Evaluation of clovers in dry hill country 3. Regeneration and production of subterranean clover at Whatawhata, New Zealand

Abstract

Nine cultivars of subterranean clover (Trifolium subterraneum L.) were evaluated on steep, inter-track areas located on a north-west-facing hillside that received 1200–1500 mm annual rainfall. For 4 years, cultivars were compared under two contrasting spring grazing managements, viz: on-off sheep grazing to a 2–3 cm height (RG) or continuous sheep grazing to a 1–2 cm height (CG). Common on-off grazing occurred for the remainder of the year. Measurements of herbage production and subteranean clover plant density were made for 4 and 6 years respectively. ‘Tallarook’, ‘Howard’, and ‘Mt Barker’ were the most reliable cultivars in terms of regeneration under both managements. Regeneration of ‘Trikkala’, ‘Woogenellup’, ‘Clare’, ‘Larisa’, and ‘Nangeela’ was poor. Plant densities in June of more than 150–200/m² seemed necessary to achieve maximum production. ‘Seaton Park’ regenerated poorly under CG management, and ceased growth earlier than other cultivars under RG management. ‘Tallarook’ and ‘Howard’ were consistently top performers in terms of yield; ‘Woogenellup's’ productive ranking declined with time. For steep hill country that receives high annual rainfall and is closely grazed during spring, the most suitable subterranean clover cultivar should reseed during late October–November, be prostrate in crown and runner habit, and be low in oestrogenic content.

Keywords:

• subterranean clover
• Trifolium subterraneum
• hill country
• grazing management
• cultivar evaluation