When is the best time to play herbicide in spring? How to choose herbicides?

The occasion of the year lies in spring, which is the season of sowing and the season of weeds. Weeding in spring is of great significance to ensure a bumper harvest throughout the year. Herbicide is an effective drug to kill weeds, the use of herbicides can help the growth of crops. So when is the best time to use herbicide?

When is the best time to spray herbicide in spring?

Through field investigation and monitoring, in wheat production, the effect of chemical weeding before winter is better than that in spring. At present, spraying should be done early to kill insects. This is because there are two peak periods for the growth of weeds in wheat fields.

The amount of weeds unearthed before winter accounts for more than 90% of the total weeds, and less than 10% in the coming year, and the weeds unearthed after the year are covered by wheat seedlings and their growth is weak, so they have relatively little effect on the growth of wheat. When the weeds are applied before winter, the rows of wheat seedlings are not closed, the exposed area of weeds is large, the drug resistance is poor, the dosage is low and the cost is low, which is about 23% of the cost of conventional herbicides in spring. The safety interval of medication before winter is long, which is safe for the next crop, and can prevent drug damage from adjacent sensitive crops; perennial weeds are unearthed in autumn and wheat at the same time to compete for nutrients, and weeding before winter can promote wheat to absorb more nutritions. it is beneficial for wheat to form strong seedlings and increase yield.

The chemical weeding and application time before winter is after the 3-leaf stage of wheat, and the effect is the best when the weeds are almost complete and the tissue is delicate, generally from mid-November to early December, that is, about 40 days after wheat sowing. In order to ensure the control effect, the pesticide should be applied when the temperature is above 10 ℃ and the weather is fine and the soil moisture is good.

Combined with the production practice, we can choose to carry out in the clear and windless weather after irrigation or rain to ensure that there will be no rainfall 8-12 hours after application. If the temperature is lower than 6 ℃ and the soil is dry, it is difficult to exert the efficacy, which will affect the weeding effect.

What kind of herbicide should I choose?

Herbicides in wheat fields are selective chemicals. For the control of broad-leaved weeds such as pig seedlings, Artemisia annua and shepherd's purse, 10 grams of benzoolone per mu or 1 gram of 75% giant star, 40 kg of water can be evenly sprayed, and the control effect can reach more than 95%. For the control of grass weeds such as wild oats, Aegilops tauschii and Candellia ternata, the control effect can reach more than 85% with 6.9% Lima 40-50 ml or 3% Shima 20-25 ml per mu, mixed with 50-100 ml of the product additive and evenly sprayed with 40 kg of water.