This program will control most diseases of pumpkin, but it is still necessary to scout for development of powdery mildew and downy mildew. These fungicides should be applied at regular intervals depending on the susceptibility of the pumpkin variety. Our preliminary data indicate that maximum yield on susceptible varieties can be achieved only with weekly sprays. In some years it is not present at all because it requires high rainfall. Symptoms of downy mildew on pumpkin begin as angular yellow or chlorotic areas on the upper surface of leaves.
Sporulation occurs on the underside of leaves and appears as brown to gray.
The sporangia can be seen with a 10X hand lens and appear as barely distinguishable black or purple spots. Scout your field for the presence of downy mildew and apply Aliette or Ridomil Gold if it occurs. Remember that cucurbits are no longer on the Bayleton label, so unless you have material with the old label, it cannot be used. Below are the EFI values from weather stations located on the Eastern Shore June 16-23. Add 2 points for every overhead irrigation.