Box 2-7. Integrated Pest Management.

There are many diverse definitions and interpretations of Integrated Pest Management (IPM). The internationally accepted FAO definition is "the careful consideration of a number of pest control techniques that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and safe for human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption of agroecosystems, thereby encouraging natural pest control mechanisms" (FAO, 2002b, 2005b). Additional endorsement of the revised Code is reflected in the European Commission's recent decision to include it in the forthcoming revision of the EU pesticides authorization directive 91/414, and to use it as the basis for proposing mandatory IPM for EU farmers by 2014.

     Contrasting interpretations of IPM have emerged over the period, each with different emphases./p>

• Toolbox IPM combines two or more tactics from an array of tools and is utilized primarily to optimize crop productivity (OTA, 1979; Cate and Hinkle, 1994). IPM is presented as a continuum of practices, with choices ranging from reliance mainly on prophylactic controls and pesticides to more biologically-intensive methods (USDA, 1993). The approach emphasizes a diversity of technical options, rather than the integration of multiple tactics under a broader ecological framework and does not necessarily require monitoring or conservation of natural enemies (Ehler and Bottrell, 2000; Ehler, 2006; Gray and Steffey, 2007).
• Pesticide-based IPM focuses primarily on the discriminate use of pesticides and improving the efficacy of pesticide applications (Ehler, 2006). The approach emphasizes pest monitoring and the use of less hazardous, lower dose and more selective pesticides, improved formulations, new application technologies, and resistance management strategies (CropLife, 2003; Syngenta, 2006). Some pesticide industry IPM programs may also feature use of the manufacturers' chemical products (Sagenmuller, 1999; Dollacker, 2000). Nonchemical approaches such as biocontrol are mentioned in some industry publications, but presented as "generally too often unreliable or not efficient enough to be commercially used on their own" (CropLife, 2003).

• Biointensive IPM, also sometimes described as Preventative IPM (Pedigo, 1989, 1992; Higley and Pedigo 1993) and Ecological Pest Management (Altieri, 1987; Altieri and Nicholls, 2004), emphasize the ecological relationships among species in the agroecosystem (Shennan et al., 2005) and the availability of options to redesign the landscape and ecosystem to support natural controls (Dufour, 2001). Biological and ecological pest management offer robust possibilities to significantly and sustainably reduce pesticide use without affecting production (van Lenteren, 1992; Badgley et al., 2007; Scialabba, 2007). Implementation remains limited globally as it often requires structural changes in production systems (Lewis et al., 1997) and redirection of market, research, policy and institutional support to favor ecosystem-oriented approaches.
• Indigenous pest management, based on detailed Indigenous technical knowledge (ethnoscience) of pest ecology, local biodiversity and traditional management practices, focuses on achieving moderate to high productivity using local resources and skills, while conserving the natural resource base (Altieri, 1993). Weeds, insect pests and crop pathogens are at times tolerated and provide important foods, medicines, ceremonial materials and soil improvers (Bye, 1981; Chacon and Gliessman, 1982; Brown and Marten, 1986). Control methods rely on a wide range of cultural, biological, physical and mechanical practices, water and germplasm management and manipulation of crop diversity (Altieri and Letourneau, 1982; Matteson et al., 1984; Altieri, 1985) and are supported by knowledge of the local agroecosystem and surroundings (Atteh, 1984; Richards, 1985). In Africa, farmers traditionally practice intercropping with various crops, which can drastically reduce pest densities, especially if the associated crop is a non-host of the target pest species (Khan et al., 1997; Schulthess et al., 2004; Chabi-Olaye et al., 2005; Wale et al., 2006), although farmers are not always aware of the beneficial effect that mixed cropping has on pest infestations (Nwanze and Mueller, 1989). Partnerships between formally trained scientists and farmers skilled in ethnoscience show promise for strengthening agroecological approaches (Altieri, 1993).