to high risk in Wisconsin for FHB than it did a week ago. If highly susceptible wheat varieties were planted in Wisconsin, the current risk is high across most of the state. Rainy conditions in the next seven days will likely push this risk higher. Now is the time to consider a fungicide application to manage FHB in Winter wheat in the state.

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 due to the fact that 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.

For more information, please visit my June 1, 2022 update here: https://badgercropdoc.com/2022/06/01/wisconsin-winter-wheat-disease-upd….

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

Head Scab Risk has Increased Across Ohio.

Due largely to rainfall, high relative humidity, and warmer temperatures over the last several days, the risk for head scab is now moderate across most of the state of Ohio, and high across the south. The risk is low in NW Ohio. This would be the time to consider applying a fungicide to control head scab and reduce the risk of grain contamination with mycotoxins as fields reach anthesis in the northern third of the state. Even fields in the lower half of the state that flowered 5-7 days ago could benefit from a fungicide application. Most of the recommended fungicides for FHB management provide similar levels of FHB and vomitoxin suppression when applied between early anthesis (Feekes 10.5.1) and early grain-fill (up to six day after early anthesis).

The recommended, and most effective, fungicides for scab and vomitoxin control are Miravis Ace, Prosaro, Caramba, Proline, Sphaerex, and Prosaro Pro. These products provide comparable levels of scab and vomitoxin suppression when applied at early anthesis or shortly thereafter. Applications made to wheat at early or full head emergence (between Feekes 10.3 and 10.5) may also suppress scab (compared to no fungicide at all), but tend to be considerably less effective against vomitoxin. Several of these fungicides are also very effective against leaf diseases, which are also on the increase in some areas. Please read product labels carefully before making an application, in particular, pay close attention to the preharvest intervals.

--Pierce Anderson Paul, Extension Plant Pathologist, The Ohio State University

Most areas of Central and Southern PA have flowering wheat, or wheat that is about to flower. Scab infection risk is growing across the state for all resistance classes of wheat. If your wheat in these areas is heading and approaching flowering, stay alert and consider a fungicide application. 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. 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. Follow labels to determine post-harvest interval constraints for the fungicide you choose.

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

The next several days are a critical fungicide spray decision time for winter wheat in New York. The majority of fields will initiate flowering during the early to middle portion of next week. 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. Though the calculated risk of FHB infection has previously remained low, the risk level is expected to increase with widespr ead rain over the next few days. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu/) and your local weather forecast frequently as your winter wheat crop approaches flowering. Most winter barley in New York is past growth stages when fungicide application should be considered.

You are invited to attend the Cornell Small Grains Management Field Day at Poorman Farms in Seneca Falls on June 2. Visit cals.cornell.edu/2022-small-grains-management-field-day to view the agenda and pre-register (free)!

--Gary Bergstrom, Extension Plant Pathologist, Cornell University

Wheat is, or will soon be, flowering (Feekes growth stage 10.5.1) in parts of central and northern Ohio. Feekes 10.5.1 is the growth stage at which the crop is most susceptible to infection by the fungus that causes head scab and produces vomitoxin. However, most fields across the state are currently at low risk for head scab. This is likely because of the relatively low temperatures we have experienced over the last few days. The map indicates that the risk for head scab development is low (mostly yellow) in fields flowering today, May 26, and assessments based on 2-6 days of forecasted weather suggest that the risk will continue to be low in the western 2/3 of the state where most of the wheat is grown and moderate (specks of orange) in a few areas out east. Continue to look at the tool as more fields reach anthesis; the risk could change quickly as it warms up, particularly if the warmer weather is accompanied by high relative humidity and/or frequent rainfall.

--Pierce Anderson Paul, Extension Plant Pathologist, The Ohio State University

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