FHB Alert Blog

FHB Update from WI, 05/28/17

We are quickly approaching head emergence and anthesis on many varieties in the state of Wisconsin. I predict that anthesis (flowering) will take place within the next week or so in Wisconsin. Farmers should focus on making a decision on fungicide application to control Fusarium head blight (FHB or scab). At this point, I think farmers should hold off on a fungicide application specifically for stripe rust. The major focus for fungicide application on winter wheat in Wisconsin should shift to managing FHB. With this said, the two primary products that have performed well in Wisconsin for FHB, also perform well on stripe rust and are ranked excellent in the Small Grains Fungicide Efficacy Table. This means that spraying for FHB will also control stripe rust, as long as the stripe rust epidemic has not advanced to high levels on the flag leaves. Currently, the Fusarium Head Blight Prediction Center is ranking much of the primary winter wheat growing area of Wisconsin at medium to high risk for FHB on susceptible varieties. Plenty or rain and adequate temperatures are making conditions ripe for FHB in the major wheat production area of the state.

The next 7-10 days poses a critical time to make a decision for fungicide application to control FHB and stripe rust. The primary fungicides for control of FHB are Caramba and Prosaro. I would urge you to wait until anthesis has begun in your field before applying. We have observed poor control of FHB where application of these effective fungicides was made before anthesis. In fact, we have observed improved control of FHB and lower levels of DON in finished grain where fungicide application was delayed 4-5 days after the beginning of anthesis, compared to applications at the start of anthesis. Also, remember that application of fungicides should be made no later than 6-7 days after the start of anthesis. After this time, fungicide efficacy on FHB is much reduced. Finally, DO NOT use any fungicide products that contain a strobilurin fungicide after the "boot" stage in wheat. Some studies have demonstrated that using strobilurin fungicides at, or after heading, can result in increased vomitoxin (DON) levels in finished grain. Get out there and SCOUT, SCOUT, SCOUT!

--Damon Smith, Extension Plant Pathologist, University of Wisconsin

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

FHB Update from NY, 05/26/17

Most winter malting barley fields in New York have headed out and the remainder will do so this week. Foliar sprays of Caramba or Prosaro up to seven days after head emergence may still result in significant FHB and DON suppression. Fungicide products containing strobilurins should not be applied to headed wheat or barley as they may result in increased levels of DON in grain. A heads emerged spray with these triazole fungicides also helps protect upper leaves against fungal leaf blotches, powdery mildew, and rust. Even though we have had frequent rains, the Fusarium Risk Assessment Map shows mostly low risk of Fusarium infection in New York because temperatures have been considered too low for spore production.

This is a critical week ahead for fungicide spray decisions on winter wheat. Winter wheat in New York varies from boot stage to the initiation of flowering. The triazole products Caramba and Prosaro are the most effective fungicides for suppression of FHB and DON contamination when applied at flowering (emergence of anthers on heads). A flowering application of triazole fungicide 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. We have observed low levels of powdery mildew and fungal leaf blotches. We confirmed the first
stripe rust of the season today on winter wheat in Yates Co.! Foci were fairly large with severe rust in the lower canopy spreading to upper leaves, suggesting a number of rust reproduction cycles in these fields and possible local overwintering of the rust. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB 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

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

FHB Update from MI, 05/26/17

As of May 26, wheat is flowering in southern MI and heads will soon emerge in the central region.. The prediction model for scab suggests the risk of scab on currently flowering wheat is relatively low, but growers are encouraged to visit this site repeatedly as the forecast can change rather quickly.

When contemplating the use of a fungicide for wheat In MI, growers are encouraged to consider the potential benefit of reducing the risk of scab infections as well as reducing loses to grain yield by leaf diseases. To date, the level of leaf diseases (powdery mildew, leaf spots and rusts) have been kept in check by weather conditions, but this is likely to change if high precipitation rates persist and temperatures become more moderate. Knowing one’s variety is key, especially with soft red varieties, as there are considerable differences in susceptibility to both leaf diseases and scab within popular varieties. Caramba and Prosaro remain the fungicides of choice for suppressing scab and leaf diseases. The window of application generally begins when most of the dominate stems have begun to flower (have exposed anthers). The window usually extends for about 5 to 7 days beyond this point depending on ambient temperatures.

Questions can be directed to Martin Chilvers (chilvers@msu.edu) or Martin Nagelkirk (nagelkir@msu.edu; 810-404-3400)

--Martin Nagelkirk, Extension Educator, Michigan 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

FHB Update from KS, 05/25/17

The wheat in southeast and south central Kansas is at the late milk and dough stages of kernel development. The symptoms of Fusarium head blight (head scab) are most evident at these growth stages and it is important for growers to be out looking for disease this week. Symptoms will soon be masked by natural maturity of the crop.

--Erick DeWolf, Extension Plant Pathologist, Kansas 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

FHB Update from US, 05/25/17

Welcome to the Fusarium head blight predictions center. The focus of the prediction effort is currently on the norther soft red winter wheat region where the wheat crop is at or approaching the flowering stages of growth that are most vulnerable to Fusarium head blight. The risk map is currently indicating low risk for most of this area but there are a few areas with moderate risk. Be sure to select state you are most interested in from the menu to the left of the risk map. This will also you to zoom in to see more details of the map and read commentary from local disease specialists.

--Erick DeWolf, Extension Plant Pathologist, Kansas 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

FHB Update from OH, 05/22/17

Wheat is now flowering in parts of northern Ohio and will continue to flower over the next weeks of so. According to the FHB forecasting system (http://www.wheatscab.psu.edu/), the risk for scab is low in central and northern Ohio for fields flowering at this time. Although it has rained over the last 2-4 days in parts of the flowering regions, conditions were relatively cool and dry last week, which likely reduced the risk of the scab fungus infecting the wheat spikes. Remember, the scab tool uses average relative humidity during the 15 days immediately before flowering to assess the risk of scab. If 11-13 days during that 15-day window are cool and dry, then the overall risk will likely be low, even if it is wet and humid on the other 2-4 days. Continue to keep your eyes on the weather and the forecasting system over the next week. Fields flowering at the end of this week or early next week (May 26-30) may still be at risk for scab. Prosaro and Caramba are the two fungicides recommended for head scab control. Stay away from the strobilurins when the risk for scab is high as they have been linked to higher grain contamination with vomitoxin.

--Pierce Paul, Extension Plant Pathologist, Ohio 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

FHB Update from SD, 05/22/17

Some of the winter wheat in SD is starting to head. This wheat growth stage is the best time to start monitoring the risk for Fusarium head blight (FHB). The most important risk factor for FHB is rainfall when wheat is at flowering. The current predicted risk for FHB for SD is mainly low for the most parts of the state. A moderate risk is predicted for portions of Miner, Lake and McCook counties as well as southwest counties. Keep monitoring the risk for scab until wheat is done flowering. For areas predicted to have a moderate or high risk of FHB, a triazole fungicide applied at flowering is recommended.

--Emmanuel Byamukama, Extension Plant Pathologist , South Dakota 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

FHB Update from NY, 05/19/17

Winter malting barley fields in New York range from in the boot to heads fully emerged. Development is further ahead in the Hudson Valley region. Conditions have been very conducive for local spore production by the Fusarium Head Blight (FHB) fungus. The Fusarium Risk Assessment Map has shown moderate to severe risk for large areas of the state this week and through this weekend. Application of an effective triazole fungicide product, specifically Caramba or Prosaro, is recommended as soon as all of the barley heads have emerged to suppress FHB and DON production as well as to protect upper leaves from foliar diseases. Sprays up to seven days after head emergence may still result in significant disease suppression. Fungicide products containing strobilurins should not be applied to headed wheat or barley as they may result in increased levels of DON in grain. Significant levels of scald disease have been observed in some barley fields. Low levels of powdery mildew and spot blotch have been observed, though no rusts have been seen to date. This is a critical time for triazole fungicide application to winter barley and I urge close observation of crop development and weather forecasts.

Winter wheat in New York is at stem elongation to flag leaf visible stages, so flowering is still about 10-14 days ahead. Some wheat is further ahead in the Hudson Valley. The triazole products Caramba and Prosaro are the most effective fungicides for suppression of FHB and DON contamination when applied at flowering (emergence of anthers on heads). A flowering application of triazole fungicide should be based on Fusarium head blight (FHB) risk as well as the risks of powdery mildew, rust, and fungal leaf blotches in the upper canopy based on scouting of individual fields. We have observed low levels of powdery mildew and fungal leaf blotches but no stripe rust or leaf rust to date. There is an application window of approximately 7 days from the beginning of flowering in which reasonable FHB 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

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

FHB Update from PA, 05/19/17

Our scab risk continues to be quite low in PA. Wheat flowering now is not very threatened by head scab. Rains early next week may drive our risk up, so continue to check the forecasting site regularly. Recent hot temperatures and sunny days have compressed the heading/flowering window for wheat, so your crop may be further along than you think. If you choose to spray your wheat, you can do so from the beginning of flowering up to about 5 days following the beginning of flowering. Remember, sprays applied PRIOR to flowering will NOT provide significant suppression of scab or toxin production. Caramba or Prosaro are effective on scab and give control of most leaf diseases and glume blotch. They do not need to be tank mixed with another product to control these diseases. If these products are unavailable, Proline and Folicur (which together provide the same chemicals as Prosaro) may be tank mixed at a rate of 3 + 3 fl oz/A. 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. Do NOT use any strobilurin-containing fungicides at heading or beyond.

--Alyssa Collins, Extension Field Crops Pathologist, Penn 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

FHB Update from MD, 05/19/17

Wheat is Maryland is now in the grain filling stage. With the showers that we had at flowering, there are high chances of substantial Fusarium Head Blight incidences. Consequently, tombstones (shriveled scabby kernels) and DON content are going to be a concern for the growers. To assess the incidence of FHB, you may randomly pick 20-25 heads of wheat per 1-2 acres and count the spikes having bleached spikelets. Harvesting from fields with high levels of FHB incidence should be done with higher fan speeds to remove lighter tombstone kernels. The farmers are advised to get the DON content analyzed in the grain before taking it to the market.

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

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

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