Mulches can suppress weeds. Heavy rains can splash soil onto lower leaves and bring them into contact with soil-borne diseases. Mulches can reduce this soil splash. Select disease and insect resistant varieties of plants which are adapted to local growing conditions. Rotate crops, when possible.
Crop rotation can reduce the buildup of soil-borne diseases.
Practice proper sanitation . Remove crop residues, diseased plant materials, trash and weeds from the garden plot. Clean up crop residue as soon as harvesting is completed. Remove infected leaves immediately. Dispose of severely diseased plants before they contaminate others.