Tank mixes of two or more pesticides are commonly applied. Sometimes these pesticides may not mix well in the tank even though each product alone mixes well. Also, there are situations where it is desirable to use a fluid fertilizer or liquid nitrogen as the carrier. Some pesticides are compatible with fluid fertilizers and some are not. Every batch of fluid fertilizer or liquid nitrogen should be tested for compatibility.
Batches can vary in pH, salt concentration, or even temperature.
Minor differences may affect compatibility. The procedure for a compatibility test is often outlined on pesticide label. Follow these steps, in order, to perform a compatibility test. Add 1 pint of the fluid fertilizer to each quart jar. Gently shake for 5 to 10 seconds.