Grasslands Kopu II and Crusader: New generation white clovers

Abstract

Two recently released white clover cultivars, Grasslands Kopu II and Crusader, were compared with existing cultivars for at least 3 years in each of five field trials under rotational grazing by either dairy cows or sheep in the Waikato and Manawatu. Kopu II, a large-leaved cultivar with intermediate cyanogenesis and high stolon density relative to its leaf size, performed strongly under dairy grazing with high clover yields in summer, autumn and winter, and improved persistence in year 3 of these trials. Kopu II, along with Kopu and Sustain, also had high soluble carbohydrate content. Crusader is comparable to Huia in leaf size, but has higher cyanogenesis and stolon density than Huia. Crusader outperformed all other cultivars under sheep grazing with high clover yields in autumn, winter and spring. Under dairy grazing, Crusader performed very well in years 1 and 2 but did not perform as well as Kopu II in year 3. Both of these cultivars have performed well in international testing with Kopu II having high yield and stolon density under cattle grazing in Northern USA, while Crusader has been nationally listed in the UK based on NIAB trial results. Kopu II and Crusader represent the first of a new generation of white clover cultivars bred to perform well in both national and international markets. Keywords: breeding, cultivar, dairy, sheep, Trifolium repens, white clover