Perennial legumes for the high rainfall zone of eastern Australia. 1. Evaluation in single rows and selection of Caucasian clover (Trifolium ambiguum M. Bieb.)

Abstract

A range of perennial legume species, including Trifolium ambiguum, T medium, Astragalus cicer, Coronilla varia, Lotus corniculatus, L. pedunculatus, and Lespedeza cuneata, were evaluated in glasshouse and field trials in 1989-92 at Armidale, New South Wales. Hexaploid germplasm of T. ambiguum was subjected to selection for increased seedling vigour, early biomass production and profuse flowering in glasshouse screening and spaced plant field nurseries. On an acid, solodic soil, T. ambiguum and T. medium grew modestly, Lotus spp. grew vigorously initially, but died out within 3 years, A. cicer and C. varia failed to persist beyond 1 year, but isolated plants of Lespedeza cuneata thrived. On an acid, freedraining, red-basalt soil, all accessions grew vigorously until early 1991. During the succeeding drought, Lotus sp. died out, A. cicer thinned out on the acid soil, but T. ambiguum, T medium, and C. varia remained persistent and productive. A large nursery of A. cicer accessions on the same soil limed to 5 t/ha before planting remained vigorous to the present. Superior hexaploid material of T ambiguum selected from spaced plants, originated chiefly from CPI 43909 and the ARS-2678 germplasm collection from Utah, USA.