Which of the following factors contributes to the development of herbicide resistance?

Overreliance on a single herbicide is a significant factor that contributes to the development of herbicide resistance. When a specific herbicide is used repeatedly over time, the target weed species are exposed continually to that herbicide, which allows for the selection of resistant individuals. Those resistant plants survive and reproduce, leading to a population that is increasingly difficult to control with that herbicide.

In contrast, practices like regular rotation of crops help to disrupt the cycle of weed resistance because they typically involve using different herbicides or herbicide modes of action. This diversity in herbicide application can reduce the pressure on any single weed population to develop resistance. Increased rainfall during the growing season and proper application techniques, while relevant to overall crop health and management, do not directly lead to the evolution of herbicide-resistant weeds in the same manner that overreliance does. The focus on a singular herbicide application creates a situation where resistance is more likely to develop, highlighting why it is crucial to incorporate integrated weed management strategies to mitigate this risk.