Maize rust (Puccinia polysra) is a disease that occurs in the middle and late period of maize growth in Northeast China, Northwest China, North China, East China, South China and Southwest China. It is serious in some places or in some years, and harms maize and maize plants. 1 v8 c！ C 1 the disease mainly infects leaves, and in severe cases, it can infect bracts, fruit ears and tassels. At the beginning of the disease, the leaves are scattered or aggregated with yellowish spots on both sides. Later, it swelled out and became round, brown or brown, and the surrounding epidermis turned up, releasing rust-colored powder, that is, the summer spores of the pathogen. In the later stage, a round black protuberance grows on the lesion, and after rupture, dark brown powder is exposed, that is, the pathogen winter spore. ?

1 chemical control. At the initial stage of the disease, use 1500 times of 20% triadimefon emulsifiable concentrate or use 0.2 degree sulfur mixed solution to spray evenly. When the condition is serious, spray it every 15 days 1 time.

2. Rational fertilization, increasing the application of phosphorus and potassium fertilizer, avoiding partial application of nitrogen fertilizer, promoting healthy growth and improving disease resistance.