Impact of Germplasm Research Spillovers: The Case of Sorghum Variety S 35 in Cameroon and ChadA MYapiauthorS KDebrahauthorGDehalaauthorCNjomahaauthorAn important objective of international agricultural research inst i tut ions is to determine the extent to which research under taken in one location may impact on other regions of interest. Thi s is because research activities are most often planned to target mandate crops and agroecological areas found in many parts of the world. ICRI S A T has, as a pol icy, disributed a wide range of parental materials to breeding programs in the NARS and private seed industries throughout the semi-arid tropics. This has cont r ibuted to faster and cost-effective development of useful final products by the receiving parties. Thi s study evaluates the impacts and research spillover effects of adopt ion of sorghum variety S 35, a pure line developed f rom the ICRI S A T breeding program in India. It was later advanced in Niger ia and promoted and released in Cameroon in 1986 and Chad in 1989. Today, S 35 occupies about 33% of the total rainfed sorghum area in Cameroon and 2 7 % in Chad. Compared to farmers' best t radi t ional varieties across all study sites in Cameroon and Chad, S 35 yields 2 7 % more output (grain) and reduces uni t product ion cost by 20%.These farm-level impacts are larger in Chad where yield gain is 5 1 % higher and cost reduct ion is 3 3% higher. Th e net present value of benefits f rom S 35 research spillover in the Af r ican region was estimated to be US$ 15 mi l l ion in Chad and US$ 4.6 mi l l ion in Cameroon, representing internal rates of return of 9 5% in Chad and 7 5% in Cameroon. These impacts were evaluated f rom the perspective of nat ional research systems. A conscious decision, therefore, was made to include only those costs associated wi t h nat ional research and extension inst i tut ions. Al l other S 35-related research and development expenditures incur red in India and Niger ia were treated as 'sunk costs', that is, costs which woul d have occur red anyway wi thout spillover. Ha d each count ry had to develop S 35 and associated management practices on its own, the t ime lag between research and release of the technology woul d have been longer and consequently impacts, if any, woul d have been smaller. For greater effectiveness in sorghum technology development and transfer in the region, future research and pol icy actions should take greater advantage of research spillovers through more col laborat ion, communicat ion, and networking between nat ional , regional , and internat ional research inst i tut ions.SorghumAgriculture-Farming, Production, Technology, Economics1999International Crops Research Institute for the Semi-Arid TropicsMonograph