The Influence of Natural Canopy Density on the Growth of White Clover, Trifolium repens

Abstract

Two genotypes of white clover, Trifolium repens, were propagated clonally and grown under grass or woodland canopies. Canopy densities varied such that they transmitted a complete range (0 to 100%) of the available photosynthetically active radiation (PAR). As % PAR decreased (i.e. with more shading) the development of branches was suppressed, and internode and petiole elongation increased. In general, however, the responses were non-linear, and elongation of internodes and petioles decreased again at the lowest values of % PAR. The genotype from the open habitat was, in general, more sensitive to variations in % PAR under lower light conditions. It reached maximum internode and petiole elongation under higher light conditions than did the genotype from the more shaded habitat (...)