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.
Diseases diagnosed on agronomic crops during the past week have included brown spot on soybean; black shank (Figure 1), soreshin, Fusarium wilt, and frogeye leaf spot on tobacco.
On fruit and vegetable samples, we have diagnosed black rot on grape; frogeye leaf spot and cedar-apple rust on apple; brown rot on nectarine; Pythium blight and root/stem rot, southern blight, and ashy stem blight on bean; Cercospora leaf spot on melon; bacterial spot, Fusarium crown rot, and Rhizoctonia stem rot on pepper; anthracnose and squash vine borer on pumpkin; bacterial spot, early blight, Septoria leaf spot, leaf mold, Pythium and Rhizoctonia root/stem rots, southern blight, and tomato spotted wilt virus on tomato.
Ornamental and turf samples included downy mildew on rudbeckia; scab on crabapple; anthracnose and powdery mildew on oak; Nectria canker and potato leaf hopper injury on maple; Cytospora canker and Cercospora leaf spot on willow; and Pythium root dysfunction and take-all on bentgrass.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians