What does tolerance mean in relation to herbicides?

In the context of herbicides, tolerance refers to a plant's inherent ability to withstand and recover from exposure to herbicides without significant injury or death. This means that a tolerant plant possesses physiological or biochemical traits that enable it to either degrade the herbicide more effectively or to mitigate the herbicide's effects on its growth and development. Such traits allow the plant to survive and continue to thrive despite the application of herbicides that would normally be harmful to other, more susceptible plants.

This concept is critical in agriculture and horticulture, as using tolerant varieties can lead to more effective weed management while minimizing damage to desirable crops. Understanding tolerance helps in selecting appropriate herbicides and application strategies that will target unwanted plants without harming beneficial species.

In contrast, resistance generally refers to a plant's ability to evolve and adapt over time to survive herbicide applications, which differs from inherent tolerance that exists within plant varieties initially. Hence, tolerance focuses on immediate plant response to herbicide exposure, while resistance involves a longer-term evolutionary process.