What should I do if corn is not dysplastic?

A recent field survey found that some of the field corn (2325, 3.00, 0.13%) had small spikes, few branches, or no branches, some of which could not be extracted, and there was no pollen or pollen in Tiansui. Phenomenon, diagnosed as corn top rot. If the prevention and control measures are not taken in time, the corn is poorly pollinated, bald or flowery, which seriously affects the yield.

First, the characteristics of occurrence

Corn top rot is a new type of disease that has occurred in recent years and can occur from the seedling stage to the adult stage. The main performance in the later stage is that the leaves under the ear are white and dry, the ear is small and the branches are few, or there is no branching, and there is no pollen or pollen in the ear. Plants that are susceptible to disease can be firm, but the ears are small and the seeds are less; the severe tassels are aborted, deformed and unable to head, or form empty stalks. The disease can occur in the whole growth period of corn, but it is most obvious before and after heading. The pathogen is mainly composed of soil, diseased bodies and seeds, especially the seed-borne bacteria can spread long distance, so that the diseased area is expanding continuously; and the pathogens produced by the diseased plants can also be re-infected with the wind and rain. Generally, it is beneficial to occur under conditions of heavy rain and high humidity, and the suitable temperature for the onset is 25 ° C to 30 ° C. Generally, the soil is sticky, the terrain is low, the watering is too large, and the watering is too early, especially in the years when the rainfall is too much, the soil and air humidity are relatively large, which is conducive to the occurrence of diseases.

Second, prevention and treatment methods

1. Chemical control. In the early stage of the disease, the choice of chemical control can be controlled by 50% carbendazim WP 500 times solution, 70% thiophanate-methyl WP 600 times solution, or 75% chlorothalonil WP 800 times solution. Control once every 5 to 7 days, continuous control 2 to 3 times.

2. Foliar fertilization. Combined with chemical control, foliar application of potassium dihydrogen phosphate, humic acid foliar fertilizer, brassinolide and the like. In order to supplement nutrients, promote the recovery of growth, cultivate strong strains, improve the ability to resist stress, and try to recover losses.

3. Cut leaves to promote the ear. For the heavier diseased plants whose heart can not be properly extracted from corn ears, the leaves above the tassels can be cut with scissors to facilitate the normal heading of the tassels, and the cut disease leaves will be taken out of the field. Buried treatment.

4. Artificial pollination. For plots with milder onset, pull the pollination with a drawstring. That is, two 2 m long bamboo poles and a hemp rope slightly longer than the ground width are used, and the two ends of the hemp rope are respectively attached to the top of the bamboo pole. Two people stand at the two ends of the ground, while holding the rope, walking parallel in the same direction, the height of the hemp rope should be 20 to 30 cm under the ear, which helps the corn pollen to spread and fall on the ear; For the plots with heavier onset, it is necessary to borrow powder from nearby disease-free plots and carry out artificial supplementary pollination. One is to pick up powder at the right time. In the sunny days without wind or breeze, after the dew is dry, it is generally appropriate to pick up the powder after 9:00 am and 11 noon, and the cloudy days can be extended to the afternoon. When collecting powder, hold a plastic (11060, 70.00, 0.64%) bucket in one hand, and pinch the tassel with the other hand and gently shake it to shake the pollen into the bucket. Do not use metal utensils as a powder collector and pollinator to avoid reducing pollen vitality. The second is to choose a pollination plant. Pollination should be selected from fresh filaments, and there is no fertilized corn hammer. If the filament is too long, it is not conducive to fertilization. The filament should be cut short, leaving only about 1.5 cm to facilitate pollination; if the filament is brown and wilting, stop growing, indicating that Fertilization, no need to pollinate. The third is to make a pollinator. Use bamboo or cardboard tubes with a radius of 2 cm to 3 cm and a length of 15 cm to 20 cm. One end of the barrel is sealed with 3 to 4 layers of gauze, or a layer of velvet, and the collected pollen is loaded into the barrel. The fourth is pollination. Point the pollinator to the filament on the poorly polluted corn hammer and gently bounce it to shake the pollen onto the corn silk.