Vegetable Diseases Updates:

Pepper Southern Blight. Southern blight of pepper caused by the fungus Sclerotium rolfsii, was observed in one bell pepper field in central Illinois. This fungus is a soilborne pathogen and has a broad host range. For more information on southern blight, click here.

Pumpkin Powdery Mildew. Powdery mildew of pumpkin, caused by the fungus Sphaerotheca fuliginea, was observed on July 31st and August 1st, in several pumpkin fields in central Illinois. Powdery mildew occurs in cucurbit fields in Illinois every year. If powdery Mildew develops in July or early August, at the time of fruit set, it can cause substantial yield losses. Application of fungicides is needed to prevent heavy yield losses. Several fungicides such as Quadris, Nova, Flint, and Topsin-M can effectively control powdery mildew of pumpkins and other cucurbits. Since other diseases of pumpkins such as downy mildew, Plectosporium blight, and bacterial spots commonly occur in Illinois, application of a mildewcide mixed with a copper compound is preferred. For more information on powdery mildew of cucurbits, click here.

Pumpkin Cercospora Leafspot. Cercospora leafspot of pumpkin, caused by the fungus Cercospora citrullina, was observed in pumpkin fields in central Illinois. Small, gray lesions, 3-8 mm in diameter, developed on leaves. Centers of some lesions grew thin and dropped out. This disease can be controlled by applications of fungicides. For more information on Cercospora leaf spot, click here.