Diseases of Cucurbits

Angular Leaf Spot Pseudomonas syringae pv. lachrymans All; most serious on cucumbers Seed-borne Infested crop residue Splashing water, insects & mechanically Clean seed Resistant cultivars Crop rotation (2 years) Copper fungicides

Downy Mildew Pseudoperonospora cubensis All cucurbits Windborne, rain-splash & mechanically Favored by warm days with cool nights leading to dew periods of rainfall with prolonged leaf wetness Resistant varieties (cucumber) Fungicides

Powdery Mildew Spaerotheca fuliginea & Erisyphe cichoracearum All cucurbits Windborne Favored by warm, dry days with cooler nights Resistant varieties Fungicides

Anthracnose Colletotrichum orbiculare Primarily cucumbers, melons and watermelons Survives on infected crop residues Can be seedborne Wind & rain splash Resistant varieties Clean seed Destroy crop residue Fungicides Crop rotation (1 year)

Gummy Stem Blight Didymella bryoniae (Phoma cucurbitacearum) All cucurbits Survives on infected crop residues Can be seed-borne Wind & rain splash Destroy crop residue Treated seed Fungicides Crop rotation (2 year)

Fusarium Wilt Fusarium oxysporum f. sp. niveum David Langston University of Georgia Watermelon Soilborne Avoid fields with a history of the disease Crop rotation (3-5 years) Resistant varieties

Bacterial Wilt Erwinia tracheiphila All but watermelon; most serious on cucumbers and pumpkins Survives in asymptomatic weed hosts (?) Insecticides Rogue infected plants

Papaya Ringspot Virus type W (PRSV-W)

Watermelon Mosaic Virus (WMV)

Zucchini Yellow Mosaic Virus (ZYMV)

Cucurbit Viruses (potyviruses) All cucurbits Survive in a variety of weed hosts Aphid-transmitted in non-persistent manner Resistant varieties Mineral oils Reflective mulches