Multilocational agronomic evaluation of selected Centrosema pubescens germplasm on acid soils

Twenty-three accessions of Centrosema pubescens selected for good performan ce on an infertile, acid soil were tested along with 2 control lines each o f C. pubescens and C. acutifolium at 18 locations in tropical America and o ne location in tropical China. The sites represent 3 major agroecosystems: tropical semi-evergreen seasonal forest, tropical rainforest and savanna. T he evaluation corroborated the poor performance of common centro on acid so ils and identified new, superior C. pubesecens accessions. Of particular in terest was the outstanding performance of C. pubescens CIAT 15160 across ec osystems. Its dry matter production was superior to that of the C. pubescen s controls and superior or similar to that of the acid soil-tolerant C. acu tifolium 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 eco systems. In addition, the following accessions are recommended for further evaluation such as in grass-legume associations under grazing, cut-and-carr y systems, protein banks or as soil cover: CIAT 15150, 5172 and 5634 for th e tropical semi-evergreen seasonal forest ecosystem; CIAT 15470, 15872 and 5172 for the tropicai rainforest ecosystem; and CIAT 15150 and 5169 for the savanna ecosystem. The aforementioned accessions, with the exception of CIAT 5634 and 15470, w ere also identified as the most promising regarding DM productivity and env ironmental adaptation in an analysis of adaptability performed across the t hree ecosystems. There was a positive correlation (r = 0.61) between DM yie lds and adaptability indices.