Wheat in the Northern part of the state has started to flower this week, whereas wheat in the central part of the state has just finished flowering. Warm, wet weather will continue to elevate FHB risk in flowering wheat, and a fungicide application of Caramba, Prosaro, Proline, or Miravis Ace are suggested at this time. Applications are most efficacious when made following label directions between the start of flowering and 5 days after this point in time. Flowering is defined as the point in time when 50% of main tillers have started to push anthers. Do not apply products containing strobilurins for FHB management.
Wheat in the southern part of the state should now be showing symptoms and signs of FHB if severe infection occurred (bleached heads/portions or heads/spikelets with salmon colored growth). Recent surveys indicate that overall FHB levels are likely low in this part of the state. The central part of Illinois however, was under high risk across wheat resistance levels during the critical flowering period and should be monitored closely over the coming days. Symptoms of FHB will be most observable 18-24 days after flowering. If severe FHB is detected, you should be prepared to take measures to remove contaminated grain. These include increasing combine fan speeds and openings to blow out lightweight, FHB-infested grain, harvesting infected fields as early as possible (and preferably first) and if possible, storing grain from infested fields separately from quality grain. Ensure that grain is dried (15% optimal) to minimize continued growth of pathogen and DON accumulation in storage.
-- Nathan Kleczewski Ph.D., University of Illinois, Research Assistant Professor and Extension Specialist
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