How does rain affect herbicide activity?

Rain typically influences herbicide activity in significant ways, especially in the timing and method of application. In this case, rain can wash herbicides off the leaves before they have a chance to be absorbed by the plant. When herbicides are applied to foliage, their effectiveness relies on being absorbed by the target plant. If rain occurs shortly after application, it may create a situation where the herbicide does not penetrate the leaf surface effectively before it is rinsed away.

This loss can result in reduced efficacy, leading to suboptimal control of the desired weed species. Understanding this mechanism is critical for applicators to determine the right timing for herbicide application to ensure maximum absorption and effectiveness.