No more wheat weedkiller after March 15th. Why?

As we know, the sensitive degree of wheat and weeds of herbicide is different, different period, also is different, in the process of wheat growth period, some times, weeds can resist the medicinal properties of herbicide, but the security of wheat will be affected, so must grasp the application period of wheat herbicides, correct to avoid causing phytotoxicity of wheat.

Why not apply the herbicide after the jointing period?Because: wheat in the jointing stage to the pregnant stage, is the reproductive growth and nutritional growth of wheat co-development period, this period is also the life of wheat most vulnerable, the most sensitive period, at this time of wheat drought resistance, waterlogging resistance, cold resistance, saline-alkali tolerance significantly weakened.

Spring wheat weeding, spraying herbicide use period should generally be before March 15.This period is very sensitive to herbicides, and even a slight carelessness will produce pesticide damage, which not only inhibits the growth of wheat, but also leads to the death of tillers and malformation of wheat ears, resulting in slow growth of wheat and serious non-spike or non-grain-grafting of wheat, causing uncontrollable influence on the final yield.

In addition, I would like to remind you that if the herbicide containing bensulfuron is used after the harvest, care should be taken in the later planting of soybeans, as herbicide residues may occur.

So, what are the precautions when spraying wheat herbicide?

1. Symptomatic application according to the type of weeds

Wheat crop herbicide may be hypertonic isoproteron.For older fields,

Wheat fields dominated by monocotyledonous weeds may be used with jinoxazole grass spirit;

In fields with more broad-leaved weeds, chlorofluoropyriloxyacetic acid cream or disinfectant spray can be added.

Under normal circumstances, in addition to wild oats, see mainiang, successively wheat, such as grass weeds, can choose shima (methyl disulfuron), maiji (pargyn), 6.9% horse and other agents stem and leaf spray;

In addition to sowing artemisia, shepherd's purse, quinoa, mother-in-law na and other dicotyledon weeds, can choose chlorofluoropiroxyacetic acid cream, dimethyl-tetrachlorosodium, difluorosurochloromethane and other agents.Use in strict accordance with the proportion of concentration and technical operation procedures, so as to avoid harm.In order to avoid adverse effects of herbicides on the next crop, chemical weeding in spring is prohibited to use mesulfuron, chlorsulfuron and other drugs with a long residual period.

2. It is better to apply medicine before jointing

Wheat is very sensitive to dimethyltetrachloride at seedling stage, and the resistance gradually increases after 3-4 leaf stage, and is strongest at the end of tillering stage, and then increases at the differentiation stage of young panicle. Therefore, it is generally required to apply the drug from 4 leaf stage to before jointing.

40% paraquat and 2, 4-d-butyl ester cannot be used after jointing of wheat, or they will easily cause harm to wheat. If used too late, they will lead to non-granulation of wheat.Pesticide applying wheat in the jointing stage to booting stage, then it is wheat vegetative growth and reproductive growth period, leading one of poor drug resistance and sensitive, easy to produce the adr, inhibit the growth of wheat, killing tillers, grain deformation, slow growing, so should be spray before elongating stage, such as wheat jointing-booting stage of Biao horses, four chloride, dimethyl herbicide dicamba and other sensitive, easy to cause the medicine came curling, confusing wheat yellow, growth inhibition, destroy the spike differentiation, cannot normal earing or ear deformity.

3. Select herbicide carefully according to the length of residual efficacy

The application of the herbicide containing bensulfuron in the spring wheat field is likely to cause damage to subsequent crops such as cotton seedlings and soybeans, so the herbicide should be applied before winter, and the interval between sowing and the next crop should not be less than 60 days, so as to ensure the safety of subsequent crops.

, CFC's are relatively overlooks oxygen ethanoic acid emulsifiable solution and almost out spirit for herbicides in wheat field control broadleaf weeds in wheat seeding of the security is higher, after jointing stage of wheat fertilization generally do not have much influence on wheat growth and development, and these herbicides in the field of residual period short, spring wheat field of crop after the medicine does not produce harmful effects.Bensulfuron and other herbicides have a relatively long residual effect period, and it is generally not suitable to apply after spring wheat jointing, so as to avoid pesticide damage to subsequent crops.

After the jointing of wheat, weed should be weeded out

Considering that the application of herbicide may have adverse effects on jointed wheat, the method of selective treatment can be adopted in the field application of herbicide, and the spraying is mainly applied to areas with excessive weeds. At the same time, it should be noted that the spraying should not be repeated blindly even in areas with excessive weeds to prevent adverse effects on wheat caused by excessive local dosage.