Excessive use of closed herbicides will exceed the tolerance of crops, leading to phytotoxicity, and even severe cases will still have residual effects in the future. Cause of injury: 1. Excessive use of blocked herbicides is an important factor of phytotoxicity, and both pretilachlor and butachlor have this problem. 2, improper medication can also lead to drug harm. For example, using pretilachlor requires that the seeds have buds and roots, and there can be no water in the field. After using pendimethalin, the soil should be covered.

First, block the consequences of excessive herbicides.

1, the consequences of overdose

Excessive use of closed herbicides will cause phytotoxicity, because it has exceeded the tolerance of crops, and because of excessive use, there will still be residual effects in the future. It is recommended to use herbicides according to the dosage recommended by the manufacturer or trademark.

2. Causes of plant poisoning

(1) dose

Excessive dosage of blocking herbicides is an important cause of phytotoxicity, and both pretilachlor and butachlor have such problems.

(2) Improper use

Pre-bud herbicides must be strictly managed. For example, when using pretilachlor, the seeds are required to have buds and roots, and there can be no water in the ground; The soil must be covered after using pendimethalin, otherwise there will be phytotoxicity.

(3) wrong medication

Generally, pretilachlor, butachlor and other drugs are used in rice fields, and herbicides need to be selected before germination according to farming methods. If the herbicide is used improperly, it will have serious consequences. For example, there has been a large area of herbicide damage in Jiangxi Province, mainly because the direct seeding rice fields do not use oxadiazon.

Second, when will the closed herbicide be ready?

1, spraying time

In order to give full play to the role of closed herbicides, it is necessary to let them penetrate into the soil in the germination area of weeds and kill them after germination. Therefore, closed herbicides are generally used after rain or in the morning with heavy dew, while general pesticides can be used in the morning or evening when the temperature is 10-24℃.

2. Preventive measures

(1) Avoid using drugs during the high temperature period at noon, because people are prone to heatstroke when they work in the sun for a long time, and pesticides are easy to volatilize and spread quickly after encountering high temperature. At this time, the concentration of drugs in the air will be higher than usual, increasing the risk of pesticide poisoning.

(2) It is not recommended to spray drugs in rainy days, because the combination of drugs and rainwater will be diluted twice, reducing the concentration of drugs, resulting in poor efficacy.