When is the best time to apply wheat herbicide

The first emergence peak and the largest emergence peak of weeds in wheat field appeared 20 days after wheat sowing, and some weeds may have a small emergence peak in March of the following year. Through a large number of experiments and observation, there are three key periods in the period of weed control in wheat field. 1. It is an important period to control weeds in wheat field after sowing and before emergence. two。 Wheat seedling stage (middle and late November) is the best time to control weeds in wheat field. 3. The period of wheat turning green (from late February to mid-March) is a supplementary period for the control of weeds in wheat fields. According to the law of emergence and growth of weeds in wheat field, and according to the species and climatic conditions of weeds in wheat field in our city, the wheat seedling stage (middle and late November) is the best time to control weeds in wheat field. First, the temperature is high at this time, the chemical absorption and conduction is fast, which can give full play to the efficacy and improve the weeding effect; second, the weeds have been basically unearthed, but the water and nutrients in the soil have not been consumed and have no effect on wheat; third, the weeds are small, the weed tissue is young, the drug resistance is poor, and the rate of death is fast; fourth, the wheat plant is small, the population is small, the weed dosage is large, the weed mortality rate is high, and the weed is weeded thoroughly. Fifth, wheat at this time strong drug resistance, generally not easy to cause drug damage, safe to wheat. To sum up, the middle and late November is the best time for chemical control of weeds in wheat fields in our city. In this period, the suitable varieties of herbicides should be selected according to the grass condition and temperature, and the herbicide should be applied in time. Commonly used herbicide varieties are: giant star, Puma, 24D butyl ester, dimethyl tetrachloronat salt, make it long and so on. The wheat fields in which weeds are not weeded in time and weeds occur seriously in mid-November can be replenished during the wheat turning green period (from late February to mid-March), but the application period should not be too late, so as not to cause drug damage to wheat. Whether it is applied before or after the year, the dosage should be strictly controlled to prevent the occurrence of drug damage.