Assessment of the Economic Impact of Sorghum Variety S 35 in ChadA MYapiauthorGDehalaauthorKNgawarauthorAIssakaauthorThe S 35 sorghum variety is a nonphotoperiod-sensitive, high-yielding, ear ly-matur ing, and drought - tolerant pure line that originated from ICRISAT' s breeding program in India, and was later advanced and promoted in Cameroon and Chad. Its int roduct ion into drought -prone areas of Chad has been very successful wi t h a net present value of research investments estimated at US$ 15 mi l l ion, representing an internal rate of return of 95%. Two crucial factors explain this apparent success: (1) germplasm research spillovers from ICRISAT and Cameroon's breeding programs substantially reduced the t ime lag in S 35 research and development in Chad; and (2) the FAO/UNDP-suppor ted seed project at Gassi not only successfully mul t ipl ied S 35 seed on a large scale, but also dist r ibuted it to farmers by adopt ing the 'mini-doses' approach and involving the Office national de developpement rural and NGOs . Since the recommended management practices for S 35 adopt ion are simple, relatively easy to implement wi t h available fami ly labor and animal t ract ion, and are not capital intensive, the technology has found favor wi t h many farmers. Between 1990 and 1995, the percentage of adopting farmers grew f rom 14% to 80%. In 1990, 7% of the total sorghum area (13 000 ha) was sown to the S 35 variety. By 1995, the area under S 35 had increased to 27% (66 000 ha). A yield advantage of about 5 1 % over farmers' local varieties is associated wi t h the adopt ion of S 35. The three major constraints cited by farmers - susceptibility of the variety to bi r d attack, the high cost of seed, and low soil fertility - should assist in the formulat ion of future research priorities.SorghumAgriculture-Farming, Production, Technology, Economics1999International Crops Research Institute for the Semi-Arid TropicsMonograph