Which factor can contribute to herbicide control failure related to weather?

Excessive rainfall can significantly impact the effectiveness of herbicides. When heavy rain occurs shortly after herbicide application, it can lead to several potential issues. One concern is that the rain can wash the herbicide off the treated areas, reducing the amount of active ingredient that remains on the target weeds. This wash-off diminishes its ability to control the unwanted vegetation.

Another problem associated with excessive rainfall is the dilution of the herbicide, which can reduce its concentration in the areas it was applied, impacting its effectiveness. Additionally, heavy rains can create conditions that promote weed resurgence or seed germination, especially if the rain promotes soil disturbance. All these scenarios can contribute to herbicide control failure, making weather conditions, especially rainfall, a crucial factor in the successful application and efficacy of herbicides in turfgrass management.