Oklahoma's cool, rainy spring is making its mark on some of the state's wheat crop. Stripe rust infections in some Oklahoma wheat fields continue to activate, mostly triggered by recent rains, heavy dew and moderately cool weather conditions, Oklahoma State University experts said. “Texas had more stripe rust develop than leaf rust this year, and that’s what has moved northward in terms of foliar diseases,” said Bob Hunger, OSU Extension wheat pathologist. “There’s been some powdery mildew, some leaf spotters, but stripe rust has been the most widespread.” There have even been reports of stripe rust occurring in wheat heads in southwestern Oklahoma. As far as OSU experts have been able to determine, the grain is not infected; it is the plant tissue surrounding the grain.