Corn Pest and Disease Control Tips

In the process of cultivating corn, we will also encounter various diseases. So today I will tell you how to prevent and control corn diseases?

Corn leaf spot:

Generally, the rainfall in July is positively correlated with the incidence of small spot disease. When the diseased plant rate reaches 70%, the diseased leaf rate begins to develop from bottom to top; the earlier the rainfall, the earlier the diseased plant rate rises; otherwise, it will be late. When the diseased plant rate is 70% and the diseased leaf rate is 20%, if there is moderate to heavy rain, it will break out in about 15 days. When the diseased plant rate is 100% and the diseased leaf rate is 30%, and there is continuous rainy weather, prevention and control should be carried out. First, remove 1-2 diseased leaves at the bottom of the corn and destroy them together; spray 50% carbendazim or 70% thiophanate 500 times solution, or 800 times solution of mancozeb, etc.

Corn leaf spot:

Select the main local varieties and corn fields with good growth, take samples at five points, and check the number of diseased plants, the number of leaves per plant, and the severity at each point. Generally, when the diseased plant rate reaches 100% and the diseased leaf rate reaches 30%, prevention and control can be carried out when there is rainfall. You can spray 12% green milk copper, etc. Corn round spot disease:

Select disease-resistant varieties, take samples at five points, check 10 plants at each point, and check the disease rate and the number of diseased leaves per plant. Generally, spray pesticides for prevention and control during the peak period of fruiting and silking, using 500-800 times diluted 25% triadimefon.

Corn smut:

If a tumor is found, it should be removed promptly.

Corn virus disease

There are corn dwarf mosaic and dwarf mosaic diseases (mosaic stripe disease). The virus is transmitted by gray leafhoppers and aphids. The number of gray leafhoppers and aphids in the field is closely related to the number of weeds in the field, and the number of gray leafhoppers and aphids carrying the virus is related to the severity of wheat bush dwarf disease. Therefore, the degree of corn virus disease can be judged according to the degree of wheat bush dwarf disease. In terms of prevention and control, weeds and insect control are mainly used to prevent the serious occurrence of corn virus disease. In the field survey, if suspected diseased plants are found, they should be removed immediately and sprayed with disinfectants, such as 5% fungus and virus clearing.

Corn Borer:

Pay attention to the hatching difference of eggs in the field and the damage of larvae, and seize the critical period to spread granules to control the first generation of corn borers. Granules made from Bt emulsion or Beauveria bassiana granules can be spread into the corn bell to kill the newly hatched larvae.

Corn moth:

The main pest in corn fields is the red-margined moth. In late July, we started to investigate the number of eggs and larvae on 100 plants. When we found that there were two eggs on 500 corn plants, or more than 15% of the ears were bitten, we immediately started prevention and control. The newly hatched larvae of the moth have the habit of concentrated damage. There are more larvae after the corn is silked. We can organize manual catching of the insects or spray pesticides for prevention and control.