ABSTRACT
Bliss developed the first statistical models of joint action of pesticide mixtures based on three theoretical modes of physiological interaction. These types of interaction are independent joint action, similar joint action, and synergistic action. For practical purposes, the simplest hypothesis of pesticide interaction that can be tested experimentally is that of independent, uncorrelated, joint action. This hypothesis means that the effect of one component of the pesticide mixture is not correlated with the effect of the other and is applicable to data from experiments with mixtures consisting of pesticides of different chemical types. Synergism is the occurrence of significantly greater mortality than predicted by the model, and antagonism is the occurrence of significantly reduced mortality: Another simple, easily tested hypothesis that can be examined is similar (or additive) joint action. The effects of synergists are most sensibly modeled by deriving a dose–response model based on a particular biological mode of action.
