Prevention and control methods of the ten most common corn diseases

In addition to being edible, corn is also an excellent feed for the development of animal husbandry and an important raw material for the light industry and pharmaceutical industry. Diseases are the main disaster affecting corn production, with annual losses of 6% to 10%. Here are some methods for preventing and controlling the top ten common corn diseases.

1. Corn root rot

Corn root rot is a disease caused by Pythium, which is mainly manifested by the gradual browning, softening and rotting of the mesocottage and the entire root system, and severe obstruction of root growth; the plants are short, the leaves turn yellow, and the seedlings die.

Prevention and control methods: Prevention is the main approach. After the disease occurs, strengthen cultivation management and spray foliar fertilizer . In areas with high humidity, cultivate the land for moisture dispersion to promote root growth and development. In areas with severe disease, 600 times diluted 72% mancozeb and cypermethrin wettable powder can be used.

2. Corn top rot

The symptoms are that the upper and middle leaves of the diseased seedlings lose their green color, become deformed, wrinkled or twisted; the marginal tissues show yellow stripes and knife-like notches or the leaf tips die.

Prevention and control methods: In the early stage of the disease, you can use 50% carbendazim wettable powder, 80% mancozeb wettable powder, 5% fungicide water-cleaning agent, 72% agricultural streptomycin soluble powder and other fungicides to spray on the heart. Twisted heart leaves need to be cut open longitudinally with a knife.

3. Corn Rough Dwarf Disease

Dwarf disease usually occurs when corn has 5-6 leaves. The diseased seedlings are dark green, the internodes are shortened, the leaves are stiff, wide, short and thick, and the plants grow slowly and become dwarfed.

Prevention and control methods: Prevention is the main approach. If there is no effective rescue measure after the disease occurs, apply more organic fertilizers and phosphorus and potassium fertilizers to improve the plant's disease resistance.

4. Cutworms and mole crickets

They feed on the tender stems of plants near the soil surface, causing the plants to wither and die, resulting in missing seedlings and broken ridges, or even destroying the seedlings and requiring reseeding, which directly affects production.

Prevention and control methods: Use Watson's Knife-4.5% highly effective chlorpyrifos microemulsion 30g/barrel and add water to spray evenly.

5. Corn rust

Corn rust mainly attacks leaves, and in severe cases may also occur on cob bracts and male flowers. The disease is more serious on the leaves in the middle and upper parts of the plant. Initially, there are scattered or clustered inconspicuous light yellow spots on the front of the leaves, which then bulge out and expand into round to oblong, yellowish brown or brown. The surrounding epidermis turns up and emits rust-colored powder.

Prevention and control methods: Use Watson's Rust Fighter-30% Oxythromycin·Tebuconazole suspension 20ml/barrel and add 15kg of water and spray evenly.

6. Corn borer

The corn borer is a pest that damages corn. It can damage the above-ground parts of corn plants at all growth stages, including feeding on leaves, ears, and tassels, and boring into the stems, causing damage to plant growth and a 10% to 30% reduction in yield.

Prevention and control methods: Use 20g/mu of Langtong-20% biphenyl·chlorfenapyr suspension and spray evenly with water. Or add 25-50ml/mu of Watson's General-1.14 Emamectin Benzoate EC to water and spray evenly.

7. Corn Sheath Blight

The disease is caused by a fungus, the pathogen being the Rhizoctonia solani of the subphylum Ascomycetes. The pathogen overwinters in diseased debris or in the soil. The overwintering sclerotia and diseased debris scattered in the field, and incompletely decomposed infected corn stalks used as fertilizer are the primary sources of infection for corn sheath blight. The main disease period is from the formation of corn sexual organs to the filling stage, and the disease is less serious in the seedling stage and the late growth stage.

Prevention and control methods: Remove diseased remains and sclerotia. Remove the diseased leaves at the early stage of the disease and apply the medicine to the leaf sheaths and other affected parts. Use Watson's Multi-Harvest-25% tebuconazole emulsion, spray evenly at 30-60 grams per mu, to prevent and control corn sheath blight, leaf spot, smut, etc.

8. Corn virus disease

The disease is generally spread by gray leafhoppers and aphids. If weeds appear in the corn field, the disease is likely to occur.

Prevention and control methods: Pay attention to weed removal. If suspected diseased plants occur, they should be removed immediately and sprayed with disinfectants for control, such as 5% fungicide.

9. Corn leaf spot

Generally speaking, small spot disease is likely to occur after rainfall, and it will break out about 15 days after the rainfall.

Prevention and control methods: Spray 50% carbendazim or 70% thiophanate-methyl 500 times solution or 800 times mancozeb solution for prevention.

10. Corn Smut

The disease mainly harms corn ears and tassels. Once the disease occurs, corn grains will be lost, causing huge economic losses.

Prevention and control methods: Choose disease-resistant varieties for crop rotation, generally a three-year rotation, which can effectively reduce the occurrence of diseases. Deep plowing the soil can reduce the source of bacteria in the soil and reduce diseases. Diseased corn plants should be removed or burned in time.

That’s it