Jar Testing

Jar Testing For Compatability


  1. Add 1 pint (.50 L)  of the carrier (water or liquid fertilizer) to each of two one-quart (1.0L) jars. (Note: Use the same source of water that will be used for the tank mix and conduct the test at the same temperature the spray mixture will be applied.)
  2. To one of the jars, add 0.25 teaspoon (1.0 ml) of the compatibility agent. To both jars, add the appropriate amount of pesticide(s), in their relative proportions, based on recommended label rates. If more than one pesticide is used, add them separately with dry formulations first, flowables next, and emulsifiable concentrates last. After each addition, shake or stir gently to thoroughly mix.
  3. When all ingredients are added, put lids on and shake both jars for fifteen (15) seconds and let stand for thirty (30) minutes or more. Then inspect the mixture for flakes, sludge, gels, heavy oil films, or other signs of incompatibility.
    • If, after standing for thirty (30) minutes, the components in the jar containing no compatibility agent are dispersed, the herbicides are compatible and no compatibility agent is needed.
    • If the components are dispersed only in the jar containing the compatibility agent, the herbicide is compatible only if a compatibility agent is added.
    • If either mixture separates but can be remixed readily, the mixture can be sprayed as long as good agitation is used.

If the components are not dispersed or show signs of incompatibility in either jar, the herbicide-carrier mixture is not compatible and should not be used.