The effects of plant density and frequency of cutting on the growth of cocksfoot (Dactylis glomerata L). I. The production of vegetative and reproductive tillers

Abstract

To study the effects of density and cutting frequency on the reproductive phase of cocksfoot (Dactylis glomerata L.) the plants of a clone were established on a geometric scale at nine spacings ranging from 4 to 17 in, between plants, which provided densities from 9 plants to 0.5 plant per sq ft. The plants were cut every 2, 4, or 8 weeks or cut once at the end of the growing season. The cut tillers were classified as vegetative or reproductive (elongating and heading). The number of vegetative tillers per plant was reduced by high density in all treatments. A change in cutting frequency from every 8 to every 4 weeks had little effect on numbers but cutting every 2 weeks led to a large reduction in numbers. The reproductive tillers were affected by the treatments much more than the vegetative tillers. At most densities, more reproductive tillers were produced by the regularly cut plants than by the plants cut once at the end of the season. The increase was attributed to destruction of the apical dominance of early reproductive buds that inhibit the development of further reproductive tillers. Very frequent cutting and high density delayed the incidence of the reproductive phase for many weeks. The optimal density for the production of reproductive tillers changed with time. It was often lower than for vegetative tillers.