Strategies of cereal rust management : redesign of an agro-ecosystem to alter its stability properties

• Main Author: Fleming, Richard Arthur
• Language: English
• Published: 2010
• Subjects: Cereals; Plant Diseases > epidemiology; Rust fungi
• Online Access: http://hdl.handle.net/2429/23446

A major concern in contemporary ecology has been the failure of management in many economically and socially important renewable resource systems. In spite of efforts to the contrary, management has often witnessed the evolution of such systems into behavior patterns almost diametrically opposed to their original objectives. Actually, it is management intervention which often seems to have initiated this evolution by disturbing the system's stability properties. This study shows how an alternative approach which emphasizes system redesign may alleviate the .problem of changing stability properties in some relatively simple and well studied ecosystems: the cereal rusts and the crops which they attack. The plant disease epidemiological literature records a number, of ideas about the behavior and management of cereal rust systems. Many of these ideas have been neither adequately field tested nor developed in a coherent analytic framework. In this study mathematical methods are used to determine the logical consequences of some of these hypotheses. The analysis suggests that cereal rust systems might indeed be redesigned to help management meet its objectives. Four alternative and mutually compatible potential strategies for achieving this goal are considered: (1) using natural enemies to delay disease onset, (2) using multilines or variety mixtures to inhibit plant to plant dispersal, (3) changing field geometry to increase dispersal wastage, and (4) employing polygenic resistance to slow the growth rate of the best adapted races. The research and development required to implement any of these strategies is briefly discussed. Recommendations for future work and comments on the promise of plant epidemiology as an area for ecological research are provided. === Science, Faculty of === Zoology, Department of === Graduate