Dog days with frequent occurrence of diseases and insect pests: when is it appropriate to take medicine?

Dog days are the time when the summer temperature is the highest, and it is also the peak period of diseases and insect pests of all kinds of crops. Many farmers will choose to give medicine to crops, and the efficacy of most pesticides will often increase with the increase of temperature. So when is it most suitable to administer drugs?

When is the best time to take medicine in dog days?

1. Avoid the high temperature at noon

Some farmers will take advantage of the high temperature to administer medicine and feel that the high temperature is effective, but the actual situation is just the opposite. In the period of high temperature, pests will not come out, and the impact of medication on pests is often relatively small, coupled with the rapid volatilization of pesticides in the high temperature environment, which leads to poor efficacy.

Whether it is plants or insects or germs, 20-30 ℃, especially 25 ℃, is the most active temperature. At this time, medication is the most effective for diseases and insect pests and safer for crops. In the hot summer season, the medication time should be before 10:00 and after 4pm.

two。 Don't take drugs in the early morning.

The weather in dog days is very hot, many farmers will take advantage of the coolest time in the morning to take medicine, in fact, this effect is not very good. If the time is too early and the dew has not evaporated, the agent will be diluted by the dew on the plant, reducing the concentration of the agent, so that the effect of administration is not good.

When spraying in summer, spray in cloudy and sunny days from 8 am to 10:00 and from 5 pm to 7 pm, when the pest activity is exuberant. In order to prevent the occurrence of drug damage, the amount of water should be increased appropriately. When spraying, you must wear a good mask, wear long-sleeved protective clothing, and take a bath in time after spraying to prevent poisoning.

Common misunderstandings of medication in dog days

1. The concentration of dispensing is too high.

In the case of high temperature, the temperature of pesticides should not be too high. In the high temperature environment, the evaporation of water in the solution is relatively rapid, which is equivalent to increasing the concentration of the solution, and the crops are prone to drug damage, so farmers should mix the medicine strictly according to the spray concentration in summer, and should not increase the concentration privately.

two。 The sprinkler is too close.

After the liquid is ejected from the sprinkler, it collides with the air and breaks into smaller droplets, that is to say, within a certain distance, the farther away from the sprinkler, the smaller the droplets, and the droplets are easier to deposit and spread on the crops. so it is not that the sprinkler is close to the plant and the drug effect will be better.

Generally speaking, the spray head of the knapsack electric sprayer should be kept at a distance of 30cm to 50cm from the target, while the motorized sprayer should be kept at a distance of about 1 meter. According to the performance of the sprayer and the sprinkler, swinging the sprayer to let the spray fall on the crop will be more effective.

3. The smaller the droplets, the better the effect.

In fact, the spray droplets are not as small as possible. the size of the droplets is related to whether they can be better distributed, deposited and spread on crops. If the droplets are too small to float in the air and it is difficult to deposit on the target, this will certainly lead to waste. If the fog droplets are too big, the liquid falling on the ground will also increase, which is also a waste.

Suitable spraying instruments and nozzles should be selected according to the control objects and their space environment, and smoke machines can be selected when controlling diseases and small pests such as whitefly and aphids in relatively airtight sheds, and instruments and sprinklers with larger fog droplets should be chosen to control these diseases and insect pests in the open field.

In the hot weather in dog days, farmers need to pay attention to protective measures to avoid pesticide volatilization and floating on the skin, otherwise there may be poisoning.