Herbicide Mode of Action
Herbicides are chemicals that inhibit or interrupt normal plant growth and development. They are widely used in agriculture, industry, and urban areas for weed management. Herbicides can provide cost-effective weed control while minimizing labor. However, improper herbicide use may result in crop injury, poor weed control, herbicide resistant weeds, environmental contamination, or health risks. Herbicide mode of action refers to how herbicides work. Understanding how herbicides work provides insight into how to use the chemicals and helps diagnose performance problems and related injury symptoms.
Herbicides kill plants in different ways. A herbicide must meet several requirements to be effective. It must come in contact with the target weed, be absorbed by the weed, move to the site of action in the weed, and accumulate sufficient levels at the site of action to kill or suppress the target plant. Weed control is unsatisfactory unless these requirements are met.
All herbicide interactions with a plant, from application to final effect, are considered the mode of action. The herbicide mode of action involves absorption into the plant, translocation or movement in the plant, metabolism of the herbicide, and the physiological plant response. Herbicide site of action refers to the specific process in the plant that the herbicide disrupts to interfere with plant growth and development. The term “herbicide mode of action” is sometimes used interchangeably with “herbicide site of action.”