Tiller demography and dry matter accumulation in coastcross grass under grazing

Abstract

The aim of this study was to identify patterns of tiller dynamics and to evaluate herbage dry matter accumulation in Coastcross Bermudagrass (Cynodon spp. cv. Coastcross) swards under grazing. Pasture responses evaluated were: tiller population density, tiller natality and mortality rates, proportion of flowering tillers and accumulation of herbage dry matter for Cynodon spp. cv. Coastcross. Experimental treatments corresponded to four steady state conditions characterized by sward surface heights of 5, 10, 15, and 20 cm maintained by sheep under continuous stocking and variable stocking rate. The shortest sward (5 cm) showed the highest tiller population density. The flowering was intense late winter and early spring. A high turnover in tiller population was observed during summer. A dry spell in November caused a decrease in tiller natality and increase in mortality rates. There was no treatment effect (P > 0.10) on rates of herbage dry matter accumulation.