Structural traits of elephant grass (Pennisetum purpureum Schum.) genotypes under rotational stocking strategies

Abstract

Despite the forage potential of elephant grass, controlling canopy structure during grazing has limited its use in pasture. This study was conducted to determine the effect of grazing frequency and post-grazing height on canopy structural characteristics of elephant grass genotypes. The treatments consisted of the factorial combinations of two dwarf elephant grass genotypes (BRS Kurumi and CNPGL 00-1-3), two levels of light interceptions (LI; 90% and 95%) at initiation of grazing, and two post-grazing heights (30 and 50 cm) arranged in a completely randomised design with three replications. The average pre-grazing canopy height ranged from 75 cm for BRS Kurumi to 127 cm for CNPGL 00-1-3. The interval between grazing events averaged 22 and 50 d for BRS Kurumi and CNPGL 00-1-3, respectively. The percentage of leaves was higher for BRS Kurumi compared to CNPGL 00-1-3, for the 30 cm vs 50 cm post-grazing height, and for 95% vs 90% LI. The genotype BRS Kurumi had greater tiller density (298 vs 107 tillers m⁻²), allowing faster recovery after grazing. The cultivar BRS Kurumi represents an attractive alternative for grazing use, and it should be managed, during the rainy season, using a pre-grazing canopy height of around 75 cm with a 30 cm post-grazing height.

Keywords: canopy height, forage density, leaf percentage, leaf:stem ratio, Pennisetum purpureum, rest period