Smuts

Smuts generally produce dusty, irregular, sooty black spore masses on leaves, stems, flowers, and seeds.  They are common on corn, onions, and certain grasses.  Plants may be stunted, with withering of affected parts.

To control, cut and destroy infected plants.  Do not use diseased material in compost.  On onions, start with disease-free transplants, and rotate from areas where disease has occurred.  Use resistant sweet corn hybrids and maintain plant vigor.