Symptoms of Phytophthora blight on eggplant include leaf spots that can be large, fruit rot, crown rot, and dieback of the growing tip. Plants with the last two symptoms often die.
This disease has been more commonly found in cucurbit crops (especially pumpkin and squashes) and peppers. Other susceptible crops are tomato and snap bean.
The following photographs were taken of a crop growing in a field with no recent history of production of susceptible crops (it was in sod production). The pathogen may have been brought to this field in soil on farm equipment from an infested home farm field, indicating the ease with which this pathogen can be moved. Affected plants were in the lowest and wettest part of the field.
Management practices for Phytophthora blight include avoiding introducing the pathogen into a field, avoiding favorable conditions (soil saturated with water), applying fungicides starting before disease onset (preventive schedule), and promptly destroying affected plants at the start of an outbreak to limit spread. Presidio, Revus, Forum, and phosphorous acid fungicides are labeled for use on eggplant in commercial production fields. Later are recommended used at low rate tank-mixed with the others.
Please Note: The specific directions on pesticide labels must be adhered to — they supersede these recommendations, if there is a conflict. Any reference to commercial products, trade or brand names is for information only; no endorsement is intended.