Anthracnose
Caused by: Colletotrichum graminicolaProblem Category: Fungal Disease
Symptoms: Anthracnose symptoms vary widely depending on numerous factors such as genotype, age of plant and environmental conditions; small oval or elongated water-soaked spots which enlarge up to 15 mm long appear on leaves; lesions develop a tan center and red-brown or orange border; lesions may coalesce to form large necrotic patches; severely infected leaves on susceptible hybrids may wither and die; fungal fruiting bodies develop on dead tissues and may produce pink or orange spore masses; the fungus may also cause top dieback and stalk rot.
Comments: Fungus overwinters on crop debris; emergence of disease is favored by high temperatures and extended periods of wet and cloudy weather; seedlings and mature plants are most susceptible to the disease.
Management: Plant hybrids resistant to anthracnose; rotating crops and plowing crop debris into soil may help reduce incidence of early season infections.
Control: