Abstract
Starting with the release of Rayong 3 in Thailand in 1984, the CIAT-related cassava cultivars officially released by Asian national programs now total to twenty four. Besides these, there are a far greater number of clones pre-released and left to the farmers' adoption without official naming. In the early years, clones previously selected at CIAT tended to become officially released cultivars of national programs, but recently more cultivars are locally selected from the crosses made locally or at CIAT using local and CIAT cross parents. The countries of origin for the parentage of those cultivars include more than ten countries, mostly Latin American, testifying to the functioning of an international breeding network. Rayong 3, Rayong 60 and Adira 4 in Indonesia are estimated to be planted now in more than 50, 000 ha each and the total acreage planted with all these improved cultivars is estimated to have surpassed 300, 000 ha. The additional economic effects (harvested roots on farms alone) generated by the adoption of new cassava cultevars in Thailand, Indonesia, China and the Philippines in the years upto 1993 are estimated at 128 millon US dollars. This far outweighs the estimated cost of the CIAT cassavaa breeding program and the cassava breeding programs in these four countries in the past 20 years (11.3 and 5.5 millon US dollars respectively) . Through this process, the breeding programs in Thailand, China, Indonesia, Vietnam, Philippines and Malaysia have gained momentum. I conclude that, even with this largely neglected crop cassava, we are fulfilling the most important role of the international agricultue research organization (CGIAR), i. e., the improvement and utilization of crop germplasm in collaboration with national programs.
