When will the herbicide after corn seedlings be effective and safe?

The suitable time to apply herbicide is after 6 pm, because the temperature is lower and humidity is higher, the solution will stay on the leaves of weeds for a long time, the weeds can fully absorb the herbicide components, which is beneficial to improve the weeding effect, and at the same time, it can improve the safety of corn seedlings, and it is not easy to cause phytotoxicity.

1. When to use herbicides after corn seedlings

1, because after spraying corn herbicide, it takes 2-6 hours to absorb the process, in these 2-6 hours, the effect of the effect is ideal, generally closely related to temperature and air humidity, in the morning of high temperature and dry weather, or noon and afternoon spray.

2, due to high temperature, strong light, rapid volatilization of liquid medicine, after spraying for a while the liquid medicine will evaporate, so that the amount of herbicide into the weed body is limited, will lead to insufficient absorption, thus affecting the weeding effect, at the same time in high temperature and drought spraying, corn seedlings are also prone to phytotoxicity.

3, the appropriate time for spraying is after 6 pm, because at this time spraying, the temperature is lower, the humidity is larger, the solution stays on the weed leaves for a long time, the weed can fully absorb the herbicide components, which is conducive to ensuring the weeding effect, and the evening application can also improve the safety of corn seedlings.

4. Because most of the herbicides after corn emergence are nicosulfuron, some corn varieties are sensitive to this component and prone to phytotoxicity, so corn fields planted with sweet corn, waxy corn, Denghai series and other varieties should not be sprayed to avoid phytotoxicity. For new varieties of corn, it is necessary to test first and then popularize.

2. How to use herbicides after corn emergence

1. Look at the size of grass

(1) When spraying herbicides after corn emergence, many farmers think that the smaller the weed, the less resistant it is, and the easier it is to kill the grass.

(2) Because the grass is too small, there is no pesticide area, and the weeding effect is not ideal. The better grass age is 2 leaves and 1 heart to 4 leaves and 1 heart. At this time, the weed has a certain pesticide area, and the weed resistance is not large, so the weeding effect is better.

2. Corn varieties

Because most of the herbicides after corn emergence are nicosulfuron, some corn varieties are sensitive to this component and easy to cause phytotoxicity, so it is impossible to spray corn fields planted with sweet corn, waxy corn, Denghai series and other varieties to avoid phytotoxicity. For new corn varieties, it is necessary to test first and then popularize.

3. Pesticide mixing problem

7 days before and after spraying herbicides, do not spray organophosphorus pesticides, otherwise it is easy to cause phytotoxicity, but can be mixed with pyrethroid pesticides, pay attention to avoid heart leaves as much as possible when spraying, avoid liquid irrigation heart.

4. Resistance of weeds themselves

In recent years, the stress resistance of weeds has improved. In order to avoid excessive evaporation of water in their bodies, weeds do not grow so strong, but grow gray and short. The actual grass age is not small. Most of these weeds are covered with white small hairs to reduce evaporation of water.