Herbicide Resistance: Definition and Management Strategies
A herbicide ceases to be a useful tool for farmers when its target weeds develop resistance to its effects. This publication helps you understand resistance: what causes it, and how you can slow or prevent its development.
Herbicide resistance is the inherited ability of a plant ot survive and reproduce following exposure to a dose of herbicide that would normally be lethal to the wild type. In a plant, resistance may occur naturally due to selection or it may be induced through such techniques as genetic engineering. Resistance may occur in plants as the result of random and infrequent mutations; there has been no evidence to date that demonstrates herbicide-induced mutations. Through selection, where the herbicide is the selection presure, susceptible plants are killed while herbicide-resistant plants survive to reproduce without competition from susceptible plants. If the herbicide is continually used, resistant plants succesfully reproduce and become dominant in the population. The appearance of herbicide resistance in a population is an example of rapid weed evolution.