Alternaria leaf blight
Honeydew Alternaria Leaf Blight Alternaria cucumerina.jpg
Alternaria leaf blight (Alternaria cucumerina) on a honeydew melon leaf
Scientific Classification
Kingdom: Fungi
Phylum: Ascomycota
Class: Dothideomycetes
Order: Pleosporales
Genus: Alternaria
Species: Alternaria cucumerina
Alternaria leaf spot

Alternaria brassicae var. nigrescens Peglion

Macrosporium cucumerinum Ellis & Everh. (1895)

Alternaria leaf blight (Alternaria cucumerina) is a fungal pathogen of Cucurbits. The pathogens can persist in the soil for many years. The disease can move from field to field in soil on farm machinery, infected crop debris, and irrigation water. High soil temperatures favor disease development.[1]


Plants may be affected at any stage of growth. Young seedlings are killed or severely stunted. Older plants begin to wilt at midday for a few days, then permanently wilt and die. Vascular bundles are discolored becoming yellow or brown.[1]


Use resistant varieties when available. Avoid known infested fields for production of a susceptible crop. Wash equipment when moving from one field to another. Flooding fields for rice production reduces pathogen survival in the soil.[1]


  1. a b c Black,L.L. (2001). Cucurbit Diseases - Alternaria Leaf Spot - Alternaria cucumerina. From Vegetable Diseases: A Practical Guide. AVRDC - The World Vegetable Center. Retrieved: 2010-08-08.