How should you handle incompatibilities when tank-mixing pesticides?

• A. Always mix everything regardless of compatibility
• B. Do not rinse equipment after mixing
• C. Avoid mixing incompatible products; perform a jar test if uncertain; consult label for compatibility; flush system if incompatibility occurs
• D. Use higher concentrations to overcome incompatibility

Answer: (C)

When mixing pesticides in a tank, you must guard against incompatibilities so the spray stays stable and effective. The best practice is to avoid combining products that don’t work well together; if you’re unsure, do a jar test to see how the mixture behaves before putting it in the tank. A jar test involves mixing a small amount of the proposed products with water in a clear jar and observing for signs like separation, precipitation, cloudiness, gel formation, or excessive foaming. If any incompatibility shows up, don’t proceed with the full tank mix. Instead, consult the product labels or contact the manufacturers for compatibility guidance, and flush and rinse the equipment if incompatibility occurs to prevent residue from interfering with future applications. Using higher concentrations to force compatibility is unsafe and can damage the crop, equipment, or yourself.