Wet Weather May Spell Disease Troubles for Wheat

WOOSTER, Ohio — Ohio’s wheat is performing well despite recent rains, but saturated soils may have created favorable conditions for disease development. Pat Lipps, an Ohio State University plant pathologist with the Ohio Agricultural Research and Development Center, said that diseases like powdery mildew, Stagonospora leaf blotch and Fusarium head scab may become a problem if moist conditions continue. “The wheat looks like it’s in really good condition and I don’t think that the recent wet weather has caused any major problems with growth and development,” said Lipps, a professor with OARDC’s Department of Plant Pathology. “But there are some side effects from the wet conditions that we are concerned about.” One concern is the development of head scab or Fusarium head scab, a fungal disease that can have a devastating impact on wheat production and yields if it develops during the crop’s flowering stage. Wheat throughout southern Ohio is beginning to flower and the crop in the northern part of the state will be flowering by Memorial Day weekend. “Ohio is extremely wet right now which is favorable for Fusarium fungus to grow, which is setting the scenario for lots of spores when the wheat goes into flowering,” said Lipps. “We are going to be very diligent in watching the weather because flowering is very critical for Fusarium head scab infection.” According to OARDC’s head scab prediction model, areas in southern Ohio, particularly around Jackson and Miami counties, are already reporting a high to moderately high risk of head scab development in wheat fields. Another disease that may develop due to wet, cool conditions is Stagonospora leaf and glume blotch, a disease that can cause infections if spores are splashed onto the plant. “Stagonospora lives on old residues on the lower leaves of plants. Because of the rain, spores could have splashed onto the upper leaves of the wheat crop and may cause leaf infections,” said Lipps. “Growers should be scouting their fields right now for the development of lesions, a sign that the disease is present.” Powdery mildew is currently showing up on susceptible wheat varieties, said Lipps. “Anybody growing susceptible varieties needs to pay attention to that and apply fungicides if the upper leaves are showing disease. They should be scouting their fields at heading or before heading occurs.” According to the Ohio Agricultural Statistics Service, 3 percent of Ohio’s wheat is heading. “Fields are drying off fairly quickly, but if the rains continue, it will be setting the stage for some major disease problems,” said Lipps.