Comparative productivity of Trifolium subterraneum and T. yanninicum in south-western Victoria

Abstract

Two cultivars of Trifolium subterraneum (Woogenellup and Mt Barker) and three cultivars of T. yanninicum (Yarloop, Trikkala and Larisa) were sown in swards and mown to measure yields over 4 years at three sites (Beeac, Cherrypool and Hamilton) on old improved pasture land in south-western Victoria. T. yanninicum (cv. Meteora) was also tested at the Hamilton site and four other cultivars of T. subterraneum (Nungarin, Daliak, Seaton Park and Esperance) were also tested at the Cherrypool site. At Beeac and Hamilton two separate trials were sown on areas representing poorly-drained (flat) and better-drained (crest) aspects. T. yanninicum was consistently more productive than T. subterraneum at all sites. The most productive cultivars were Trikkala and Yarloop at both Beeac and Cherrypool (mean annual rainfall about 6 13 mm), and Larisa and Yarloop at Hamilton (mean annual rainfall 703 mm). Mt Barker produced less than any other cultivar at Beeac and Hamilton. At Cherrypool, Nungarin, Mt Barker and Daliak produced less than other cultivars. The seasonal yields of Yarloop were particularly high in autumn and winter at all sites, whereas those of Larisa were high in spring. Mt Barker grew poorly in winter. At Hamilton, the yields of clover from T. yanninicum were similar on the crest and on the flat, but the more productive cultivar of T. subterraneum, Woogenellup, produced less on the flat than on the crest during autumn (P< 0.05). Although all cultivars regenerated after the 1982 drought, at Cherrypool, where the drought was severe, the hard-seeded early cultivar, Daliak, and the hard-seeded early mid-season cultivars, Seaton Park and Esperance, were most successful in terms of plant density.