Combining Winter Hardiness and Forage Yield in White Clover (Trifolium repens) Cultivated in Northern Environments

White clover (Trifolium repens) is an important component of sustainable livestock systems around the world. Its exploitation for agriculture in the northern, marginal areas is, however, currently limited by the lack of cultivars that combine persistence and high production potential. The aims are to investigate whether it is feasible to create breeding material of white clover for these areas by combining winter hardiness of northerly populations with good yielding ability of more southerly cultivars.