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Cucumber Target Spot and Anthracnose: Fungicide and Cultural Control

White/brown spots spreading on cucumber leaves, stunting vines and fruit, are likely target spot (Corynespora) or anthracnose (Colletotrichum)—both fungal. Sevin and rotenone are insecticides and ineffective against fungi.

Effective Management

Apply chlorothalonil (Daconil, Fertilome Multi-Purpose Fungicide) at first sign; repeat per label.
Water at soil level (drip irrigation); keep foliage dry.
If overhead watering, do so early morning for rapid drying.
Remove and destroy spotted leaves before spraying.
Rotate cucumber location next year; avoid planting in same spot.

Fungicides need 2 hours dry time on leaves. Preventive sprays work best in humid climates.

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