This information herein was originally prepared as briefing material for the midterm technical review of the CIMMYT/United Nations Development Programme (UNDP) project IIResearch on the Development of New, Stress-Resistant Maize Genetic Resourcesll (GLO/90/003/A101/42) in September, 1993. The CIMMYT Maize Program undertook this project in 1990 in response to concern about the stability and sustainability of developing world maize production. In particular, it was noted that average annual growth in maize yields in developing countries had slackened from 3.0% during the 1970s to 1.7% in the 80s, whereas maize utilization had risen at an average annual rate of nearly 4.0% over 1961-90, and would continue to grow at that pace or even more quickly up through the year 2000. To help meet this demand, the Program set out to generate maize germplasm thatwould possess genetic resistance to major constraints of developing world production environments--insect pests, drought, low nitrogen conditions, and acid soils. Corollary aims included the more efficient use of natural resources, particularly in marginal zones, and a reduction in the application of potentially harmful chemicals. The project was designed to benefit farmers by providing improved, resistant "source" germplasm to national agricultural research programs and others who develop and disseminate improved maize technology. The expert panel commissioned by UNDP to review the project at midterm found that the Maize Program's research had met and, in many cases, exceeded th~ technical benchmarks established. This report describes the activities, methodologies, germplasm, and data developed and tested under the project. We encourage you to contact the scientists responsible or the Maize Program Director's office to request seed or further information related to this work.