The following plant disease highlights from the UK Plant Disease Diagnostic Laboratories represent recent sample submissions from field crops, fruit and vegetables, and ornamentals.
During the past week, field crop diagnoses included summer black stem on alfalfa; brown stripe on orchardgrass; brown spot on soybean; soreshin, black shank, tobacco ringspot virus, tomato spotted wilt virus, Fusarium wilt, and potassium deficiency on tobacco.
On fruit and vegetable samples, diagnoses included Cercospora leaf spot on blackberry; black rot on grape; bitter rot on apple; brown rot on peach; anthracnose on bean; Cercospora leaf spot on rhubarb; scab on potato; early blight, Septoria leaf spot, leaf mold, and southern blight on tomato. Numerous cucurbit diseases were diagnosed, including anthracnose (cantaloupe), downy mildew (cucumber), Alternaria leaf blight (cucumber, watermelon), Cercospora leaf spot (cantaloupe, squash, watermelon), gummy stem blight (watermelon), and Fusarium basal stem rot (squash).
On ornamentals and turf, we diagnosed Volutella canker on boxwood; rosette and black spot on rose; Seiridium canker on Leyland cypress; anthracnose on oak; and brown patch on fescue.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians