Be Alert to Pre-harvest Intervals for Wheat Fungicides
May 22, 2009 While wheat disease appears to be relatively low so far this year (see Wheat Disease Updates in CropWatch), if you do need to apply fungicide, be sure to check the pre-harvest intervals on product labels, said Stephen Wegulo, extension plant pathologist.
Determined by the Environmental Protection Agency, these intervals are set to keep dangerous chemical residues from entering the food chain. For example, if you want to apply a fungicide with a pre-harvest interval of 30 days, be sure you have at least 30 days before you harvest. Even though the fungicide would break down some after harvest, the chemicals could carry over into food products made from treated grain.
Most economically important plant diseases are caused by fungi, Wegulo said. Bacterial diseases like Goss's wilt in corn and black chaff in wheat are typically controlled by resistance rather than bactericide because bactericides are not cost effective.
For more information on fungicides for wheat, see the table of registered wheat fungicides in the May 1 CropWatch.
Faith Colburn, Communication Specialist
West Central REC, North Platte