Low temperature growth in the field of Trifolium repens ecotypes from northern latitudes.
In studies on the low-temp. growth of 13 ecotypes and of the cv. S184 of T. repens at 2 locations, one at 70 m and the other at 230 m alt. in NE England, 1 ecotype originating from 700 m alt. in the UK showed exceptional growth at both locations. This ecotype appeared to partition its growth into shoot components in autumn in a manner different to that in cv. S184, which appeared to influence subsequent spring growth. Ecotypes originating from low alt. showed frost injury at the upland location and this partly explained the paucity of clinal relationships between growth at low temp. and winter temp. at the place of origin. It is suggested that flower production by lowland ecotypes may adversely effect potential growth in autumn. It appeared that T. repens ecotypes from lowland areas were not well adapted to the upland environment despite their ability to grow well at low temp. in growth cabinets.