Genotypic differences in forage quantity and quality of canopy strata in napiergrass (Pennisetum purpureum Schumach)

Abstract

To assess grazing suitability of napiergrass genotypes across real dwarf Taiwan 7734 (7734), semidwarf (DL) and normal-tall Merkeron (ME), yield and quality attributes were determined in canopy strata. Plant densities of 7734, DL, and ME were 4, 2, and 1 plants m -2 , respectively, and relative light intensity (RLI) and dry weight of plant fractions were obtained by stratified clipping at the first and second cuttings in early September and late November, respectively. Results of this study revealed that plant height was in the order of ME (199 cm), followed by DL (128 cm) and 7734 (88 cm) at the first cutting, and 7734 tended to have higher tiller density, dry matter yield, and leaf area index than DL and ME at both cuttings. Canopy RLI in 7734 tended to decrease higher with strata than in DL and ME, which was corresponded with the lowest K in 7734, followed by DL and ME at both cuttings. Genotype 7734 had the highest digestibility and crude protein concentration, and lowest structural carbohydrate concentrations across genotypes, which would be favorable to grazing use by breeding beef cows.