Safety management of leek in greenhouse and prevention of epidemic disease

Harm symptoms: mainly harm pseudostems and bulbs, leaves, roots, flower sprouts can also be affected. The disease spots of the affected leaves mostly started from the lower part, initially producing dark green water-stained disease spots, and later extended to about 1/2 of the leaves, the whole leaves turned yellow, drooping and soft rot. When wet, the diseased part produces a gray mold. Pseudostems damaged, water-stained light brown soft rot, leaf sheath easy to peel off. When bulbs were damaged, the root disk was water-stained light brown to dark brown and rotted. The internal tissues of bulbs were light brown when cut longitudinally, and their growth was inhibited. The roots were brown and rotted, the root hair was obviously reduced, the water absorption was affected, the life of the roots was short, the new roots were rarely produced, the growth potential was obviously weakened, and the life was shortened. Control methods: 1. 5% chlorothalonil dust, 667 square meters each time with 1 kg, 7 days spray prevention. 2. At the early stage of disease, 60% metalaxyl copper WP 600 times solution, or 40% Synergistic Rudumei WP or 500 times solution of metalaxyl copper WP, or 72% Kelu WP or 72.2% Prolik aqueous solution 800 times solution, or 50% Anke WP 2000 times solution, or 72% Kelaxyl WP or 72% Kekangling WP 600 times solution, Or 58% metalaxyl manganese zinc wettable powder or 58% redoxyl manganese zinc wettable powder 400 times solution, or 90% pyrimethamine wettable powder 500 times solution, or 60% succinate·ethyl phosphine aluminum wettable powder (DTM) 100 times solution, or 72% propamocarb aqueous solution 800 times solution, spray once every 7 days, alternate application of drugs for 3 times.