What does the continuous use of the same herbicide class result in?

The continuous use of the same herbicide class can lead to a higher likelihood of resistance in target plant species. When a specific herbicide is used repeatedly, the plants that are susceptible to that herbicide are eliminated, while those that have or develop resistance survive and reproduce. Over time, this selective pressure increases the overall proportion of resistant individuals in the population. As a result, the efficacy of the herbicide decreases, making it more challenging to control the weed species in the future.

Resistance management strategies often involve rotating herbicides from different classes with varying modes of action. This practice reduces the chances of resistant individuals dominating the population, helping maintain the herbicide’s effectiveness in controlling unwanted aquatic vegetation.