Prevention and treatment drug for downy mildew of rheum officinale

The invention discloses a prevention and treatment drug for downy mildew of rheum officinale, and belongs to the field of agricultural pesticides. The prevention and treatment drug is prepared from the following raw materials in parts by weight: 0.5 to 1 part of borax, 1 to 2 parts of urea, 1.5 to 3 parts of monopotassium phosphate, 1 to 2 parts of sodium bicarbonate, 0.1 to 0.5 part of chlormequat chloride, 20 to 30 parts of cyclodextrin, 5 to 15 parts of sodium alginate, 10 to 30 parts of a 50-percent chlorothalonil wetable powder, 20 to 30 parts of dandelion, 20 to 30 parts of honeysuckles,20 to 30 parts of herba erigerontis, 20 to 30 parts of sierra salvia, 20 to 30 parts of sophora alopecuroide and 20 to 30 parts of bidens bipinnata. The prevention and treatment drug for the downy mildew of the rheum officinale is outstanding in pesticide effect, long in lasting period and pollution-free; the prevention rate for the downy mildew of the rheum officinale is 97 percent or above, andthe effective curing rate