Key points of Management techniques for ear stage of planting Maize

The ear stage of maize refers to the period from jointing to heading, which is the stage of both vegetative growth and reproductive growth. In this period, there is not only the exuberant growth of roots, stems and leaves, but also the differentiation and development of female and male ears, which is the period of the fastest growth, the largest growth and the largest demand for fertilizer and water in the whole life of maize. The main objectives of field management are as follows: the basal internodes are short, thick and full, and the female and male spikes differentiate well. The individual growth is strong, the group development is moderate and neat, and the main management measures are as follows:

First, scientific topdressing. The ear stage of corn is the period of vegetative growth and reproductive growth, in which the absorption rate and quantity of nutrients increase rapidly. in more than 20 days of the ear stage, the nitrogen absorption of summer corn accounts for 76% of the whole growth period. the absorption of phosphorus and potassium accounts for about 63% of the whole growth period, which shows that the ear stage is an important period for maize topdressing. All plots with no base fertilizer or insufficient use of base fertilizer should be topdressing at the ear stage of corn. The best period of topdressing should be 10-15 days before heading, and if the weather is dry, it can be combined with watering. Topdressing at this stage has two advantages compared with topdressing at the early jointing stage: ①, when fertilizer is applied to the soil, the basal 1-3 internodes of maize are basically fixed in length, which reduces the probability of lodging in the later stage (early topdressing is easy to promote the overextension of basal internodes); ② meets the growth needs of maize in the middle and later stage, reduces the probability of de-fertilizing in the later stage, and reduces the degree of female ear baldness and grain deficiency. Nitrogen and potassium are the main types of topdressing, and 30-40 jin of urea can be applied. If there is no potassium fertilizer or insufficient potassium fertilizer, 20-30 jin of potassium chloride or potassium sulfate should be added to meet the growth of corn and improve the ability of lodging resistance and disease resistance of stalk.

Second, do a good job in chemical regulation and control. The experimental results in recent years show that spraying plant length regulator at ear stage of summer corn can not only increase yield, but also prevent lodging. When the 7th-11th leaves of maize were unfolded, spraying 30% corn Jindele or 2% Dafeng could effectively shorten the length of 1-3 basal internodes and increase the number of aerial root layers to prevent lodging and increase yield.

Pay attention to the prevention and control of diseases and insect pests. The main diseases of summer maize at ear stage are brown spot and stem rot. Brown spot disease can be prevented by spraying 20% triadimefon with potassium dihydrogen phosphate and other foliar fertilizer in 6-8 leaves of corn, and stem rot can be prevented by spraying 200 times of 10% Shuangxiaoling before and after heading. The main pests at panicle stage are corn borer and sunflower scale. Corn borer generally occurs in the small trumpet stage and the big trumpet stage. When reaching the control target, 2.5% phoxim granules are scattered in the heart leaves, the dosage of each plant is 1ml 3g, and the control effect is good. 40% phoxim EC and other chemicals can be selected to dilute 1000 times and spray at the base of corn seedlings or irrigate roots to control the occurrence of sunflower scale.

Fourth, watering in case of drought and drainage in case of waterlogging. Maize trumpet mouth stage and silking stage is the critical period of water demand, in case of drought, it should be watered in time to promote the differentiation of female and male ear and the formation and development of male ear pollen. This period is the rainy season, torrential rain and other extreme abnormal climate is very easy to occur, in case of waterlogging, it is necessary to eliminate stagnant water in time to ensure the normal growth of corn.

Fifth, pull out small and weak plants in time. Due to sowing, soil fertility, replanting, diseases and insect pests and other reasons, some small and weak plants were produced in the field after jointing of maize. They usually do not bear ears or are very small, which not only occupy a certain amount of space, consume fertilizer and water, and affect the growth of healthy plants, but also easily cause shade and lodging caused by wind and rain, so they should be pulled out as soon as possible to ensure the uniformity of the population.

Sixth, control weeds in the field. Due to the neglect of weed control in the early stage, the plots with luxuriant weeds in the field should be weeded in time. If the weeds in the field are more luxuriant, we should first manually use wooden crawlers to hold down the weeds, and then choose paraquat to put on the protective shield to spray and control, and the selected equipment should minimize dripping, running and leakage, so as not to affect the corn.