Coevolution of agricultural systems and their weed companions:: implications for research

Weed management opportunities can be found in responses such as seed germination, development of canopy architecture, flowering, and seed production and dispersal. However, there are still research challenges to be addressed before prediction of crop and weed phenology can be reliably used in weed management strategies. In this paper we will focus on those ecological processes where we believe research efforts hold the greatest promise for the use of phenology prediction: succession, evolution, and interference. Research challenges for new management strategies are finding ways to forecast future weed populations in response to environmental changes, and to engineer crop cultivars capable of producing the desired environmental changes and responses to biotic and abiotic interactions. (C) 2000 Elsevier Science B.V. All rights reserved.