Method for controlling downy mildew of organic cucumber

The invention discloses a method for controlling downy mildew of organic cucumber, and belongs to the technical field of agricultural plantation. In the prior art, a conventional cucumber downy mildewcontrol method has the problems that the drug delivery method is single and drug resistance is generated easily. In order to solve the problems mentioned above, a physical control method and a chemical control method are combined. The provided method comprises following steps: pretreatment before downy mildew, environment control, and treatment in downy mildew. On the basis of nano cuprous oxidepretreatment, ethylicin and pyraclostrobin are dissolved in missible oil (cyclohexanone and light aromatic hydrocarbon solvent naphtha), thus the medicinal liquor can be better adhered on the leaf surface and penetrates into the plant epidermis or penetrates into bacteria and insects, and the control effect is greatly enhanced. Plant originated antibacterial substances are used to replace part ofchemical antibacterial agen