2001, Volume 9, Paper 4

ISSN: 1883-5675

Herbicide Resistance and the Decision to Conserve the Herbicide Resource: Review and Framework

Rick S. Llewellyna, Robert K. Lindner, David J. Pannell & Stephen B. Powles

Abstract

The demonstrated ability of major cropping weeds to evolve resistance to most major herbicides threatens the sustainability of herbicide-dependent weed management systems. In Australia, the rapidly increasing herbicide resistance problem now presents a need to reassess herbicide use as a resource management problem. Although resistance to some herbicides is already widespread, most grain growers have several herbicide options still available to control weed infestations in crops. These growers are being encouraged to adopt practices that place less reliance on herbicides to delay, if not prevent, the emergence of further herbicide resistance. It is argued that this requires a form of resource conservation decision, the resource being herbicide susceptibility. To maximise the net present value of returns, growers need to select the optimal use of herbicide susceptibility and the more costly alternative practices over time. This paper integrates concepts of resource economics and the literature on the adoption of innovations to contribute to a framework for weed management decisions where herbicide resistance is developing. Implications for achieving rapid and high level adoption of integrated weed management practices by growers are discussed, given the requirement for perceived profitability in a complex adoption context where high uncertainty is present.

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