The composition of farmland weed community is diverse. Mixing herbicides can increase the spectrum of killing grass, reduce the dosage and reduce the production cost. Reasonable mixing can reduce pesticide residues and improve the safety of crops. After reasonable mixing, it can be extended or shortened. During the efficacy period, the application period can be flexibly adjusted. However, the mixing of herbicides is principled and the excellent combination of mixing should be selected or determined according to the circumstances.
When herbicides are mixed, it is necessary to understand the herbicidal spectrum of each herbicide, crop resistance, climate, the effect of soil on herbicide activity, the site of plant absorption of the agent and the conduction and metabolism in the body, the condition of the herbicide in the soil and Use the principle, etc., and then come up with an effective combination of pairs in order to receive the expected results. Generally, the following principles should be followed: 1. After mixing herbicides with different herbicide spectrums, it is necessary to expand the range of weeding and improve the control effect. Most of the herbicides currently used are selective, and the herbicides with different herbicidal spectrums are used in combination, and the mechanism of action should be complementary to each other, and more types of weeds can be prevented. For example, acetochlor can be used in combination with atrazine or selezin to significantly increase the range of weeding; weeding in rice fields can be combined with diquat and butachlor to prevent annual weeds and sedges. Perennial weeds, used before or after rice transplanting. When mixed with glyphosate, it can not only control the malignant weeds, but also the herbicidal effect of glyphosate. There are many weeds in the ramie field. The simazine is used alone. The herbicidal spectrum is too narrow. If it is mixed with dimethyltetrachloride, it can be used in 50-60 grams of simazine, mixed with dimethyltetrachloride, sprayed with 50 kilograms of water. Castor is applied before emergence, and it has a good effect on controlling gramineous and broadleaf weeds. Mixed herbicides must have different herbicidal spectrums, but the crops, age, and method of use must match.
2. Extend the duration of weeding and reduce the number of medications. When using herbicides, the herbicides with long-lasting effect and short-lasting period should be mixed and used to complement each other, not only to prevent weeds in the early stage, but also to basically control the grass damage during the whole growth period of the crop. . For example, in the paddy field, 10% rice grass-free wettable powder can be used for early treatment after bud pre-emergence, which can prevent annual and perennial broadleaf weeds and sedge; if mixed with butachlor, the herbicidal effect can be improved and can be achieved. Once in a single dose, the rice field has no grass for the whole season. For many years, wheat fields have mainly used herbicides such as 2,4-D and dimethyltetrachloride, which have led to the damage of grass weeds and resistant broad-leaved weeds such as camphor, coiled stalks, etc., while 2,4-D Herbicide-based drugs have a relatively short period of time. In order to overcome the above shortcomings, the combination of dicamba and 2,4-D is promoted, which not only expands the herbicidal spectrum, but also prolongs the application period, and can be extended to 1~3 of wheat crops. The period of the festival. In production, cotton field uses 25% diuron + 50% cable 150g per acre, the effect is better than 250g for single cable; Fluorine + cable + oxacillin 50g each, control peanut land Annual grass weeds and some broad-leaved weeds have better effects than 150 grams of trifluralin alone, and have a long-lasting effect. When mixing, use herbicides with different herbicidal principles as much as possible to improve the herbicidal effect.
3. Reduce phytotoxicity and improve safety. After the herbicide is properly mixed, the residual toxicity is smaller than that of the single use, and the safety of the crop is improved. The amount of mixed herbicide used is usually less than half of the single dose, which avoids the toxicity of the herbicide to certain crops. According to the experiment, bentazon is used alone for 50 grams per acre. It is used before the branching of piglets in winter, and the control effect on weeds such as piglet and Maijiagong can reach more than 95%; 40 grams per mu, the control effect on the first two weeds is only 46% and 65%; and 30 grams of bentazon per acre plus 20 grams of dimethyltetrachloride, the control effect is more than 95%, after mixing Wheat malformed spikes decreased by 3.2% compared to metformin alone. Some herbicides have long residual effects and can affect the lower crops. For example, they can be mixed with short-lived and low-toxic herbicides to avoid phytotoxicity and reduce the impact on the crops. For example, if the green merlon is more than 300 grams, it is easy to produce phytotoxicity, and it is very unsafe for the glutinous rice. However, the halving of chloroplast is mixed with chlorpyrifos, which not only protects the wheat field from phytotoxicity, but also facilitates squatting rice. Safety. For example, most of the weeds in the cornfield can prevent corn from being safe, but it is safe for corn, but it has residual phytotoxicity to various crops other than sorghum corn. If mixed with acetochlor, the herbicidal effect can reach about 95%. Moreover, the safety of the squat crop is greatly improved, and no phytotoxicity occurs. Practice has shown that if high doses of atrazine are used for many years, weeds such as valerian and crabgrass will become resistant to atrazine. The herbicidal effect of atrazine is significantly reduced. After being mixed, the resistance can be delayed and the pressure to form resistance can be reduced.
4. Improve the weeding effect. The herbicides have obvious synergistic effects after reasonable mixing. For example, the mixture of chlorpyrifos (metolachlor + strontium) has the herbicidal action of amides and substituted urea herbicides, the effect is improved, the herbicidal spectrum is enlarged, and most of the 1-year-old monocotyledonous and broad-leaved weeds can be prevented. . Dimethyltetrachloride is mixed with diuron, chlorpyrifos, chlorpyrifos, and granitic. According to the herbicide mixed herbicidal spectrum test observation: the use of chlorpyrifos alone is not effective for small squid, but if it is mixed with 10 grams of chlorpyrifos and 30 grams of dimethyltetrachloride per acre, the control effect on small squid is better. Good; diquat is used alone, and the effect on Ze paint and big nest is poor, but if it is mixed with 7.5 grams of diuron per mu and 30 grams of metformin, it is highly effective against Ze paint. Good control effect; the enemy is used alone, it is not effective for big nest vegetables, lacquer, leeks, sown worm, mustard, ion grass, etc., but 30 grams of enemy cockroaches are mixed with dimethyl tetrachloride per acre. Weeds are highly efficient; metformin is used in combination with chlorpyrifos and granules, and can be used to remove broad-leaved weeds such as rice stalks and squash. Wheat is a 15% acetyl oxalic acid wettable powder, suitable for controlling a variety of grass weeds in wheat fields; fast-killing, Pentium, etc. is suitable for controlling broad-leaved weeds and sedges in wheat fields, and the combination can effectively prevent wheat fields Most grass weeds, broadleaf weeds, etc. In addition, Maiji and Kuailing are not strict with the temperature conditions when applying the drug, and have good herbicidal effect during the low temperature period. The combination of Maiji and Kuailing or Pentium is safe for wheat, the herbicidal spectrum is enlarged, and the herbicidal effect is good. It is an excellent compound combination.
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