The following plant disease highlights from the University of Kentucky Plant Disease Diagnostic Laboratories represent recent sample submissions from field crops, fruit, vegetables, and ornamentals.
Recent agronomic samples have included summer black stem on alfalfa; gray leaf spot, northern leaf blight, common rust, and Stewart’s wilt on corn; downy mildew and frogeye on soybean; black shank, frogeye leaf spot, and frenching on tobacco.
On fruit and vegetable crops, we have seen bitter rot and black rot on grape; bitter rot on apple; anthracnose on cucumber; bacterial spot on pepper; downy mildew, powdery mildew, Plectosporium blight, and angular leaf spot on pumpkin; Septoria leaf spot, and early blight on tomato.
On ornamentals, we have diagnosed Cercospora leaf spot, Rhizoctonia and Pythium root rots, and Fusarium wilt on chrysanthemum; Volutella canker on boxwood; tar spot and Phyllosticta leaf spot on maple; bacterial leaf scorch on oak; and Verticillium wilt on maple and tuliptree.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians