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 brown stripe on orchardgrass; black shank, Fusarium wilt, tomato spotted wilt virus, angular leaf spot, frogeye leaf spot, ozone injury (“weather fleck”), and manganese toxicity on tobacco.
On fruit and vegetable crops, we have seen common leaf spot on strawberry; black rot on grape; leaf spot (Coccomyces) on cherry; brown rot on peach; Cercospora leaf spot and Pythium root rot on bean; Cercospora leaf spot on cucumber; bacterial spot on pepper; vine borer, black root rot, and pollination problems on summer squash; early blight, Septoria leaf spot, Rhizoctonia and Pythium root rots, Fusarium wilt, and tomato spotted wilt virus on tomato.
On ornamentals and turf, we have diagnosed Pythium root rot on aster, chrysanthemum, and marigold; rust on hollyhock; powdery mildew on peony; Volutella blight on pachysandra; bacterial leaf spot on zinnia; anthracnose on elm and oak; tar spot on maple; leaf blister on oak; leaf blotch (Guignardia) on buckeye; Pythium root rot on bentgrass; and brown patch on fescue.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians