Why might using lower herbicide rates in harder water be a concern?

Using lower herbicide rates in harder water is a concern primarily because they may not be as effective. Hard water contains higher concentrations of minerals such as calcium and magnesium, which can bind with certain herbicides, reducing their availability for uptake by target plants. This binding can lead to decreased efficacy of the herbicide, as the chemical may not reach or affect the plants as intended.

In scenarios where control of specific aquatic vegetation is critical, using reduced rates can result in insufficient herbicide action, allowing the unwanted plants to persist and potentially grow more robustly. Therefore, when managing aquatic environments, it’s essential to consider both the hardness of the water and the appropriate herbicide application rates to ensure effective pest control.