Getting more for less with seed yam

Getting more for less with seed yam

At harvest, West African yam farmers keep up to 30% of their tubers to plant the next season, so many yams that could be sold or eaten must be saved as seed. A seed tuber can weigh over a kilogram, but it can be cut into minisetts: 30 to 90 gram pieces. If planted three weeks earlier than usual (with irrigation if necessary), minisetts can produce seed yams at a seed-to-crop ratio of 1:30, instead of 1:3. A hectare of yam planted with 30-gram minisetts yields almost as much as one planted with 90-gram pieces, while saving an additional ton or two of seed. However, farmers were wary of the smaller sizes. The most skeptical farmers were invited to participate in demonstrations, where the minisetts (treated with chemicals to prevent pests) produced good seed yam. The expected productivity increase for the adapted yam minisett technique is about 25%, and it should be promoted more widely.