Symptoms: Affecting a wide variety of plants, including roses, beans, tomatoes and peppers, mosaic is a viral disease found in many gardens throughout the United States. The disease may be difficult to detect as symptoms look similar to several nutrient deficiencies. Look for yellow or green stripes or spots on foliage. Leaves may be wrinkled or curled, growth may be stunted and yields are greatly reduced. Infected fruit appears mottled and develops raised “warty” areas. It is often mishappen.
Mosaic virus overwinters on perennial weeds and is spread by insects that feed on them. Aphids, leafhoppers, whiteflies and cucumber beetles are common carriers of this disease. Cuttings or divisions from infested plants will also carry the virus.
Control: There are no cures for viral diseases such as mosaic once a plant is infected. As a result, every effort should be made to prevent the disease from entering your garden. Choose resistant cultivars when available and spot treat with natural pest controls, such as insecticidal soap, and diatomaceous earth, to reduce the number of disease carrying insects. Floating row covers will keep pests off vulnerable crops and should be used until bloom. Remove all perennial weeds, using least-toxic herbicides, within at least 100 yards of your garden area. Avoid working in the garden during damp conditions (viruses are easily spread when plants are wet). Remove and destroy all infected plants.
Photo Credit: Michigan State University