Herbicide Resistance in Weeds: Evolution, Mechanisms and Agronomic Mitigation Strategies

Abstract

One of the most serious threats to global crop productivity and sustainable weed management in present scenario is herbicide resistance. Dependency on repeated application of herbicides with similar modes of action, simple cropping systems and reduced diversity among agronomic practices turns out to be major reason for evolution of resistant weed populations across different agroecosystems. Currently, around 260 weed species have been reported to be resistant to one or more site of action, leading to increased yield losses, production cost and environmental concerns. Resistant weed populations usually evolve through different mechanisms such as target-site resistance, which mainly occurs due to genetic mutations at the specific herbicide binding site, and non-target-site resistance, which includes different mechanisms like enhanced herbicide metabolism, reduced translocation or sequestration. To delay or avoid the development of herbicide resistance and restore sustainability we have to implement agronomic mitigation strategies which include crop diversification, cultural and mechanical interventions, use of integrated weed management practices (combination of chemical, cultural, mechanical and biological methods) and precise use and application of herbicides Globally, herbicide resistance has started to become a wide spread problem in controlling the weeds. Studies have reported that resistant weed species can easily cause around 20–70% yield losses, depending on the crop, weed species and infestation level. To delay or avoid the development of herbicide resistance and restore sustainability we have to implement agronomic mitigation strategies which include crop diversification, cultural and mechanical interventions, use of integrated weed management practices and precise use and application of herbicides. It proper and timely solution of this problem is not developed or left unchecked than it can cause uncontrolled losses to crop yield.