IMPECCA: an international, collaborative program to investigate the development of a mycoherbicide for use against water hyacinth in Africa.

The IMPECCA Programme has been established to develop a mycoherbicide for the control of water hyacinth, using fungal isolates that have been found in Africa. Such a mycoherbicide could replace the use of broadspectrum herbicides, which are used routinely at present, but have caused concerns about contamination to fish and degradation of water quality. In addition, a mycoherbicide might be more compatible with the use of insect biological control agents. The project will build upon existing studies of formulating water hyacinth fungi into mycoherbicides which have been carried out in Egypt and Zimbabwe, and expertise gained by CABI Bioscience during the development and commercialisation of mycoinsecticides. One of the key outputs will be the strengthening of technical capacity and linkages within African national programs to undertake biological control of weeds. Scientists will carry out extensive exploration for pathogens of water hyacinth already present in Africa. These will be identified, characterised and assessed for suitability as the basis for a mycoherbicide; these studies will include molecular and chemotaxonomic identification of both fungal isolates and water hyacinth biotypes. Characteristics of a fungus isolate suitable for mycoherbicide development include: high pathogenicity, acceptable host specificity, low mammalian toxicity, and capacity for mass production and formulation. Candidate products will be laboratory and field tested for efficacy and compatibility with other (especially biological) control options. A water hyacinth management strategy will be proposed appropriate for local needs. WATER hyacinth is perhaps the most pernicious aquatic weed in the world. Water hyacinth is generally the dominant plant when it occurs outside of its native range and is capable of suppressing or eliminating other species. It forms dense mats of vegetation in lakes and dams, and irrigation and flood channels, where it impedes boat traffic, increases eutrophication and harbours the mosquito vectors of malaria, encephalitis and filariasis (Forno and Wright 1981). The problems are most severe in developing countries, where human activities and livelihoods are closely linked to the water systems. Conventional methods of control rely mainly on mechanical/manual removal and chemical herbicides, which have generally been found to be inadequate and expensive measures to apply on a large scale. Herbicides have the added dis1. The International Mycoherbicide Programme for Eichhornia crassipes Control in Africa (the IMPECCA programme) is funded by Danida (Danish International Development Assistance) through the Environment, Peace and Stability Facility. This article contains the views of the author, which do not necessarily correspond to the views of Danida. * CABI Bioscience, Silwood Park, Ascot, Berks, SL5 7TA, UK. Presented by Dr Bateman on behalf of program staff.