Diseases

 Important diseases of cucumbers include the papaya ringspot virus, zucchini yellow mosaic, watermelon mosaic, cucumber mosaic, angular leaf spot, anthracnose, damping-off (Pythium and Rhizoctonia root rot), leafspot, downy and powdery mildews and scab. Once a disease has infested a crop, remedial action can be taken, but it is usually already to late to prevent serious losses. Field and seed selection, seed-treatment, rotations, water management, weed control, insect control, and other recommended sanitation practices and chemical treatments should therefore be combined in a disease management program to prevent disease attacks in cucumber. Seed treated with a fungicide can protect the field from serious yield losses. Pay close attention to fungicide application techniques. Coverage of all sections of the field is important since unprotected spots may become undesirable sources of inocolum. Fungicide sprays are usually an integral part of cucumber production even when planting disease resistant cultivars. Disease control has been improved when fungicide treatments were initiated at the two true-leaf stage. Other diseases of cucumber include wet rot, Choanephora cucurbitarum; Alternaria leaf blight, Alternaria cucumerina; Cercospora leaf spot, Cercospora citrullina; Sclerotinia stem rot, Sclerotinia sclerotiorum; and Target leaf spot.