Multilocational agronomic evaluation of selected Centrosema pubescens germplasm on acid soils

Twenty-three accessions of Centrosema pubescens selected for good performance on an infertile, acid soil were tested along with 2 control lines each of C. pubescens and C. acutifolium at 18 locations in tropical America and one location in tropical China. The sites represent 3 major agroecosystems: tropical semi-evergreen seasonal forest, tropical rainforest and savanna. The evaluation corroborated the poor performance of common centro on acid soils and identified new, superior C. pubescens accessions. Of particular interest was the outstanding performance of C. pubescens CIAT 15160 across ecosystems. Its dry matter production was superior to that of the C. pubescens controls and superior, or similar to that of the acid soil-tolerant C. acutifolium control accessions CIAT 5277 (except for the rainforest ecosystem) and CIAT 5568. CIAT 15160 produced high seed yields in the seasonal forest and savanna ecosystems, and was selected for advanced testing in all 3 ecosystems. In addition, the following accessions are recommended for further evaluation such as in grass-legume associations under grazing, cut-and-carry systems, protein banks or as soil cover: CIAT 15150, 5172 and 5634 for the tropical semi-evergreen seasonal forest eco-system; CIAT 15470, 15872 and 5172 for the tropical rainforest ecosystem; and CIAT 15150 and 5169 for the savanna ecosystem.
The aforementioned accessions, with the exception of CIAT 5634 and 15470, were also identified as the most promising regarding DM productivity and environmental adaptation in an analysis of adaptability performed across the three ecosystems. There was a positive correlation (r = 0.61) between DM yields and adaptability indices.