The following plant disease highlights from the UK Plant Disease Diagnostic Laboratories represent recent sample submissions from field crops, fruit, vegetables, and ornamentals.
During the past week, field crop diagnoses included gray leaf spot and northern leaf blight on corn; brown stripe on orchardgrass; soreshin, target spot, tobacco ringspot virus, alfalfa mosaic virus, and weather fleck on tobacco.
On fruit and vegetable samples, diagnoses included black rot on grape; brown rot on plum; bacterial spot and blossom end rot on pepper; Septoria leaf spot, tomato spotted wilt virus, Fusarium wilt, and root knot nematode on tomato; powdery mildew, Fusarium crown/root rot, Alternaria leaf blight, and Cercospora leaf spot on pumpkin; and Rhizcotonia stem rot on watermelon.
On ornamentals and turf, we diagnosed Rhizoctonia stem rot on bidens and vinca; web blight and bacterial blight on chrysanthemum; anthracnose and bacterial spot on ivy; anthracnose on ash and oak; Coccomyces leaf spot on cherry; Thyronectria canker on honeylocust; Seiridium canker on Leyland cypress; Botryosphaeria canker on maple and photinia; Cytospora canker on willow; Pythium root dysfunction on bentgrass; and summer patch on bluegrass.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians