powdery mildiew on cereal

agricultural agriculture agronomic agronomical agronomy ascospore attacked bacteria blight blumeria caused cereal chlorosis curl disease diseased erysiphe food fruit fungi fungicide fusarium graminicola graminis green greenhouse head leaf lose lost mildiew mycology natural nature necrose necrosis pathogen pathology pesticide phytopathology phytopharmacy plant protection pycnids spores spot treatment tritici wheat