Main herbicides and their application methods in wheat field

Wheat is a densely planted crop, so it is difficult to weed mechanically. Chemical weeding has the advantages of high efficiency, low cost and reducing labor intensity, so it is very popular among farmers. However, the improper use of herbicides will also lead to some problems, such as poor weed control effect, drug damage and residual pollution of current and subsequent crops. Therefore, it is very important to master the application technology of herbicides. The types and application techniques of herbicides commonly used in wheat fields in China are introduced below.

2mai 4murd butyl ester

[common name in Chinese] 2mai 4muri D butyl ester

[chemical name] 2, 4-n-butyl dichlorophenoxy acetate

[functional characteristics] 2mai 4 murine D butyl ester is a phenoxy acetic acid hormone type selective herbicide. It has strong internal absorption and conductivity. It is mainly used for post-seedling stem and leaf treatment in wheat field. After spraying on the stem and leaf surface of weeds, the solution passed through the stratum corneum and plasma membrane, and finally transmitted to all parts of the plant. After the weeds were injured, the stems and leaves were twisted and deformed, and finally died. Generally, the broad-leaved weeds appeared abnormal curling symptoms 24 hours after treatment, and 7Mel died 15 days later. Due to the differences in external morphology, tissue structure and physiology among plants, they showed different resistance to 2mai 4murD. In general, dicotyledons have a slow rate of degradation of 2mai 4murD, so their resistance is weak and easy to suffer, while Gramineae plants can metabolize 2mai 4murD quickly and make it inactive. Therefore, the drug has a good selectivity between wheat and dicotyledonous weeds.

[preparation] the commonly used preparation is 72% bot 2min 4 murine D butyl EC.

[applied technology] 72% 2% 4murine D butyl EC was used in wheat fields to control broad-leaved weeds such as Artemisia annua, shepherd's purse, quinoa, Polygonum polygonum, Artemisia angustifolia, Ixeris angustifolia, Ixeris angustifolia, etc., but not to Gramineae weeds. Suitable application period and dosage: in the wheat green period, use 72% 2mae 4murine butyl ester EC 40ml / mu, add water 25m / m 30kg and spray evenly. (2) the dose of 4Mel D-butyl EC can be mixed with trimethoprim and bromobenzonitrile, and the dosage can be reduced by half to expand the herbicide spectrum.

[notes]

1. 2mai 4mi D butyl ester is highly volatile, and the droplets can drift far in the air, causing damage to sensitive plants. Dicotyledonous crops such as spinach, legumes, cotton, rape and sunflower, which grow at the same time with cereal crops, are very sensitive to it, which is one of the main causes of drug damage to broad-leaved crops in China. Therefore, the application of the drug should be carried out in windless or light weather, and the spray head of the sprayer had better wear a protective cover to prevent the droplets from drifting to the dicotyledonous crop field. What's more, it can not be used in wheat fields interplanted with sensitive crops.

2. Strictly control the period and dosage of pesticide application. Wheat is sensitive to butyl ester before 3 leaves and after jointing, and it is easy to cause drug damage to wheat when used at this time. The symptoms of drug injury did not appear until after the heading stage of wheat. The light wheat shows that the wheat ear is bent and not easy to pull out from the flag leaf during heading, showing the shape of "crane head". The heavy wheat ear showed abnormal performance and became a "square head" ear. Therefore, the drug should be applied after the 3-leaf stage of wheat to before jointing.

3. Instruments that are sub-packaged and sprayed with 2mai 4murine D butyl ester should be specially used to avoid "secondary pollution".

4. 2mai 4 Mel D butyl EC should not come into contact with acid and basic substances, so as not to reduce the efficacy caused by hydrolysis, and should not be stored with seeds and chemical fertilizers.

Dimethyl tetrachloride

[Chinese common name] 2 methyl 4 sodium chloride

[chemical name] 2-methyl-4-chlorophenoxy sodium acetate

[characteristics of action] the mode of action and selectivity are the same as those of 2pm 4murine D butyl ester. However, its volatility and action speed are lower and slower than those of 2mai 4murine D butyl EC.

[preparation] 20% 2-methyl-4-chloro-sodium salt and 56% 2-methyl-4-sodium chloride wettable powder

[applied technology] the herbicide spectrum of 2-methyl-4-chloro-sodium is basically the same as that of 2-methyl-4-chloro-sodium. Suitable application period: in the peak tillering stage of wheat, apply 20% 2 methyl 4 sodium chloride water 250 Mu 300 ml, add water 25 Mel 30 kg to spray the stems and leaves evenly. Matters needing attention are the same as those of 2pence 4murine D butyl ester.

Triticum aestivum

[Chinese common name] Maicaowei

[other name] Baicao enemy

3, 6-dichloro-2-methoxybenzoic acid

[characteristics] Triticum aestivum is a benzoin acid herbicide, which has the function of internal absorption and conduction. The drug is used for post-seedling spray and is quickly absorbed by the leaves, stems and roots of weeds and transmitted up and down through the phloem and xylem. The medicine is mostly concentrated in the meristem and the parts with strong metabolic activity, hindering the normal activity of plant hormones, thus causing its death. It has significant control effect on annual and perennial broad-leaved weeds. Generally, broad-leaved weeds will appear abnormal curl symptoms 24 hours after treatment, and 10 Mel will die 20 days later.

Wheat and other Gramineae plants can quickly metabolize and make it invalid after absorbing agents, so they show strong drug resistance.

[preparation] 48% Baicao antihydrant.

[applied technology] Triticum aestivum was used to control Artemisia annua, shepherd's purse, Chenopodium, pig calamity, cattle plume, big nest vegetable, buckwheat vine, Xanthium sibiricum, Scutellaria przewalskii, Bauhinia mandshurica, etc., but had no control effect on Gramineae weeds. Suitable application period and dosage: from tillering to jointing of wheat, use 48% Baicaoduo water agent 25ml / mu, add water 20ml / mu, spray evenly. In order to expand the herbicide spectrum, herbicide can be mixed with other herbicides with different herbicide spectrum. Like 2mae4Mel D, it is strictly forbidden to drift to the surrounding sensitive crops when applied. Wheat should not be applied before 3-leaf stage and after jointing stage, so as to avoid drug damage.

Bromobenzonitrile

[Chinese common name] bromobenzonitrile.

[other name] accompanying land farmers.

[chemical name] 3. 5-dibromo-4-hydroxy-1-cyanobenzene.

[functional characteristics] Bromobenzonitrile is a selective contact herbicide for post-seedling stem and leaf treatment. It is mainly absorbed by leaves and conducts extremely limited transmission in plants, which rapidly causes plant tissue necrosis by inhibiting various processes of photosynthesis. Within 24 hours of application, the leaves faded and necrotic spots appeared. Under the condition of high temperature and strong light, the death of leaves was accelerated.

[preparation] with 22.5% EC.

[applied technology] Bromobenzonitrile was used in wheat field to control Artemisia annua, Shepherd's purse, Chenopodium, Polygonum polygonum, Buckwheat vine, Buckwheat vine, Niu Xie, nesting vegetable and so on. It has no control effect on gramineous weeds. Suitable application period and dosage: in the 5-leaf stage of wheat, broad-leaved weeds are basically emerging in the vigorous growth period before the 4-leaf stage, 22.5% bromobenzonitrile EC is used in 100ml / mu, 25ml of water is added and 30kg is sprayed evenly. The drug can be mixed with 2-methyl-4-methyl-D-butyl ester or 2-methyl-4-chloro-sodium, etc., to expand the herbicide spectrum. The dose of mixed use was halved compared with that of each agent alone. The herbicide is a contact herbicide for stem and leaf treatment, and the application period should be as early as possible. When the weed plant is larger, the weeding effect decreases. In addition, if there is rain after application, it should be re-sprayed.