The corncob began to rot from the middle part, and there were yellow spots on the surrounding leaves. . What is the reason and how to treat it? What medicine can cure it?

Corn top rot can be divided into fungi and bacteria (Fusarium top rot and bacterial top rot). At the seedling stage, the diseased plants grow slowly, the stem base turns gray, brown and black, the leaf edge turns green, yellow stripes appear, the leaves shrink and twist, and the seriously ill seedlings wither and die. In the middle and late stage of plant growth, only the main vein remains after stem rot, and the middle and upper parts are intact but deformed, showing a cattail leaf fan shape. After that, the top of the new leaves rotted, the tip of the leaves was short, dead or incomplete, and the edge of the leaves often had knife marks and yellow stripes. Cut the leaves to promote the ear, peel off the seriously ill plants with twisted and rotten heart leaves by hand or remove the heads with scissors. Bacteria can be sprayed with streptomycin or diclofenac. Fungal ones can be sprayed with carbendazim or thiophanate methyl every 7 days.