Cucumber powdery mildew

1. Symptoms In the early stage of cucumber powdery mildew, white powder spots appear on the front or back of the lower leaves, and then expand into round powdery spots. Under suitable conditions, the white powdery spots continue to expand, connecting into pieces, becoming a large white powder area with irregular edges, and spreading the entire leaves, like a layer of white hair, so it is commonly called white disease. At the end of the disease, the white hair turned grayish white, and the whole leaf was yellowish brown.

 

2. Prevention and treatment methods

 

2.1 Selection of resistant varieties.

 

2.2 Seed disinfection: soak seeds with 1% anti-cumin suspension 20ml and 10kg water for 1h, and eradicate the powdery mildew on the seeds.

 

2.3 Cultivation management 1 Thoroughly eliminate weeds and residual plants in the shed to prevent parasitic bacteria; 2 bed soil can be disinfected with 50% carbendazim and other drugs; 3 cucumber seedlings should be watered as little as possible after planting to prevent lengthening. Control the amount of nitrogen fertilizer applied, pay attention to the application of phosphorus and potassium fertilizer. During the melon period, the amount of fertilizer and water can be increased, and the leaf surface micro-fertilizer can be sprayed at appropriate time to prevent premature senescence of the plant and enhance the disease resistance of the plant. 4 diseased plants or diseased leaves were removed in time.

 

2.4 Chemical control 70% methyl thiophanate WP 1000 times solution, or 15% rust rust 1000-1500 times solution, or 75% chlorothalonil WP 500-800 times solution, spray once every 7 ~ 10d, Spray even 2 to 3 times. (From: Zhejiang Agricultural Network)