Maize pest management - multiple insect and disease resistant varieties are the key to success.

Integrated pest management (IPM) was conceived, first implemented, and refined as a holistic, more efficient and effective approach to managing pest populations and reducing damage/losses in developed countries. This was primarily as a means of reducing the environmental impact of traditional control measures. This approach has been successful for many crops and pests in developed countries, where the impetus to develop and refine such programs has been backed with the information and resources needed to make IPM functional. In contrast most developing countries agriculture and economies are different in scale, quality and complexity. The scientific knowledge and infrastructure, as well as the will or desire to change systems often lags far behind the developed countries. IPM has had little or no adoption or success in developing countries. By tailoring programs to the needs and realities of many developing countries and fully exploiting the potential of host plant resistance (HPR) and other appropriate and affordable components, IPM has a chance of being successful if properly planned and implemented. The major component of such programs, the key to success, would be availability of crop varieties and hybrids with adequate levels of HPR and good agronomic qualities and performance. HPR is fully compatible with other IPM components and technologies and can be complemented in certain environments in developing countries by appropriate use of these related technologies. Emphasis in the CIMMYT maize HPR program was switched in the late 1980's from single to multiple insect species and generations. The application of appropriate breeding and selection procedures in a disciplinary team approach has resulted in the development of materials that are now available for further testing, verification and eventual utilization in developing countries. Maize with resistance to the following combinations of pests is now available: Multiple borer and armyworm, multiple insects and leaf blights, multiple insects and streak, multiple insects and stunt, multiple insects and downy mildew. Selection and improvement for HPR to single species/generations is being continued for the following pests: second generation borers and armyworms, corn earworms, spider mites, maize weevil, larger grain borer, corn rootworms, ear rots and stalk rots. Once resistance levels are adequate in these materials, they can serve as sources for developing multiple trait resistant materials in whatever combinations are needed to combat the major biotic stresses that limit maize production on a global basis.