It is about to enter the critical period of spring farming and farming . The timely use of pesticides can not only save pesticides and reduce costs, but also improve the control effect, reduce drug residues, effectively control the damage of pests and diseases, and ensure the normal growth of crops. So when is the pesticide applied well? How is the pesticide application time determined?
When is the pesticide applied well?
The period of pests: For pests, the period of pest growth can be the period of egg hatching, the period of larvae, and the period of adult growth. After all, the effect of drug control is most obvious, depending on the specific situation. In principle, it is necessary to control the living habits of pests, and it is carried out at the stage where the most harmful insects are easily killed and can effectively control the damage.
For example, the control of armyworms , spraying at the peak of egg hatching, although the effect of hatching larvae is good, but not necessarily effective for late hatching larvae, and when the larvae 2-3 age peak, spraying drugs, one control It can solve the pest problem. For example, when controlling cotton bollworm, the newly hatched larvae should be drilled into the bud bell in a short period of time. If the larvae are used at the peak of 2-3 years old, the control effect is very poor, and the medicine is used at the peak of the egg hatching period. The control effect is particularly remarkable; rice aphids and Spodoptera litura are also the same.
How to determine the pesticide application time
When controlling pests, it should usually be used before the peak period of larvae 2-3 years old, and some should be controlled after the peak period of egg hatching. At this time, the application can get twice the result with half the effort. The main causes are:
First, the resistance to young age is weak : the younger pests are thin at the 3rd instar body, and there are many hairy hairs on the body wall. The epidermis of the micro hairy part is very thin, and the medicine is easy to pass through. One layer, and at this time, the worm is small, the food is small, the damage is light, the activity field is small, and the resistance to drugs (drug resistance) is weak. Therefore, the appropriate period for controlling pests should be controlled before the peak of 2-3 years. Some should be controlled before and after the peak period of egg hatching, which can achieve the best control effect.
When the pests reach 4-6 years old, the food intake and body wall thickness of the pests are greatly increased, and the thickness can reach 50-100 times of the 1st instar larvae, and the micro hairs on the body wall are also absent, so that the agent is not easy to adhere. In the body wall and through the body wall, it is more difficult to reach the body of the pest, and at the same time, the resistance (resistance) of the pest is also greatly increased, thereby greatly affecting the insecticidal effect of the medicament. And after the age of the pest increases, the amount of fat in the insect body also increases, and it has the function of backlogging and decomposing many pesticides. The higher the body fat content of the pest, the more obvious this effect is, and the stronger the resistance (resistance).
Second, the sensitive period of natural enemies : During the period when the natural enemies of the pests are sensitive to the chemical reaction, the medicine should be used as little as possible or not, so as to protect the natural enemies and maintain the ecological balance in the field.
The third is the disease-producing period : for the disease, the growth period of susceptible disease is the best period of chemical control. If the seedling stage is most susceptible to bacterial blight, it can be mixed with fungicides before planting or sprayed at the seedling stage; and the flowering period is also the peak period of disease infection. Therefore, it is necessary to control the focus of the drug during the flowering period. Prevention and control, control the occurrence and spread of diseases.
The fourth is the sensitive period of weeds : the application of herbicides should usually be controlled during the sensitive period of weeds. For weeds that are seed-grown, the herbicides are more sensitive to herbicides during the shoot and seedling stages. Therefore, this period is often the time for herbicides. Usually control is good after sowing seedlings or weeds 1-2 leaves. When using broad-spectrum herbicides, such as gram-free, glyphosate, and nutrient, it should be used when the weeds are flourishing during the growing season. The herbicidal effect is obvious and the long-lasting effect is long. If weeds are used to control weeds in spring and summer, it is best to spray herbicides at the beginning of weeds.
The fifth is the fasting period of the rodent: from the effective section of the rodent control, the release of the poisonous cockroach should be better in the rodent fasting stage. Years of experiments have confirmed that the best effect of rodent control in spring is because the winter storage of the rodent is depleted, and the feeding of poisonous cockroaches is more corresponding. At the same time, the rodent in spring can also reduce the cardinal number and protect the normal emergence and safe growth of spring-sown crops. .
Sixth, the plant safety period : the safety of the pesticide to the plant is a prerequisite for judging the application period. When applying pesticides, it is necessary to select the period during which the crop has strong resistance to the medicament, so as not to cause crop phytotoxicity.
Seventh is the safety interval : the application period of pesticides should also be based on the safe use standards of pesticides , and the control should be applied during the safety interval to avoid excessive pesticide residues, resulting in undesirable results.
More pesticide knowledge , please pay attention to China Pesticide Network
Article source: Tianbao Agricultural Technology Service Platform (ID: zhxdnyjs)
Guanghan Longrun Science and Trade Technology Trade Co., Ltd. , https://www.kairungongju.com