The Eco-Evolutionary Imperative: Revisiting Weed Management in the Midst of an Herbicide Resistance Crisis

Abstract

Abstract:Modern weed science is at a crossroads. Born out of advances in chemistry, it has focused on minimizing weed competition with genetically uniform crops and heavy reliance on herbicides. Paradoxically, the success obtained with such an approach and the reluctance to conduct integrated and multidisciplinary research has resulted in unintended, but predictable, consequences, including the selection of herbicide resistant biotypes. Advances in eco-evolutionary biology, a relatively recent discipline that seeks to understand how local population dynamics arise from phenotypic variation resulting from natural selection, habitat distribution, and propagule dispersal across the landscape are transforming our understanding of the processes that regulate agroecosystems. Within this framework, complementary tactics to develop alternative weed management programs include the following: (1) weed scientists must recognize that evolution occurs within crop fields at ecologically-relevant time scales and is rooted in the inherent variation that exists in all populations; (2) weed management should recognize that the probability of a resistant mutant is directly related to the population size; (3) farmers need to acknowledge that herbicide resistance transcends any one farm and should coordinate local practices with regional actions; (4) incentives should be developed and implemented to help the adoption of eco-evolutionary management programs; and (5) risk analysis can help incorporate an eco-evolutionary perspective into integrated weed management programs.

From one species to another: A review on the interaction between chemistry and microbiology in relation to cleaning in the built environment

“…59,60 A non-exhaustive summary is provided in Table 1. In the same way that agriculture is embracing a "many little hammers" approach 62 in weeds by using a combination of control methods, so, too, antimicrobial resistance can be delayed or thwarted by combining multiple strategies for cleaning, disinfection, and sterilization. 61 Therefore, effective cleaning in settings containing significant amounts of carbohydrates, fats, proteins, or other organic materials may benefit from antimicrobial activity coupled with removal or disambiguation of organic materials, that is, "soil."…”

An ecological perspective on managing weeds during the great selection for herbicide resistance

“…This network of connected factors can include positive as well as negative feedback loops that may accelerate or inhibit changes to weed population dynamics. Thus, an important research goal for weed science in the coming decades is to learn how to create cropping systems that exert shifting, unpredictable selection pressures, disrupting rather than exacerbating the evolution of problematic weed traits . Applying a diversified, but spatiotemporally invariant, suite of weed management tactics is insufficient to prevent any one weed species complex from getting too comfortable.…”

Herbicide resistance evolution can be tamed by diversity in irrigated Australian cotton: a multi‐species, multi‐herbicide modelling approach

“…For every n new seeds that are produced of a given species, a new, mutant plant is added, with an identical genotype to one other randomly selected individual plus the addition of an allele or gene for one randomly selected resistance trait. In the current implementation, default n = 1 × 10, but this parameter can be varied readily.…”

“…In highly effective herbicide‐based systems it is reasonable to suspect that very few weeds ever die from anything other than the herbicide(s) used in the system. In evolutionary terms, then, there is tremendous selection pressure towards resisting the herbicide(s) applied . The system is, in effect, pushing the weed community in a particular evolutionary direction – and the result is no surprise to students of herbicide resistance or farmers in any industrialized cropping system.…”

“…In evolutionary terms, then, there is tremendous selection pressure towards resisting the herbicide(s) applied. 8 The system is, in effect, pushing the weed community in a particular evolutionary direction 9 -and the result is no surprise to students of herbicide resistance or farmers in any industrialized cropping system. If increasing the diversity of weed management tactics decreases the frequency with which individual weeds are killed by any particular tactic, theoretically optimal diversity could be thought of as a point at which the weed community is under minimal (or ideally no) net pressure to move towards resistance to any one particular tactic over long (i.e.…”