FHB Update from KY, 05/29/14

The vast majority of wheat in KY is now passed the most susceptible period for FHB (i.e., flowering, more technically called anthesis). In the far west, symptom expression is almost complete. In many other fields, symptom expression is still developing. Based on what I have seen so far, it looks like most fields have escaped serious damage, but some fields do have moderate incidence of the disease. DON contamination in grain should not be a widespread problem, but it will be an issue in some fields as we approach maturity.

Generally, levels of other diseases are low. Exceptions are that some fields and portions of fields have extensive development of speckled leaf blotch. This is especially true where fungicides were not sprayed. Speckled leaf blotch is a cool season disease and has apparently been favored by the cooler than normal season we are experiencing (overall) thus far. Fortunately, this disease is not very aggressive in terms of yield damage unless it is quite extensive on the flag leaf. Unlike nodorum blotch, which is at currently at very low levels in the state, speckled leaf blotch will NOT move up to the head and cause damage.

Leaf rut can be found in many fields at this time, but incidence and severity are spotty, certainly too little, too late to cause significant yield loss in fields that were not treated with a fungicide. Fields that were treated with a fungicide should be good to go. I have not seen either stripe or stem rust so far this season.

--Don Hershman, Extension Plant Pathologist, University of Kentucky

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 http://www.scabusa.org