Opportunities for biological weed control in Europe

The development and application of biological weed control offer great oppo rtunities not only for farmers, nature conservationists and other vegetatio n managers but also for institutions and companies that wish to sell plant protection services and products, and for the general public that demands s afe food and a visually attractive and diverse environment. Despite the obv ious opportunities for biological weed control, few control agents are actu ally being used in Europe. Potential agent organisms have features that mak e them particularly strong and useful for biological control, but they also have weaknesses. Weaknesses include a too narrow or too wide host specific ity, lack of virulence, or sensitivity to unfavourable environmental condit ions. Developing specific knowledge on the interaction between weeds and potentia l biological control agents, as well as expertise to increase the effect of control agents and so achieve sufficient weed control in a cost-effective manner, should have the highest priority in research programmes. From 1994 to 2000 most ongoing research on biological weed control in Europe was comb ined in a cooperative programme. This COST Action concentrated on the inter actions between five target crop weeds and their antagonists (pathogens and insects), on further characterisation of the specific blems and potential control agents and on the most suitable biological control approach. The next major challenge will be to apply the findings provided by COST-816 to the development of practical control solutions. The leading objective o f a new concerted research programme with European dimensions will be to st abilise or even promote biodiversity in the most important European ecosyst ems by integrating biological weed control in the management of these syste ms.