Diversity, genetic erosion and farmer’s preference of sorghum varieties (Sorghum bicolor (L.) Moench) in North-Eastern Benin

Abstract

Sorghum (Sorghum bicolor (L.) Moench) is an importance cereal crop which contributes 20 - 25% to food security and poverty alleviation in Benin. However, sorghum production is subject to various constraints. This paper aims to assess the varietal diversity, distribution and extent, the rate of diversity loss and farmers preferential criteria for adopting sorghum varieties in the North-eastern of Benin. Fifteen villages were randomly selected for the study and the data collected based on relevant questionnaire using the tools and methods of participatory research. The results showed maximum of 12 constraints in which climate change (76.34%) was rated by many farmers as the top most problem affecting the sorghum production. Based on vernacular names (local names) and subject to synonymy, medium diversity of sorghum (27 varieties) with a Shannon-Weaver diversity index (H) estimated at 2.46 bits was recorded. The number of varieties per village varied from 1 to 10 with an average of 4 varieties per village. The rate of varieties loss recorded per village varied from 0 to 100% (26.95% on average). At this rate of genetic erosion, local sorghum varieties might be vanished around 2030. There is an urgent need to conserve our valuable sorghum genetic resources through the establishment of National Genebank for Sorghum in Benin. The other reasons opined by the farmers for sorghum diversity loss are the varieties sensibility to poor soils, low productivity, bad quality of dough and tchoukoutou (local drink) and low market value. The most important sorghum varietal cultivation preferred by farmers’ are high productivity, good culinary quality (dough and porridge) and the high market value among the 12 identified criteria. Participatory evaluation showed that few tolerant or resistant varieties for poor soils and striga were recognized. This requires the implementation of a national program for sorghum improvement and breeding to identify high-performance varieties adapted to soil and climatic conditions