Devastating disease found in pumpkin fields

Pumpkin seedling death is caused by Phytophthora blight, the most devastating pumpkin disease in Illinois. (Photo by Mohammad Babadoost, University 0f Illinois)

A potentially devastating disease surfaced early in Tazewell County pumpkin research fields, causing a University of Illinois specialist to warn pumpkin and vegetable growers to scout for phytophthora capsici.

“This disease is devastating,” Mohammad Babadoost, a vegetable and fruit crop disease specialist, told FarmWeek. If left untreated “within 10 days, the pumpkin fruit will melt down.”

Babadoost attributed recent heavy, repeated rains and standing water for creating conditions, starting in low-lying areas, for spores to infect vines and fruits. The disease also was found in bell pepper plants in the Champaign area. Cucurbit species are susceptible including melons, cucumbers, zucchini and squash.

When growers first spot the disease, the specialist recommended fungicide treatment with Revus plus Kocide-3000 alternated with Ranman plus Silwet-77 at seven-day intervals. While the fungicide isn’t 100% effective, Babadoost described it as the best and reasonable cost-effective treatment in Illinois.

The severity of the disease hinges on the rainfall. If growers get light rains and dry periods, the losses could be minimal, according to Babadoost. “If we get more heavy rainfall, the infection will go on and on,” he added.

The impact could be felt not only in Illinois, but the rest of the country as well.

Babadoost noted Illinois grows three times more pumpkins than any other state and produces 90% of U.S. canned pumpkins, which are particularly susceptible to phytophthora capsici. In the late 1990s and early 2000, an Illinois outbreak resulted in 100% loss of pumpkins grown for canning.

“The canning industry panicked. We worked to minimize the losses,” the specialist said. Since 1999, Babadoost has continued to monitor pumpkin crop conditions at research trials in Tazewell County.