Novel chemical approaches to crop protection: Needs and solutions

The examination of conventional chemical methods of crop protection suggests problems and opportunities that call for alternative approaches. The need for such novel treatments is considered in relation to damaging organisms not controlled by traditional pesticides, biological availability, resistance, selectivity and compatibility with other methods within the concept of integrated pest, disease or weed management. Analysis of these needs and opportunities suggests directions in which to seek novel chemical agents including those which can attack vital processes not previously exploited as target sites, the modification of physicochemical properties determining mobility and availability, chemical formulation, symptom suppression and the manipulation of chemically-mediated processes other than direct toxic action, and the use of agents which extend the usefulness of existing toxic agents. Examples illustrating these approaches are discussed.