Development of white clover (Trifolium repens L.) cultivar Grasslands Challenge (G23)

Abstract

Grasslands Challenge (Trifolium repens L.) white clover was developed to incorporate potential growth benefits, and disease resistance, in two double cross hybrids (Mediterranean × New Zealand) identified in evaluations at Kaikohe. Thirty-three elite selections of hybrids and New Zealand material were polycrossed for seed production. Progeny testing resulted in 27 parental lines with improved resistance to leaf disease and stem nematode (Ditylenchus dipsaci) relative to Grasslands Pitau. Testing of the maternal lines for seedling characteristics resulted in the deletion of one parent. A bulk line was evaluated in mini plots, and a hill country grazing trial, and showed improved growth to the control. In a grazing trial conducted in the Manawatu, Challenge showed outstanding winter production. The selection has a high stolon density in combination with a medium to large leaf size. This will allow Challenge to recover quicker from drought stress and grazing pressure. The plant type and early results indicate Challenge will be best suited to a rotational grazing management, particularly in regions where significant cool-season growth occurs. Plant Variety Rights were granted in 1997, and commercial seed should be available in 1998. Keywords: Grasslands Challenge, leaf disease, Mediterranean hybrids, stem nematode, Trifolium repens