The role of ecology in the development of weed management systems: an outlook

This paper discusses the extent to which a knowledge of weed biology and ec ology can contribute to the development of weed management strategies. To d ate, such contributions have been modest and have been constrained by a num ber of factors that are discussed in this review. In contrast to other pest management disciplines, devising integrated weed management strategies tha t address a diversity of weed species with a diversity of life history trai ts is difficult. Because of this diversity, robust systems that require eco logical insight beyond that of individual species are needed. Although the contributions have been modest, research findings have helped to shape weed management strategies in a number of important ways. Approaches directed a t weed population management have revealed important insights into populati on equilibria, density-dependent mortality and life stages particularly imp ortant in regulating population size. Ecophysiological research has helped to guide the development of biologically effective herbicide dosage strateg ies, whereas mechanistic interplant competition modelling coupled with empi rical field studies have aided in the identification of weed-suppressive cr op phenotypes. Finally, much has been learned about the influence of contro l tactics and agronomic measures on the evolution of herbicide resistance a nd the development of integrated weed management strategies to address it. In this paper, examples are reviewed where research in ecology and biology has helped to shape the practice of integrated weed management. More import antly, characteristics of such research programmes are identified so that f uture efforts in the discipline will have a context in which the relevance of research questions and approaches can be considered.