Some Comments on the Assessment of Joint Action in Herbicide Mixtures

Abstract

Methods of assessing and describing the joint action of materials as herbicides are reviewed, and the shortcomings of the terms synergism and antagonism are discussed. Some of the lack of agreement on their meaning and evaluation is attributed to failure to define or recognize appropriate models to represent absence of synergism (and antagonism). General analytical and graphical procedures are presented, and for two simple models, the additive-dose model (ADM) and the multiplicative-survival model (MSM), the dose-response curves and isobols are compared. Three examples from recent literature are reworked.