Beware of herbicide damage in wheat fields

In recent years, the use of herbicides in wheat has been increasing year by year, and phytotoxicity has occurred frequently. It must be prevented from the following aspects.

1. Selecting high-quality herbicides Herbicides in the market currently have many brands and their quality is uneven. Domestic herbicides were dominated by tribenuron-methyl before 2006. In recent years, compound formulations and combination products have developed rapidly, and foreign herbicides have been developed rapidly. The most well-known herbicides are Dow Corning, Bayer, Syngenta, DuPont, and FMC. In selecting herbicides, we must first eliminate the use of herbicides that have an impact on post-planting crops. Second, we must select herbicides that are produced by brand names and well-known large companies.

2. The correct use of the drug preparation must adopt the double dilution method: first add a small amount of water into the mother liquor, then pour it into a sprayer containing a certain amount of water, then add the amount of water to be added, add it while stirring, and mix thoroughly and dilute to the need. concentration. Do not pour medicine into water first, so that the medicine can be easily deposited at the suction pipe of the sprayer, so that the concentration of the liquid to be sprayed first is high, and it is easy to produce phytotoxicity. The concentration of the liquid after spraying is low, and the weeding effect is poor. It is also not allowed to pour the medicine into the sprayer containing a lot of water, so that the WP tends to float on the water meter or form a small piece, and the distribution is not uniform, which can not only ensure the effect but also easily clog the spray hole during spraying. The liquid must be prepared with clean water. The amount of water sprayed by the soil treatment herbicide should be higher, 667 square meters of water 50-60 kilograms, the conventional spraying of herbicides on stems and leaves may be less appropriate, and 667 square meters of water The amount is generally 30 to 45 kg, appropriate to increase the amount of water when there is insufficient moisture, and not to apply pesticides when there is lack of crops; the soil with high organic matter content is fine, the amount of herbicide adsorption is large, and the amount of soil microorganisms is large, activity Exuberant, drug dosage is degraded, can increase the amount of medication, sand loam coarse, the adsorption of the small amount of pesticide molecules in the soil particles are mostly free, strong activity, prone to phytotoxicity, the amount of drug can be reduced appropriately. When using the hand pressure sprayer, it is necessary to retreat or spray the medicine sideways. Do not spray on the side while walking. The speed of hand sprayer, the speed of walking and the height of the sprayer should be basically the same; the width of each spray should be the same. Spray should be carefully and evenly to avoid re-spraying or leaking; choose sunny and windless weather when spraying, prevent the liquid from drifting to nearby crops, and form pesticides on the surface of the soil after applying herbicides. Do not cultivate the pesticide within 1 to 2 weeks, so as not to damage the drug layer and reduce the weeding effect. Herbicides are best used with special sprayers. If no special equipment is used, all parts of the liquid must be soaked with quicklime or lime sulfur for more than 48 hours after spraying. Rinse with clean water before spraying the other crops. In addition, the mixture of herbicides must be selected according to the characteristics of herbicides, the characteristics of weed occurrence, and the fertility stage of crops, so as to avoid the blind use of herbicides.

3. Remedial measures (1) Spray water. When it is clear that the spraying dose of herbicide is too large, it shall be sprayed with clear water in time to remove the residual leaf, reduce the concentration of herbicide in the crop, and promptly irrigate the water to promote the transpiration of wheat and reduce the injury. (2) Strengthen fertilizer and water management. When the phytotoxicity is relatively light, brown spots appear in some leaves of the crop, and the heart leaves do not die. The losses of some leaves can be compensated by strengthening the management of fertilizer and water, and generally can be recovered in a short time. (3) Spray antidote or corresponding remedy. Ferrous sulphate can reduce the phytotoxicity of wheat without trace, and calcium polysulphate can eliminate the residual simazine activity in soil. Due to the phytotoxicity caused by auxin type herbicides, gibberellin can be sprayed to reduce the harm of the phytotoxicity; due to the phytotoxicity caused by the contact herbicides, foliar fertilizers can be sprayed to promote the rapid recovery of the crops, thereby relatively reducing the phytotoxicity.