A herbicide is a type of pesticide that is used to control or eliminate weeds and unwanted plants. Weeds can be a significant problem in agriculture, competing with crops for nutrients, water, and light, and reducing yields and quality.
Weeds are plants that have long adapted to local crops, cultivation, farming, climate, soil and other ecological and production conditions. They attack crops from different aspects, competing with crops for nutrients, water and light, spread diseases and pests, reduce crop yield and quality.
Therefore, it is necessary to choose efficient, fast and economic methods to control weeds. At present, people use biological, ecological, physical, mechanical and chemical methods to control weeds, especially herbicides to control weeds has become the most common way. Because using herbicides has greatly improved labor productivity through chemical weeding. It is an important guarantee for high and stable agricultural production.
After being absorbed by weeds roots and buds, herbicides act on specific sites and interfere with weeds physiological and biochemical metabolic reactions, resulting in weeds growth inhibition or death.
Now there are many different types of herbicides, but they are usually divided into two categories according to action characteristics: pre-emergence herbicides and post-emergence herbicides.
Pre-emergence herbicides are also called soil treatment herbicides, which can only be used before or during the emergence of weeds. If they are used after the emergence of weeds, they are basically ineffective for weeds.
Post-emergence herbicides is also called stem and leaf treatment herbicide, which are usually used in the vegetative growth period after the emergence of weeds, and are basically ineffective for weeds that have not yet germinated in the soil.