It is also important to destroy any plant residues after harvest. Powdery mildew is a fungus disease that first appears on the upper leaf surfaces of the plant. Under favorable conditions, the white, powdery spots will spread over the entire leaf. Infected spots will eventually turn brown and dry. It is most prevalent in late summer and early fall when warm weather, afternoon showers and dense foliage create an ideal environment for the disease to develop.
Chemical control involves application of registered fungicides at the first sign of infection.
Fields under sprinkler irrigation should be watered in the early morning to give foliage a chance to dry before evening. Bacterial wilt is spread by both the striped and spotted cucumber beetles that feed on young seedling pumpkins. The first symptoms are dull green patches that appear on leaves that show feeding wound damage. Individual leaves eventually wilt, followed by vines, then the entire plant. Symptoms can also include extensive blossoming and branching on dwarfed plants.