Office of Research

Phytophthora Blight of Vegetables

Phytophthora blight

Eggplants and peppers are especially susceptible to Phytophthora blight.

Illinois produces approximately 36,000 acres of cucurbit crops (cucumbers, cantaloupes, gourds, pumpkins, squash, and watermelons) annually.  More than 90 percent of the processing pumpkins produced in the U.S. are grown and processed in Illinois, as well as more than 1,500 acres of eggplant and pepper. Phytophthora blight, caused by Phytophthora capsici, is the most serious threat to the production of cucurbit, eggplant, and pepper in Illinois, as well as nationwide.

Mohammad Babadoost initiated research to develop effective control for Phytophthora blight. After intensive research on determining resistant cultivars, establishing effective crop rotations, testing more than 50 fungicides with potential effects on Phytophthora, effective IPM strategies have been recommended for management of Phytophthora blight.

In peppers and eggplants, growers can manage Phytophthora blight by using resistant cultivars, practice 3-year crop rotations, and apply effective fungicides. In cucurbits, Phytophthora blight can be managed by practicing 3-year crop rotation, avoiding contaminated water with P. capsici, and application of effective fungicides. Now, there are seven fungicides effective against foliar blight and fruit rot of peppers and cucurbits caused by P. capsici in Illinois. All of these fungicides received registration for use on peppers and cucurbits, based on the data generated in Illinois and other few states.

Babadoost’s research has led to reduction in yield losses in cucurbit fields from up to 100 percent to less than 10 percent. As a result, acreage and yield of processing pumpkins doubled in the past 10 years.