The average yield per mu of corn in Central Plains 1500 kg. 20 15 once met a big corn grower. Corn grew well in the early stage, and after pollination, it encountered a big outbreak of rust. Because the corn grew tall and could not be sprayed manually (at that time, it was not popularized by plane), so I gave up the treatment. At the final harvest, the yield per mu was less than 900 Jin.
This is the consequence of not preventing and controlling corn rust in time!
Occurrence regularity of maize rust The pathogen of maize rust is Puccinia maydis, which mainly occurs on leaves, bracts and stems. It first occurred on leaves, and gradually spread to stems with the development of the disease.
At the beginning of the disease, pale white or gray spots will appear on both sides of corn leaves, with yellow halo around them, which is easy to identify. Then gradually develop into light yellow or reddish brown convex lesions, scattered or gathered, round or oblong, mostly oblong. In the later stage, the lesion becomes dark brown, that is, the winter spore pile.
Puccinia maydis overwinters as a diseased plant, and under suitable climatic conditions (temperature 20℃~30℃, humidity above 90%), it begins to get sick in spring. It first infects corn leaves, producing reddish-brown summer spores, and then spreads with the wind for reinfection.
The reason why corn rust is getting worse year by year is that it is getting worse year by year, which is inseparable from returning straw to the field.
Puccinia pedunculata can exist on maize plants and leaves for a long time. When these infected strains are treated in gold soil, these pathogens will exist for about 3 years. When the conditions are not suitable, it is dormant, and once the climate is suitable, it quickly germinates and infects.
When corn is planted on this land again, Puccinia pedunculata will follow its own infection law and start a new round of rust disease. Therefore, to some extent, it is the return of straw to the field that leads to the increase of corn rust year by year.
Chemical control scheme of maize rust Although maize rust occurs rapidly, its control scheme is not complicated, and it is mainly divided into prevention scheme and treatment scheme.
1, prevention and control scheme of corn rust: pyraclostrobin can spray 750 times to 1000 times on the small horn mouth and the big horn mouth of corn for prevention;
2. Treatment scheme of corn rust: Once the disease occurs, it can be sprayed with hexaconazole 1000 times or propiconazole 1000 times or tebuconazole 2000 times, and the treatment effect can be very good.
The most effective way to control the occurrence of rust is to plant rust-resistant maize varieties. In recent years, Denghai series and Dika series belong to rust-resistant varieties. We can go to the regular corn seed sales point to buy, and don't believe those illegal seeds advertised in the village.