Brown Spots (Anthracnose) on Vine Crops
It starts with small yellowish or water soaked spots on the leaves that quickly enlarge and turn brown. This may be your first clue that the fungal disease, anthracnose, has moved into your melon, cucumber and gourd plantings.
This disease also attacks the stems and fruit. Severe stem lesions can girdle, preventing water from moving between the roots, leaves and vines. Although fruit lesions usually damage just the rind, not the edible portion, they do create an entryway for other insects and diseases.
Prevent anthracnose by growing resistant cultivars whenever possible. Do a thorough clean up at the end of the season and rotate plantings if space allows.
During the growing season water early in the morning so the plants dry completely before dark. If infection does occur you may decide to use a fungicide, according to label directions, to protect healthy plants from becoming infected.
A bit more information: This disease may survive in the soil for up to two years. Moisture spreads the disease and warm rainy weather increases the risk of infection. The disease may become epidemic when temperatures are between 70 and 80 degrees.