Management: Confirm your field diagnosis by sending in a sample to MSU Diagnostic Services for positive identification of the fungus. Avoid overhead watering or wetting the foliage of susceptible plants. Plants weakened by drought stress or planted in wet soils are more susceptible to infection by Phytophthora spp. Fungicides are not effective if plants have already been infected; remove and destroy infected plants. Susceptible plants growing in close proximity to infected ones should be treated promptly with a preventative fungicide.