Abstract
Canopy dynamics in a bahiagrass (Paspalum notatum Flugge) pasture under cattle grazing were investigated for 2 years in terms of herbage mass and relating structural components, i.e. tiller density, tiller weight, lamina weight per tiller, stem (inclusive of leaf sheaths) weight per tiller, number of laminae per tiller, mean lamina length and mean lamina weight per unit length, in an effort to evaluate contributions of the individual components to variations in herbage mass. Herbage mass, tiller weight, lamina weight per tiller, stem weight per tiller and mean lamina length showed large variations with time (CV=0.46-0.67), being high in summer-autumn and low in other seasons. On the contrary, tiller density, number of laminae per tiller and mean lamina weight per unit length were least variable (CV=0.07-0.10). Variations in herbage mass were associated with variations in tiller weight (r=0.818), lamina weight per tiller (r=0.742), stem weight per tiller (r=0.753) and mean lamina length (r=0.680). Tiller weight was highly correlated with both lamia weight and stem weight per tiller (r=0.874-0.939), and lamina weight per tiller with mean lamina length (r=0.973). Thus, variations in herbage mass were attributed to variations in tiller weight, which originated from variations in mean lamina length and stem weight per tiller.
