The herbicide takes effect a few hours before it rains after corn seedlings.

Generally, it doesn't matter if the herbicide doesn't rain for a day, because the efficacy of the herbicide has already begun to play a role, but if it rains that day, it will affect the efficacy of the herbicide.

Corn (scientific name: Zea mays), also known as maize, corn and corncob. Cantonese is called Xiaomi and Minnan is called Fanmai. It is an annual gramineous herb, an important food crop and an important feed source, and also the highest total output food crop in the world.

Corn belongs to the genus Zea in Gramineae, and its scientific name is Zea. Corn, commonly known as cob, corn and corn, originated in Mexico and Peru along the Andes in Latin America. After Columbus discovered America, he brought corn to Spain on his second return trip (1499). With the development of the world navigation industry, corn has gradually spread to all parts of the world and become one of the most important food crops. Corn is known as longevity food, which is rich in protein, fat, vitamins, trace elements, cellulose and polysaccharides, and has great potential to develop foods with high nutrition and high biological function.

Herbicide is a kind of chemical that can completely or selectively kill weeds, also known as herbicide, which is used to eliminate or inhibit plant growth. Among them, sodium chlorate, borax, arsenate and trichloroacetic acid have lethal effects on any plant, and their effects are affected by herbicides, plants and environmental conditions. According to their functions, they can be divided into two categories: killing herbicides and selective herbicides. Most selective herbicides, especially derivatives of nitrophenol, chlorophenol and carbamic acid, are effective. The development of herbicides in the world is gradually stable, mainly developing varieties with high efficiency, low toxicity, broad spectrum and low dosage, and disposable treatment agents with little environmental pollution are gradually becoming the mainstream.

Commonly used varieties are organic compounds, which can be widely used to control weeds, miscellaneous irrigation, miscellaneous trees and other harmful plants in farmland, orchards, flower nurseries, grasslands and non-arable land, railway lines, rivers, reservoirs, warehouses and other places.