ABSTRACT
This chapter considers simultaneous exposure of plants to multiple herbicides, as well as other agrichemicals, to be the same phenomenon whether the multiple exposure is the intentional result of the application of a mixture of agrichemicals or from sequential application of the chemicals. It focuses on the interactions between herbicides in mixtures with other herbicides, safeners, insecticides, fungicides, and nematicides. Many of the advantages of using an herbicide in mixture with other herbicides also apply to use of mixtures of herbicides with other agrichemicals. Interactions between herbicides and other agrichemicals are possible in the spray solution, on or within the plant, and in the soil. The simplest approach to categorizing the joint action of two biologically active chemicals on a test organism, such as two herbicides together on a plant, defines the interaction as antagonistic, additive, or synergistic. Conceptually, it is easier to analyze the results of mixing a nonherbicide with a herbicide than for when two herbicides are mixed.
