At present, most farmers are accustomed to using chemical herbicides to control weeds in wheat fields in the spring. In fact, chemical weeding is better before winter than in winter, and the operation is simpler and easier.

 

The benefits of chemical weeding before winter:

 

1. The dosage is small and the cost is low. When weeding before winter, the small amount of weeds is small, the control is simple and labor-saving, and the cost of medication can be reduced;

 

2. The coverage of weeds by wheat seedlings is small, the wheat seedlings are not sealed before winter, the canopy is small in the field, the weeds are bare, and the medicine surface is large;

 

3. The control effect is good. The weed tissue is young and warm before winter, and the drug resistance is poor, which can improve the control effect;

 

4. The safety of the crops is high, and the herbicide is used before winter. The decomposition time of the liquid is long, so the safety of the crops is high;

 

5. High spraying efficiency, chemical weeding before winter can solve the problems of walking difficulty in spring weeding, low spraying efficiency and difficult quality assurance.

 

 

Operation method:

 

1. Choose the best prevention time

 

From mid- November to early December , wheat seedlings grow to 4 leaves, which is the best time for weeding in wheat fields. At this time, most of the weeds have just been unearthed, the drug resistance is poor, and the control effect is good. One application can basically control the weeds in the whole growth period, and the application time is small, the herbicide residues are small, and the impact on the post-crop crops is also small. However, when the herbicide is used at low temperatures in winter, the herbicide is obviously longer than the herbicide at high temperature, and it usually takes 12 to 15 days for the grass to appear. In the summer high temperature stage to control the foxtail of farmland, the whole field weeds will generally die within 5 to 7 days. Therefore, be patient after the medication, as long as the timing is well grasped, the liquid is sprayed in place, generally do not need to re-medicate.

 

2. Strictly control the dosage

 

Water should be added strictly according to the dilution factor. Do not reduce the amount of water at will. When spraying, pay attention to thoroughness, uniformity, no heavy spray, no leakage, all weeds should be sprayed with herbicides, otherwise it will be in vain; if the amount of herbicide is too large, it will cause phytotoxicity and pollution. It even has an adverse effect on the crops after the crop; if the dose is too small, the effect on weed control is poor, and it does not play the role of weeding and wheat. Therefore, when the herbicide must be strictly controlled doses, generally acres dosage of 30 to 40 kg.

 

3. Focus on the quality of spraying

 

When using herbicides, it must be carried out in strict accordance with the technical operating procedures. Due to the low temperature in winter, it is often accompanied by strong winds, which is not conducive to the exertion of the efficacy. Therefore, it should be applied at a relatively high temperature during sunny days. At this time, the physiological metabolism of weeds is relatively strong, which is conducive to the conduction of the medicament in the weeds, and it is easy to receive a better herbicidal effect. For example, after entering December , the wheat field is controlled by weeds (spermazole), which is basically difficult to kill weeds, especially herbicides such as isoproturon, which cannot be used when the temperature is too low. It should be used when the temperature is above 10 °C. Spraying time too early or too late can also cause pesticides to fall into the ground, causing waste and polluting the soil. At the same time, the long-lasting herbicides chlorsulfuron-methyl and metsulfuron-methyl should be banned. These two pesticides are susceptible to phytotoxicity to the crops after use in wheat fields.