Forage production and chemical composition of Paspalum secans (Hitchc. & Chase) at different cutting plant ages

Abstract

The effects of plant age (14, 21, 28, 35, 42 and 49 days) on dry matter (DM) yield and chemical composition of Paspalum secans (Hitchc. & Chase), was evaluated under greenhouse with natural conditions of light and temperature. The experiment was conducted in a clayey Yellow Latosol with low fertility. The experimental design was randomized complete blocks with three replications. DM yields and regrowth, leaf area (LA), leaf area ratio (LAR) and leaf area index (LAI) increased consistently with growth  stage,  however the crude protein, phosphorus, calcium, magnesium and potassium contents, absolute and relative growth rates and the apparent assimilation rate decreased  as  plant  age. Apical meristem removing percentage increased with plant age. Aftermath regrowth showed close negative correlation with survival of apical meristems. The relations between DM yield, regrowth, LA, LAI and LAR with cutting plants age were described by the quadratic regression model. The maximum DM yield, regrowth, LA, LAI and LAR were estimated at 43,4; 35,4; 43,9; 44,5 and 44,3 days of regrowth, respectively. The absolute and relative growth rates were inversely proportional to cutting plant age. These data suggest that grass cutting at 35 to 42 days were optimal for obtain maximum yields and regrowth of rich forage and improved the grass morphological and physiological traits.