Diseases of Vine Crops

Anthracnose

• The Colletotrichum lagenarium fungus causes anthracnose, which is a highly destructive disease that affects cucumbers, muskmelons, gourds and watermelons. Symptoms include the appearance of small, yellowish lesions on foliage and circular lesions on stems. Fruit infection occurs only is mature fruit. The lesions expand quickly and turn brown, killing large areas of the plant, especially the leaves. Planting resistant varieties, using certified seed and rotating fields are some of the ways to control anthracnose.

Fusarium Wilt

• Soil-borne fungi that are capable of surviving in the soil for long periods may cause Fusarium wilt in vine crops. The symptoms include wilting of older plants and leaves turning yellow. Sometimes vines affected by Fusarium present a pinkish-white fungal growth in wet weather. Methods of control include planting wilt-resistant species when possible, crop rotation of three to four years and soil fumigation in commercial production of vine crops.

Mosaic Diseases

• Mosaic viruses may cause dwarfing, mottling and distortion of leaves in vine crops. There are specific mosaic viruses for each type of vine crop. In some cases, insects carry the virus, as in the case of cucumber beetles and leaf hoppers. Gardeners working in wet weather can also spread the viruses. Control methods include planting disease resistant varieties and controlling insects.

Phytophthora Blight

• This fungal disease may cause complete destruction of zucchini, watermelon, pumpkin and summer squash fields. It can also cause damage in cucumber, tomato, peeper, eggplant and muskmelon crops. The main symptom of the disease is the rotting of the root and crown of the plants, which spreads rapidly, causing the death of the entire plant. Once plants have been infected, there is no cure and there are no varieties of vine crops resistant to Phytophthora blight. Rotating crops for a minimum of three years is a method that reduces the likelihood of infection.