Cucurbit downy mildew reported in North Carolina | North Carolina Cooperative Extension

Source: Cucurbit downy mildew reported in North Carolina | North Carolina Cooperative Extension

Downy mildew of cucurbits, a critical disease on cucumbers, has been reported in North Carolina. It was observed on cucumber in Sampson county. The field had 5% disease incidence, with the infected plant/leaf having 5% disease severity.

Cucurbit downy mildew is a foliar disease caused by a fungal-like organism called Pseudoperonospora cubensis. This disease attacks all commercial cucurbits (cucumber, cantaloupe, squash, watermelon, pumpkin, etc.), but is most severe on cucumbers. The chlorotic lesions and greyish-purple “downy” growth on the underside of infected leaves are all-too familiar to anyone who has planted cucurbits in the last ten years. In 2005 the pathogen overcame resistance in host plants and became seriously damaging to cucumber crops in many states. Although many research groups and companies are working on developing resistant lines and effective chemical control, downy mildew continues to be problematic for cucurbit growers annually.