Winter wheat in South Dakota has started flowering, which is also a period when Fusarium head blight (FHB) starts to develop. FHB can cause significant grain yield loss through reduced grain weight and poor quality due to accumulation of mycotoxins mainly deoxynivalenol (DON). The only in-season FHB management practice is by applying a fungicide when the risk for FHB is moderate to high. The timing of the fungicide is crucial in order to maximize protection against FHB. The fungicide needs to be applied at the flowering time, if the risk for FHB is moderate or high. Currently the FHB prediction tool is showing low to high for risk depending on the FHB resistance in the variety planted. Some areas in the state are relatively dry hence the low FHB risk in these areas. However, the FHB risk is likely to change as weather changes. It is advisable to keep checking the predicted FHB risk until wheat has completed the flowering (about 6 days prior to flowering and 6 days after flowering) to be out of danger for FHB. Best fungicides to apply to manage FHB include Prosaro, Miravis Ace, Caramaba.

--Emmanuel Byamukama, Assistant Professor and Plant Pathology Extension Specialist, South Dakota State University

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, NE, MI, NY, and WI. Wheat in parts of these states likely at or 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 east of the Mississippi river. However, recent rainy and humid weather in the Great Plains has increased the risk of disease in areas of KS, NE and parts of WI. Growers in these areas should check the growth stage of their crop and consult local advisors for additional information about the risk of disease in their area.

--Erick DeWolf, Plant Pathologist, Kansas State University

Much of the winter wheat in New York will begin flowering (emergence of yellow anthers on heads) over the 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 FHB and DON contamination when applied at flowering. 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. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB and DON suppression can be expected. Severe powdery mildew has been observed in some mildew-susceptible varieties. Risk of FHB infection has remained low primarily because of low temperatures which could change over the next several days. 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.

Winter malting barley is generally beyond growth stages at which a foliar fungicide application should be considered

Be sure to join us for Cornell’s Virtual Small Grains Management Field Day on June 3 at 10 AM EDT (https://blogs.cornell.edu/ccefieldcropnews/2021/05/19/2021-small-grains…).

--Gary Bergstrom, Extension Plant Pathologist, Cornell University

Pockets of higher scab infection risk exist in Western and Northern PA as we wrap up May. Those growers who are working with highly susceptible varieties that are about to flower should consider a fungicide application on those crops. Generally, recent dry weather has driven down risk levels for most varieties across the state, but central and Northern growers should keep an eye on their risk map as rain-generating weather fronts become more frequent.

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

Predicted Risk for Head Scab Continues to be Low Across Ohio. Although it has rained over the last few days, temperatures have dropped into the upper 50s and lower 60s, with nighttime temperatures in the mid-to-upper 40s in some places. Cold temperatures between anthesis and early grain fill usually reduce the risk for scab, as the disease develops best under warm, wet, or humid conditions. However, do keep your eyes on the weather and the forecasting system as the crop continues to go through the anthesis growth stage over the next few days, particularly in the northern third of the state. The forecast is for warmer temperatures and isolated showers over the Memorial Day weekend and into next week (the week of May 31). Late-developing fields may still be at risk for head scab as temperatures increase, particularly if it stays wet and humid. You may need to consider applying Prosaro, Caramba, or Miravis Ace, but remember, these fungicides are most effective against head scab when th ey are applied at or a few days after anthesis.

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

Wheat is at the dough stage in the lower eastern and lower western shore of the state. Wheat is well past the stage of FHB infection and spray here. This year, we were lucky to not be at high FHB risk in this part of the state. Some other fungal foliar diseases such as Septoria tritici blotch, Stagonospora nodorum blotch, glume blotch, and tan spot have been observed. However, the damage due to these diseases is not going to be substantial now, and growers in this region do not need to spray fungicides for controlling these diseases. This week and next would be the time to start looking for bleached spikelets to assess FHB severity. Up in the North, wheat has finished/ is finishing up flowering. FHB risk for today and for the next three days appears to be low here, especially for a moderately resistant variety. If you are worried about foliar diseases mentioned above, the triazole fungicides do an excellent job of controlling these diseases as well. Strobilurin containing fungicides should be avoided at this stage.

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

Wheat in much of north central and northwestern portions of Kansas is now at the heading and flowering stages of growth. These growth stages are vulnerable for infection by Fusarium head blight. Wheat in many areas of central, south central and southeastern regions of the state are mostly past flowering and into the early stages of grain development. Although there is still some risk of infection during grain development, the risk of severe disease is lower than when wheat is flowering.

The risk of severe head blight is moderate to high in most areas of Kansas. This estimate of disease risk assumes that wheat varieties are susceptible to head blight. Adjusting the assessment to estimate the risk of severe disease for moderately susceptible or moderately resistant varieties, such as Everest, WB4469, Zenda, greatly reduces the risk of severe disease. To view these risk maps, select the menu button from the upper left corner of the webpage. Then select the desired resistance level from the menu. Growers with fields that are still flowering in high risk areas should apply fungicides to help suppress the risk of severe Fusarium head blight. Growers should use fungicides such as Prosaro, Caramba or Miravis Ace that are known to suppress head blight. Other fungicides provide little or no protection from head blight.

--Erick DeWolf, Plant Pathologist, Kansas State University

Wheat in the Eastern Shore of Maryland and Southern Maryland on the west of shore is finishing up flowering. If your wheat has flowered already, you have likely escaped FHB risk successfully this year. Wheat in the Northern parts (Frederick, Carroll and Harford counties) is either flowering/ will soon start flowering. The FHB risk the state is predicted to be low currently and in the next couple of days to come. If your wheat is yet to flower within this week or the next, keep an eye on the FHB forecasts. I will post updated risk commentaries, if things change over the next week.

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

Much of the winter malting barley in New York reached full head emergence in the past several days when the Fusarium Risk Assessment Map (www.wheatscab.psu.edu) indicated low risk of Fusarium head blight (FHB) across the state. 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. We are currently observing low levels of scald and powdery mildew in winter barley.

Much of the winter wheat in New York is at boot stage and is expected to initiate flowering during the first week in June. 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. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB and DON suppression can be expected. Severe powdery mildew has been observed in some mildew-susceptible varieties. Check the Fusarium Risk Assessment Tool (www.wheatscab.psu.edu) and your local weather forecast frequently as your winter wheat crop approache s heading and flowering.

--Gary Bergstrom, Extension Plant Pathologist, Cornell University

Wheat in much of central Kansas is now at the heading and flowering stages of growth that are most vulnerable for infection by Fusarium head blight. The risk is currently low for most areas of the state. The risk of severe head blight will likely increase over the next 48-72 hours as the region experiences more rainy and humid weather. You can see estimates of disease risk based on forecasted weather conditions by selecting the “48” or “72” buttons from the menu above. Growers may want to apply a fungicide to help suppress the risk of severe Fusarium head blight along with foliar diseases that are also active in the region such as stripe rust. Growers should use fungicides such as Prosaro, Caramba or Miravis Ace that are known to suppress head blight. Other fungicides provide little or no protection from head blight.

--Erick DeWolf, Plant Pathologist, Kansas State University