Herbicide and Adjuvant Tank Mix Compatibility Testing in Oklahoma Roadside Vegetation Management Programs.

Many herbicide labels recommend pesticide applicators conduct a standard jar test for herbicide and adjuvant tank mix compatibility before mixing products on a large scale. An industry standard jar test helps to locate physical tank mix incompatibilities in advance of large scale mixing and loading. The Oklahoma Department of Transportation (ODOT) requires physical tank mix compatibility testing for herbicides and adjuvants before these products are placed on an approved herbicide and adjuvant purchase and use list. This poster will summarize the findings of herbicide and adjuvant tank mix testing for physical compatibility conducted by the Oklahoma State University roadside vegetation management program on behalf of ODOT during the 1994 -1995 and 2004-2011 time period. During the 1994 and 1995 tests some 27 herbicide and adjuvant tank mixes were found to have physical incompatibility problems. By 1995 changes in formulations had dramatically reduced findings of physical incompatibility. During 2004 - 2009 no physical incompatibilities were found. During 2010 and 2011 only one set of combinations was found to have physical incompatibility problems. The industry standard jar test remains a simply and inexpensive means of locating physical tank mix incompatibility before large scale mixing and loading of pesticides and adjuvants occurs in the field.