Applying post-emergence herbicide to corn and then re-spraying after rain does great harm to the crops

If it rains right after applying herbicide to corn, the efficacy of the sprayed herbicide may be weakened, but how much it is weakened also depends on the timing of the spraying and application. Most current herbicides are basically systemic herbicides, and the absorption time is very short; after 2-3 hours, the sprayed herbicide can be mostly absorbed. In that case, spraying the herbicide again will instead cause herbicide damage.

Herbicides must not be abused. Even if the product label states that the effect is low-toxicity, as the saying goes, every medicine is three parts poison. In the case of repeated spraying of pesticide herbicide, it may also cause herbicide damage to the corn, and in severe cases may even cause death.

If it rains after the herbicide is sprayed, the herbicide sprayed on the leaf surface will also flow into the soil. Some netizens may ask whether the herbicide that enters the soil can still be effective, and this has to be discounted. Although the herbicide is a systemic herbicide, among the portion of the chemical that flows into the soil with the rainwater, if the roots can come into contact with it, it can still be absorbed, but the part the roots have not yet reached cannot exert its efficacy. In that case, how much can ultimately be utilized is a question mark.

For now, do not rush to spray pesticide again. You can hold off a bit, wait and see, and keep observing. If you see that the weeds in the field have died and the effect is pretty good, then do not spray herbicide again. Of course, if the weeds in the field are completely unaffected, then it will not be too late to consider spraying herbicide at that time.

After all, the herbicide also needs some time to take effect. If the efficacy is still good after the rain, generally in about a week the broadleaf weeds and grassy weeds in the field will gradually turn yellow and die. But if you do not see them turning yellow, then consider the question of spraying again.

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