Grape black rot, Guignardia bidwellii, is a fungus and fungal disease, which attacks grape vines especially during hot and humid weather conditions. The name comes from the black fringe that borders growing brown patches on the leaves. The disease also attacks other parts of the plant.
Black rot is the most serious disease of crucifer crops world wide when environmental conditions are favorable. The disease affects primarily aboveground parts of plants at any stage of growth and causes high yield and quality losses, especially in tropical and subtropical regions during the rainy season. All vegetables in the crucifer family, including broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, kale, mustard, radish, rutabaga, and turnip, are susceptible to black rot.