What are you doing with pests and diseases in the corn fields now?

Due to the gap in sowing time, summer maize is now growing, sowing should be in the pollination period, and a little later is in the beginning of tasseling, jointing and later. At this stage, the diseases that are prone to occur include corn smut and black silk ear disease; Insect pests include corn borer, cotton bollworm, caterpillar, aphid, etc.

1. Corn diseases.

1. Corn powdery mildew. It is a fungal disease of maize millet black powdery mildew.

Symptoms] The aboveground parts of maize can be damaged during the whole growth period, but the symptoms are prominent in the tasseling stage. Nodules of different sizes can be produced in various parts of the plant. In the early stage, the tumor is covered with a white film, which is gray and then black.

Occurrence characteristics] Overwintering in the soil or on diseased residues and stacked straw with thick spores of the fungus. Overwintering Atsugaki spores germinate to produce microspores, which are spread by air currents, rainwater, and insects. It is harmful to invade the tissues, wounds, and insect wounds of the plants.

The formation of diseased tumors emits a large amount of black powder, which spreads to other plants and spreads to other plants. High temperature and drought, excessive nitrogen fertilizer, and diseases are prone to occur.

Control methods] (1) Mainly use carbendazim wettable powder and other agents to dress seeds before sowing. (2) Spraying fungicides for early prevention and early treatment. Prevention is the mainstay, tebuconazole, fenenethrin, prothioconazole, imimidide, etc. can be used to spray water according to the instructions.

2. Corn silk smut.

Symptoms] corn silk smut is a systematic infection disease invaded by seedlings. Most varieties do not show symptoms until heading. The florets of the male spike are all or partially damaged, and the florets are deformed and the spikelets become leaf-shaped, and the male spikes cannot be formed.

The base of the floret swells to form a gall, which is grayish-brown in color, easy to crack and emit a large amount of black powder. When the female spike is damaged, the appearance is stubby and short without filaments, except for the bract, the inside of the female spike is filled with black powder, and when it matures, the bract leaves break and emit a large amount of black powder.

Occurrence characteristics] The pathogen overwinters in the soil with winter spores, which is the main source of the disease in the second year. The effect of soil and manure on the transmission of bacteria is greater than that of seeds. Soil drought, low temperature, and slow emergence of maize are conducive to disease.

Control methods] (1) fungicide seed dressing, using 50% carbendazim wettable powder according to the weight of the seeds. (2) Spray fungicides, and use tebuconazole, fenethrin, prothioconazole, imimidide, etc. to spray water according to the specified amounts.

2. Corn insect infestation.

The main insect pests in this period are corn borer, cotton bollworm, caterpillar, aphid, etc.

Prevention and control methods] 1, pesticide control, the selection of insecticides such as acemethamidophos, dimethoate, chlorpyrifos, deltamethrin, cypermethrin, borer, acetamloprid, etc. 2. For borers, corn borers, and cotton bollworms that are bored into the buds, manually peel off the bracts at the top of the ears if necessary.

If there are pests and diseases in our corn fields, we will spray pesticides because pesticides are an effective way to control pests and diseases.

Go with the flow, this is a normal phenomenon of nature, and instead of vigorously governing, it is better to go with the flow, and you can make yourself very relaxed.

Some related pesticides can be purchased. It's best to consult a professional and they will give you good advice.

In order to effectively prevent the occurrence of corn rough shrinkage disease, seedling blight, cotton bollworm, armyworm and other pests and diseases, and ensure the full seedling and healthy growth of corn at one time, the following comprehensive control measures are recommended.

1. Appropriately postpone the sowing date of summer maize It is recommended to postpone the sowing of summer maize to about June 12 to avoid the peak period of planthopper transmission activities coincides with the susceptibility period of maize (before the 9-leaf stage of maize) and reduce the probability of susceptibility.

2. Do a good job of seed dressing with pesticides containing imidacloprid, thiamethoxam (Ruisheng) and carbofuran, which can effectively kill some planthoppers and have obvious effects on controlling the occurrence of planthoppers.

3. Concentrate on killing gray planthoppers After wheat harvest and corn emergence, continue to control twice, use 25 pymetrozine according to 15-20 grams per mu, or 50 ml of cypermethrin + 10 imidacloprid 30 grams, and spray 30-40 kg of water evenly. It is necessary to give full play to the role of professional plant protection cooperatives, implement unified control over gray planthoppers, and improve the efficiency of prevention and control.

4. Evening seedlings and seedlings Corn sowing should be appropriately increased in sowing amount, corn grows to 6-7 leaf stage, and the symptoms of coarse shrinkage diseased plants are obvious, and the diseased plants are pulled out in combination with seedlings and seedlings.

5. Armyworms can be controlled with insecticides such as emamectin benzoate, cyhalothrin, and cypermethrin.

6. For the prevention and control of fungal diseases such as seedling blight and root rot, 500 times of 50% carbendazim wettable powder, or 700 times of 70% methyl tobuzin wettable powder can be sprayed, focusing on spraying rhizomes.

7. Chemical control of weeds at the seedling stage of corn Chemical weeding should strictly select herbicides and accurately control the dosage. Before the germination of corn after sowing, 200 ml of 40% ethylene and herb suspension, or 200 ml of 42% isopromethyl herb suspension, or 100 ml of 50% acetochlor emulsifiable concentrate were evenly sprayed on the surface of the ground with 200 ml of 40% ethyl and herbaceous suspension agent.

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