BEAN PROGRAM; ANNUAL REPORT, 1979

This report details that work, which also included an agroclimatology study, hybridization and progeny evaluation, evaluation and improvement of agronomic practices, validation of technology in on-farm trials, and other studies relating to temperature adaptation, growth habit stability, and seedling vigor. A total of 10,000 germplasm accessions were inoculated and evaluated under screenhouse and field conditions at CIAT and in Popayan. A modification in the screening methodology -- inoculating and evaluating (progeny test) individual F or advanced selections under greenhouse conditions rather than field inoculation of F2 families -- considerably increased screening efficiency. Tests were made for resistance/tolerance to viral disease, fungal and bacterial diseases, insects, moderately acid soils, and water stress. All improved lines are now resistant to BCMV. Lines resistant to multiple diseases and pests have been entered in the international yield trials. Significant differences in disease and insect pest incidence were confirmed in maize-bean associations as compared to monocultures. Farm trials were carried in Huila, Colombia with monoculture bush beans, in the Restrepo region with monoculture bush beans, and in Antioquia with climbing beans in relay systems with maize. Materials in the 1979 IBYAN (International Bean Yield and Adaptation Nursery) were still deficient in meeting consumer acceptability, but have high agronomic value. Attention was also directed to developing tolerance to production constraints such as drought, low phosphorus availability in the soil, and biological N2 fixation. Improved biological N2 fixation under higher temperatures was achieved. In addition, efforts were made to strengthen the research and technology transfer network in Latin America by selecting trainees from the region, organizing meetings and workshops, distributing germplasm, and collaborating with country programs.