Résumé
On the northern Mediterranean island of Corsica, 28 populations of subterranean clover were tested during 3 years: 18 French native ecotypes, and 5 Australian and 5 Spanish cultivars. A principal component analysis showed that dry matter yields, seasonal growth rhythms, and maturity date were the most important factors in the observed variability. By cluster analysis, 6 groups of subterranean clover were defined from these factors. Seasonal and total yields were linked to annual rainfall, but with a specific coefficient for each group. For 100 mm of rainfall, we obtained a range of production from 0.4 t DM/ha for the least productive group to 1.1 t DM/ha for the highest yielding group. The Australian cultivar, Clare, and 9 native Corsican ecotypes were the most productive genotypes (up to 10 t DM/ha.year in a wet year, with 2 t DM/ha during the winter period). These highest yielding ecotypes could be exploited to breed new mid-to-late-maturing cultivars better adapted to northern Mediterranean environments. In the short term, Clare may be used on large scale, for establishment of improved pastures in this region.