Indigenous knowledge and agro-morphological evaluation of the minor crop Kersting’s groundnut (Macrotyloma geocarpum (Harms) Maréchal et Baudet) cultivars of Benin

Kersting’s groundnut (Macrotyloma geocarpum) locally named “Doyi” is a grain legume of high nutritional and economic value widely consumed in Benin but neglected by the scientific research and the development programmes. In order to document the indigenous knowledge related to the production, diversity and use of this crop and to collect samples for characterisation and evaluation, 30 villages from South and Centre of Benin were randomly selected and surveyed. In each village, 10–15 producing households (374 farmers in total) were chosen as above and interviewed using participatory research appraisal tools and techniques. The study revealed that the production of Kersting’s groundnut is particularly concentrated in central Benin (departments of Zou and Collines), but is seriously declining for ten reasons. As reported by farmers, the most important factors of those included the high cost of production (40.7 % of responses), the susceptibility of cultivars to high soil moisture (25.5 % of responses) and the complexity of the cultural practices (25.2 % of responses). Only three local cultivars differing mostly by the colour of seed coat (white, red and black) were recorded. The white seeded cultivar was the most cultivated and preferred for consumption. Gender role analysis indicated that young women were the most involved in the cultivation of M. geocarpum. Phenotypical analysis of the different accessions (32 in total) collected during the study revealed only three groups that differ mainly in leaf width, yield and date to 50 % flowering. Agronomic evaluation indicated a significant difference (p < 0.05) between grain yields of the three local cultivars displaying a mean of 1062 ± 93, 1197 ± 77 and 1548 ± 102 kg/ha for the white, red and black seeded cultivars, respectively. The study also showed that Kersting’s groundnut is very soil selective. Results from the current study will contribute to define appropriate conservation strategies and also to implement adequate breeding programs. These will help to improve and promote local cultivars and the crop in Benin.