Management techniques of ear stage of Maize

The whole life of maize can be divided into three stages: seedling stage, ear stage and flowering stage. Ear stage refers to the growth stage from jointing to heading, and ear stage is the period of vegetative growth and reproductive growth of maize plants. The ear stage is the key period in which maize grows fastest, grows the most, and needs the most fertilizer and water. The requirement of nitrogen, phosphorus and potassium accounts for about 65%, 55% and 85% of the whole growth period, and water demand accounts for about 30%. At this stage, the central task of field management is to promote strong leaves and culms, many ears, large ears, not only to ensure strong plant growth, but also to ensure good ear development, to achieve strong individual development, population growth moderate, neat high-yield appearance.

Most of them entered the growth stage of panicle stage in the middle of July. in order to resist disasters and win a bumper harvest, the following key points of field management of panicle stage were put forward.

The main results are as follows: 1. timely and appropriate amount of topdressing panicle stage is the maximum efficiency period for maize fertilizer demand. therefore, all plots with insufficient use of topdressing or basal fertilizer at panicle stage should be topdressing corn ear fertilizer in time. Especially under the current condition of straw returning to the field, topdressing can be applied as early as possible, and the amount of topdressing can be determined according to the nitrogen application amount set by the target yield, generally applying urea 20kg per mu, artificial strip application or mechanical strip application into the soil to meet the water supply in time after fertilization to facilitate the exertion of fertilizer efficiency.

Second, timely irrigation and drainage of corn should be irrigated twice at the ear stage. Before and after the big trumpet mouth for the first time, it is the suitable time for topdressing, so irrigation should be combined with topdressing to give full play to fertilizer effect, promote aerial root growth and enhance photosynthetic efficiency. For the second time, the amount of irrigation was increased appropriately before and after heading. Before and after heading, it is easy to have high temperature and summer drought weather, neck drought, and pollen abortion caused by high temperature and drought. Therefore, once there is a drought before and after heading, it should be irrigated in time. Although more water is needed at the panicle stage, excessive soil moisture affects maize root growth and reduces yield, so it should be drained in time in case of waterlogging to keep soil moisture at 70% to 80% of the maximum field capacity.

Third, integrated control of diseases and insect pests the main pests at ear stage are corn borer and so on. The damage period of the second generation of corn borer in our city began in mid-late July, which was the big trumpet period of most summer corn. The corn borer mainly eats the leaves in the heart leaves (trumpet mouth) at the ear stage, eats the female ear from the male to the silking stage, and drills the straw, ear shaft and ear stalk after the corn begins to bear fruit. Therefore, the best time to control Ostrinia furnacalis is the big trumpet stage, and it will be very difficult to control it after heading. Corn borer control method is in the big trumpet mouth perfusion, the use of phoxim and other granules or Bt emulsion 100g 150ml plus fine sand 5kg in the heart leaf control. Drill 5 or 6 small holes in the plastic bottle cap of Coke or Sprite (to be able to leak the drug particles), fill the granular medicine in the bottle and tighten the bottle cap; when filling the heart, turn the plastic bottle upside down and aim at the corn trumpet mouth, gently shake off the medicine with your hand. Where possible, high-pressure mercury lamps can also be used to trap and kill adults, or release Trichogramma in the field for control. Spray such as Kangkuan or tebufenozide can also be used to control corn borer. The main diseases of summer maize at ear stage are brown spot, stem rot and so on. Brown spot disease can be controlled by spraying 20% triadimefon with potassium dihydrogen phosphate and other foliar fertilizer in 6-8 leaves of corn, and paying attention to spraying the top cover and leaves evenly; stem rot can be sprayed with agricultural streptomycin 4000-5000 times or 77% wettable powder at the initial stage of the disease.

Fourth, the remedial measures after lodging the lodging before and after jointing generally do not need to be lifted manually. Most of the corn lodged before jointing was soaked and lodged by Rain Water after excessive rainfall and waterlogging. As the recovery ability is very strong at this time, as long as the accumulation of water in the field can be excluded. After jointing lodging, the plant can also naturally restore upright, does not affect the normal pollination and fruiting in the future, and allows it to recover by itself. The lodging maize plants before and after pollination are tall, and the plants overlap with each other after pollination, so it is difficult to recover naturally, which will not only affect the photosynthesis, but also affect the normal growth and development, silking and pollination. When lifting up, it should be early, slow, light, and fixed in combination with soil cultivation. After the lodging occurs, it should be picked up in a surprise attack within 1-2 days. Part of the root system of corn has been damaged when lodging. When straightening, it is best for two people to work together, one of whom grabs the upper part of the corn plant and gently pulls it up, while the other cultivates the soil at the root. Once the plant bends and grows upward, it can no longer be supported. And topdressing in time to restore the growth of corn as soon as possible, topdressing 5kg urea per mu.

Fifth, other field management due to sowing, diseases and insect pests and other reasons, resulting in maize jointing, some small plants, weak plants in the field. They usually do not bear ears or are very small, which not only consume fertilizer and water, but also affect the growth of healthy plants, so small and weak plants should be pulled out as early as possible to ensure population uniformity. Due to the early prevention and control of weeds is not timely, resulting in the luxuriant growth of weeds in the field, but also combined with topdressing timely ploughing and weeding; paraquat can also be used to wear a protective shield in the directional spray control between rows, and the selected equipment can reduce dripping, running and leakage as far as possible. so as not to affect the corn.