Frost tolerance of Trifolium species

Abstract

Thirteen Trifolium species were artificially frosted at -4, -8, -12, and -16°C in controlled environment rooms. This was carried out in such a way that soil freezing was avoided and only shoots were frosted. Frost tolerance was primarily assessed as the percentage of dead to total leaf dry weight present 1 week after frosting. Trifolium arvense, T. dubium, and T. hybridum were the most frost-tolerant, whereas T. ambiguum, T. subterraneum, T. glomeratum, T. vesiculosum, and T. cernuum were the most frost-sensitive, based on the temperature required to kill 50% of leaves. Trifolium ambiguum may have been particularly sensitive to frosting because of its poor vigour (size). © 1995 Taylor & Francis Group, LLC.