Growth and persistence of Mediterranean genotypes of midseason-late maturing subterranean clover (Trifolium subterraneum) in Victoria

Abstract

Forty-two midseason-late maturing subterranean clover genotypes from the Mediterranean basin, 12 commercial cultivars, 2 bulk treatments and a blank control were sown in small plots in 1983 at the Pastoral Research Institute, Hamilton, Vic. (10.5 m2), and at the Rutherglen Research Institute, Rutherglen, Vic. (7.0 m2), to assess seasonal yield and persistence over 3 years. Perennial ryegrass cv. Ellett was sown as a companion grass at Hamilton. At both sites, but particularly at Hamilton, several genotypes were identified which showed considerable improvement over commercial cultivars. Some genotypes, although late maturing, were as productive as the best commercial cultivars in autumn and winter (e.g 2.06-2.38 t DM/ha) and were also highly productive (e.g. 3.46-3.94 t DM/ha) in spring (e.g. CPI 89822 H, 89774 F [Sardinia], 68103 H [Portugal] and GF 073.2 [Corsica] at Hamilton and CPI 89880 F, 89855 G, 89880 J [Sardinia] and GF 144.3 [France] at Rutherglen). Seed production of some genotypes was superior to that of the commercial cultivars (P= 0.01). Trikkala, Larisa and Karridale were the cultivars with the largest seed banks at both sites at the end of the third year. Nine of the 13 genotypes measured had seed banks at least as large as Trikkala (36 1 kg/ha) at Hamilton (e.g. 89774 F, 431 kg/ha; 89777 C, 402 kg/ha). All 10 genotypes measured at Rutherglen had seed banks at least as large as Karridale (1298 kg/ha) (e.g. 89880 J, 1717 kg/ ha; and 89820 D, 1578 kg/ha). As a result of this work and similar studies in Western Australia, New South Wales, South Australia and Tasmania, 13 late-maturing genotypes have been chosen for advanced evaluation prior to cultivar release about 1990.