Gardeners warned about downy mildew

PARKERSBURG -Area gardeners are being warned to watch out for downy mildew in cucumbers.

Because of wet conditions this summer, downy mildew and other fungal disease may affect Mid-Ohio Valley gardeners more than usual, said J.J. Barrett, WVU Extension Agent for Agriculture in Wood County.

Downy mildew is a disease that attacks cucumbers and other members of the cucurbit family.

Cucurbits are members of the gourd family Cucurbitaceae include garden crops like cantaloupe, cucumber, pumpkin, squash and watermelon.

Downy mildew is prevalent in areas with high humidity and rainfall.

”The disease, caused by the pathogen Pseudoperonospora cubensis, is usually an annual, late-season problem on squash and pumpkin in the eastern and central U.S. but has become one of the most important diseases in cucumber production,” Barrett said. ”Downy mildew can spread from field to field on air currents via tiny, microscopic spores.

”Cool, wet, and cloudy conditions (60 to 80 degrees Fahrenheit) help to create an ideal environment for downy mildew.

Favorable conditions can result in plants becoming completely blighted within 14 days from the time the downy mildew spores land on plant leaves.”

Downy mildew attacks plant leaves.

Symptoms of the disease cause angular, chlorotic lesions on the foliage. These lesions appear angular because they are bound by leaf veins.

During humid conditions, inspection of the underside of the leaf reveals gray-brown to purplish-black “down.” This is the sporulation of the pathogen.

Downy mildew causes yellow lesions that may be visible on the top surface of infected leaves.

For more information call the WVU Extension Office in Wood County at 304-424-1960.