When is it proper to mix two herbicides?

The proper time to mix two herbicides is when their label directions indicate compatibility. This is crucial because the labels provide specific guidance based on extensive testing to ensure the products will not react adversely when combined. Compatibility can affect the effectiveness of weed control as well as minimize the potential for crop damage or environmental harm.

Choosing to mix herbicides based solely on their systemic nature, chemical class, or manufacturer does not guarantee the products will work well together. Systemic herbicides target plants differently, and mixing them without label guidance could lead to unexpected results. Similarly, even if herbicides belong to the same chemical class or are produced by the same manufacturer, these factors do not inherently ensure their compatibility or safety when mixed.

Therefore, always following label instructions is the best practice for maintaining efficacy and safety when using multiple herbicides.