Framework for an expert evaluation for the evolution of weed resistance

Abstract

The apparent rate of evolution of resistance of weeds to herbicides has increased substantially over the past decade. Data suggests phenotypic expression is affected by the mechanism of action of the herbicide, the taxonomy of the weed, the extent and frequency of selection and the agronomic context of herbicide use that contribute to the development of herbicide resistance. The opportunities for herbicide resistance are maximized in weeds that produce prolific seed, have relatively short half-life in the seedbank, and are obligate outcrossers; for herbicides that have a single target site that is not conserved or have multiple non-target resistance mechanisms; and in management, those management systems that do not use a diverse set of weed management tools and rely only on herbicides for weed control. The ability to identify weed and herbicide combinations that are most likely to develop herbicide resistance can aid in education and management systems to delay herbicide resistance.

Keywords

• herbicide resistance
• resistance management
• resistance index
• integrated weed management