Phenological, agronomic and forage quality diversity among germplasm accessions of the tropical legume shrub Cratylia argentea

Abstract

Cratylia argentea (Desv.) O. Kuntze is a drought-tolerant tropical shrub legume that can help to ensure continuity of forage supply in smallholder systems either through direct grazing or as a cut-and-carry plant for fresh foliage or silage. A collection of 38 accessions was characterized agronomically and nutritionally. High diversity was detected between accessions. Time to flowering ranged from 217–329 days after transplanting seedlings to the field and from 129–202 days after cutting. Flowering is probably induced by reduction of day length. Seed production was high but variable. Dry matter production ranged from 190–382 g/plant in the rainy and from 124–262 g/plant in the dry season, content of in vitro digestible dry matter from 589–690 g/kg, crude protein content from 184–237 g/kg and fibre content from 403–528 g/kg (neutral detergent fibre, NDF), 240–335 g/kg (acid detergent fibre, ADF), and 9–13 g/kg (acid detergent fibre-bound nitrogen, N-ADF). Accessions CIAT 18674 and CIAT 22406 were identified as promising for further study. They were superior to the commercial cultivar in terms of dry matter (DM) production, particularly in the dry season. Further research is required to determine the prevailing reproduction strategy of C. argentea and to quantify outcrossing-rates. Multilocational trials with a selected set of accessions should be conducted under different environmental conditions.