On-farm varietal biodiversity was studied through household surveys in two high potential production systems in Chitwan and Nawalparasi districts of the Nepal Terai and in Lunawada sub-district, Gujarat, India. Diversity was extremely low in Chaite rice in the Nepal study area (weighted diversity 0.04) and low in main season rice in the India study area (weighted diversity 0.34). In both areas, one cultivar dominated, CH 45 in Nepal and GR11 in India. In the India study area, biodiversity varied with the socio-economic group and better-off farmers had a greater varietal diversity. Participatory varietal selection (PVS) identified new varieties that farmers preferred. Their adoption by farmers increased on-farm varietal biodiversity within the three cropping seasons studied. Despite the commonly assumed uniformity of high potential production systems, the new varieties occupied specific niches in the farming system. Farmers' preferences for different varieties – there were large differences in quality traits and maturity period among the new varieties – should help to maintain biodiversity. Overall production is expected to increase as each niche becomes occupied increasingly by the best-adapted variety. PVS is a simple and powerful method of increasing food production in the high potential production systems that produce most of the developing world's grain.
Witcombe, J.R.; Joshi, K.D.; Rana, R.B.; Virk, D.S. Increasing genetic diversity by participatory varietal selection in high potential production systems in Nepal and India. Euphytica (2001) 122 (3) 575-588. [DOI: 10.1023/A:1017599307498]