The following official WSSA definitions of “herbicide resistance” and “herbicide tolerance” were proposed by the Herbicide Resistant Plants Committee, accepted by the WSSA Terminology Committee, and approved the the WSSA Board of Directors at the 1998 WSSA winter Board meeting in Chicago, IL. The definitions for these terms are presented below and should be used where applicable in all future publications of the WSSA.

Herbicide resistance: “Herbicide resistance is the inherited ability of a plant to survive and reproduce following exposure to a dose of herbicide normally lethal to the wild type. In a plant, resistance may be naturally occurring or induced by such techniques as genetic engineering or selection of variants produced by tissue culture or mutagenesis.”

Herbicide tolerance: “Herbicide tolerance is the inherent ability of a species to survive and reproduce after herbicide treatment. This implies that there was no selection or genetic manipulation to make the plant tolerant; it is naturally tolerant.”

Source: Weed Technology Volume 12, Issue 4 (October-December) 1998. p. 789.