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 gray leaf spot, Diplodia leaf streak, and southern corn rust on corn; rough leaf spot (Ascochyta) and sooty stripe on sorghum; Rhizoctonia web blight and summer black stem on alfalfa; compaction problems on soybean; angular leaf spot, black shank, frogeye leaf spot, target spot, and low pH symptoms on tobacco.
On fruit and vegetable samples, we have diagnosed black rot on grape; scab on peach; bitter rot and sooty blotch/flyspeck on apple; scab on pecan; Cercospora leaf spot on cucumber; bacterial spot and southern blight on pepper; scab on potato; angular leaf spot, Cercospora leaf spot, powdery mildew, and downy mildew on squash; Cercospora leaf spot, root knot nematode, squash vine borer, Pythium cottony leak, and spider mite injury on pumpkin; bacterial spot, early blight, Septoria leaf spot, leaf mold, Fusarium wilt, and spider mite infestation on tomato.
Ornamental and turf samples included Pythium root rot and Cercospora leaf spot on phlox; Rhizoctonia root rot on snapdragon; Fusarium wilt and Pythium root rot on chrysanthemum; anthracnose on oak; Rhizosphaera needlecast on spruce; and brown patch on fescue.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians