Improving staple crops in their centers of diversity tends to be a particular challenge for plant breeders. Sorghum in West Africa is such a case, where plant breeders struggle to contribute new varieties that combine superior yields with traits necessary for good adaptation and end-use or marketing, and thus add new and useful varietal diversity.
ICRISAT's sorghum breeders in West Africa introgressed 10-20% of exotic germplasm into local guinea race sorghums. Through careful selection for reduced plant height and good adaptation, breeding lines of a novel plant type were identified. Results indicated that the shorter stem-internodes of this material had significantly higher stover digestibility and stems were completely consumed, whereas the woody stems of traditional sorghum varieties are typically left uneaten by ruminants. These new dual-purpose varieties can therefore be used as roughage for feeding livestock as well as grain for human consumption.
To test whether these new lines have the much sought after improved grain yield, ICRISAT and the Institut d'économie rurale (IER) Mali Sorghum Program, local farmer organizations, and extension services organized farmer managed performance trials in 8-10 villages. Each farmer grew two replications of the trial with 16 entries, including his own control variety and a common researcher control. Technicians assisted farmers with the field layout and sowing. Farmers managed the trial as an adjacent field. Researchers evaluated the trials twice during the cropping season, and conducted the harvest with all other partners. Threshing was done under researcher supervision. Farmers and visitors from the villages evaluated the varieties throughout the growing cycle, and until after the threshing.
Analyzing the grain yields across locations confirmed that these new short-internode variety types indeed combined higher grain yield with improved stover quality. Two varieties, Kalaban from IER and ICRISAT's Nafalen 6, produced 25% higher grain yields on average across the whole spectrum of growing conditions sampled in this multi-location test (Figure1).
Farmers' initial assessments of these new varieties were not so positive as the panicles did not appear heavy, drooping less than traditional varieties with some grain discoloration from late rains. However, the yield figures were so convincing that farmers continue to work with us to improve the grain color. These varieties are now listed in the Malian National Variety Catalogue and farmer organizations have started marketing the seeds.