How narrowly adapted are the products of decentralised breeding? The spread of rice varieties from a participatory plant breeding programme in Nepal

Acceptable rice varieties for high-altitude areas of Nepal were bred by participatory plant breeding (PPB). One of the most adopted varieties, Machhapuchhre-3 (M-3), performed much better in the formal trials system than the products from centralised breeding and was released in 1996. From 1996 to 1999, the spread of M-3 was monitored in high-altitude villages along with unreleased variety Machhapuchhre-9 (M-9), derived from the same cross. The study was done by interviewing individual households, groups, and field verification. Both M-3 and M-9 spread from farmer-to-farmer and through interventions by Non-Government Organisations (NGOs) and Government Organisations (GOs). Their adoption had steadily increased and their spread commenced five to six years earlier than would have been the case in a conventional system. The PPB programme was decentralised – all selection was in only two villages in the same valley – but this did not result in specific adaptation. The varieties were adopted in distant villages situated at much lower altitudes to the original PPB sites and the greatest yield advantage of the varieties over the local landraces was also at these lower altitudes. This revised version was published online in August 2006 with corrections to the Cover Date.