Regular applications of maneb may also help slow the spread and development of Phytophthora blight on peppers. Some resistant pepper varieties are available for commercial growers. The disease has been especially severe on pumpkins and squashes in the past few years in various parts of Illinois. The occurrence of the disease on these crops is often associated with above average rainfall or excessive irrigation. On summer squashes the pathogen can attack the vines and fruit.
Infected vines become dark green, water soaked, and soft, eventually collapsing.
With pumpkin the symptoms on the vines are less severe than those which develop on the fruit. Infected fruit can develop a very strong odor, perhaps resulting from secondary infection by soft rot bacteria. Strategies for controlling Phytopthora blight on cucurbits include avoiding sites with a history of the disease, avoiding poorly drained sites and excessive irrigation, following crop rotation schedules that do not include other cucurbit or solanaceous crops, planting pathogen free seed, and the regular application of a protectant fungicide. Ridomil and Ridomil Gold are registered for use on cucurbits, but for the control of damping off and cottony leak cause by species of Pythium . However, these materials have not been shown to be effective for controlling Phytopthora blight on cucurbit crops.