Avoid overhead watering, watering late in the day or other practices that prolong periods of leaf wetting. Repeat in two to three months, if necessary. Chlorothalonil or mancozeb may be applied on a protectant basis for shoot infections. Apply at new leaf emergence and at 7 to 14 day intervals. On evergreen species, the leaves become chlorotic and roll downward parallel to midrib and eventually wilt.
Growth is stunted.
Fine roots decay, and cankers may develop at the base of the stem. Phytophthora-specific fungicides are available. Generally, their use is not recommended for established plantings. Remove and destroy affected plants. If practical, improve soil drainage and replant with a more tolerant variety.