Occurrence and control of weeds in summer sowing corn field
I. Occurrence and damage of weeds in corn fields China is a major producer of corn in the world. The annual planting area is about 300 million mu. Huanghuaihai region is the largest summer corn planting area in China. Most of the cultivation methods are wheat-corn two crops a year, and most of the planting patterns are seeding or shoveling. The main weeds in the corn field include crabgrass, goosegrass, barnyardgrass, purslane, amaranthus, field bindweed, alfalfa, teff grass, green dogtail, aconite, yarrow, and so on. In normal years, the damage caused by weeds can reduce the yield of corn by 1 to 20%, and when serious, it can reduce the yield by 3 to 50%. The vitality of weeds in corn fields is extremely strong, and some seeds can still germinate in the soil for 20 years, such as aconite, Chinese wolfberry, Chinese wolfberry, purslane, and convolvulus. General weeds have the characteristics of early maturity, irregularities, and segmented emergence, which are not conducive to prevention and control, and many weeds can be revived, especially perennial weeds, such as purslane after drying in the field for 3 days after manual removal. Rain can still resume growth. In addition, weeds have an amazing ability to reproduce. Most of the weed species are several times, several hundred times, or even tens of thousands times more than the crop. According to the survey, there are about 220,000 seeds of a crabgrass, showing how strong their reproductive ability is. II. Control of Weeds in Summer Maize Fields Summer sowing of maize in the Huang-Jin-Hai area has two planting methods: one is no-tillage sowing, and the other is ploughing live. Tillage cultivation is carried out after harvesting of the upper glutinous wheat, ploughing with a rotary plough, etc., and then leveling the land to sow corn. In this kind of farmland, the weeds excavated before harvest are removed due to the turning of the soil layer after wheat is harvested. The weeds and corn emerge at the same time after sowing. As long as the soil moisture is suitable, the general soil sealant can be used for pre-emergence soil treatment to achieve an ideal weeding effect. At present, the varieties of herbicides commonly used in production include Xuanhuayi A, corn treasure, and so on, which have a good effect after application. For the past more weed species, can be used to deal with the baby; for aconite or barn grass more fields, can be used Jin Yi A soil treatment. No-tillage corn can be divided into two types: one is to intercropping maize between wheat ridges before harvesting; and the other is to directly sow corn after wheat is harvested in the field. Irrespective of the type of planting method used, most of the farmland has a portion of weeds unearthed before the wheat harvest. This part of the weeds is “passed†to the corn field after the wheat is harvested. Before and after summer corn sowing is in high temperature and rainy season, when weeds grow rapidly, big grasses and new grasses often pose a threat to the growth of corn seedlings. In general, the use of Gramoxone, wildfire and other herbicides to eliminate large grasses , And then use the soil to seal off the herbicides such as A, Corn Po equal to soil treatment before seedlings after sowing, but also can be used immediately to block the killing, a drug to block the double effect. Weeds can be used for soil sealing treatment for fields with more types of weeds, and can be treated with new Xuanhuayi Ah in the case of high weeds, and can be used for soil closure in fields where there are more aconite roots. After the planting, the fields with poor soil treatment or soil sealing and heavier weeds before the seedling planting can be controlled by Yubao and Yubei. Yubao and Yubei are more convenient when applied, and they can be used for herbicides without having to wait for rain. They can still exert good efficacy under drought conditions. For a lot of aconite roots, aconite clearing can be used to spray between rows. Fuziqing not only has good control effect on Aconite, but also can cure other broad-leaved weeds. Chemical weeding has been accepted by the majority of farmers because of its advantages of being fast, efficient, and easy to operate. Especially in the summer maize growing season, due to the rapid growth of high-temperature, high-moisture weeds, coupled with the often rainy weather, artificial and mechanical control difficulties, we should strongly promote chemical weeding. However, if the type of herbicide is not properly selected, the method or period of use is unsatisfactory, it will result in poor control or even adverse effects such as injury. Therefore, it is hoped that farmers' friends will choose the herbicide varieties correctly, use scientific techniques and methods of use, and master the application period so as to achieve the purpose of safety, effectiveness, and productivity.