1, according to the temperature and its changing trend to determine the application time

Whether it is a plant or an insect or a pathogen, 20 to 30 ° C, especially 25 ° C, is its appropriate activity temperature. At this time, the medicine will be more effective for the disease and caterpillar grass in the active period and safer for the crop.

(1) In the summer high temperature season, the application time should be before 10 am and after 4 PM.

(2) In the spring and autumn cool season, it should be chosen after ten in the morning before two in the afternoon.

(3) Winter and spring greenhouses, choose the morning of warm weather to apply medicine.

2, according to the humidity and its change trend to determine the application time

After the liquid medicine sprayed from the nozzle is deposited on the target, it needs to be expanded to form a uniform film to cover the surface of the target to a large extent, and then "cover" the pests and diseases on the target. From deposition to development of liquid medicine, it is affected by many factors, among which the influence of air humidity is greater.

(1) The air humidity is small, the water in the drops will quickly evaporate into the air, and even the liquid medicine can not be spread on the target, which will of course reduce the efficacy, and even appear burning drug damage spots.

(2) The air humidity is too large, the liquid medicine deposited on the surface of the plant, especially the large fog drops, is easy to condense into larger droplets, and the lower part of the plant is affected by gravity twice, which will also produce drug damage.

Therefore, the application time of the day needs to follow two principles, one is that the air humidity is slightly dry, and the other is that the liquid after the application can form a dry film on the surface of the target before sunset.

Two, three common illusions

1, only according to the dilution ratio to determine the number of agents per barrel of water

Most people are used to calculating how much medicine to add to each barrel of water according to the dilution factor, which is not very reliable. The reason to control and calculate how much medicine to add to the medicine cabinet is to calculate how much medicine per unit area of the plant needs, in order to have good efficacy, and safety for the plant and the environment.

Special reminder: After adding many agents in each barrel of water according to the dilution ratio, it is also necessary to calculate the details such as how many barrels of water are needed per mu of land and the speed of spraying.

At present, due to the constraints of the labor force, many people tend to add quantities of medicine to the liquid medicine tank and spray it quickly, and this approach is obviously wrong. The reasonable measure is to choose a spraying machine with better spray performance, or to apply the medicine according to the product instructions and spray carefully.

2. The closer the nozzle is to the target, the better the effect will be

When the liquid comes out of the nozzle, it collides with the air and breaks into smaller droplets as it rushes forward, stumbling along the way as the droplets get smaller and smaller. That is to say, within a certain distance, the farther away from the nozzle, the smaller the droplets. Small droplets are more likely to deposit and spread on the target. So, it's not that the spray head against the plant works better.

In general, the head of the knap-type electric sprayer should be kept at a distance of 30 to 50 centimeters from the target, and the motor sprayer should be kept at a distance of about 1 meter. According to the performance of the sprayer and its nozzle, the swinging nozzle should let the spray fall on the target, and the efficacy will be better.

3, the smaller the droplet, the better the effect will be

The smaller the droplet, the better. The droplet size is related to its better distribution, deposition and spread on the target. If the droplets are too small, they will float in the air and will not settle on the target, which will certainly cause waste; If the droplets are too large, the amount of liquid medicine falling on the ground will also increase, which is also a waste.

Therefore, according to the control object and its spatial environment to choose the appropriate spraying machinery and sprinkler, in the relatively closed shed to control diseases and white whitefly, aphids and other small pests can choose the smoke machine, in the open field to control these pests and diseases have to choose the spray machine and sprinkler droplets larger, the smoke machine is obviously not suitable.