Evaluation of the cutting frequency and fertilization types on three elephant grass genotypes (Pennisetum purpureum ). 1. Yield and protein content

摘要

In order to evaluate the effect of the cutting frequency and types of nitrogen fertilization on three elephant grass genotypes, a field trial was carried in the Universidad de Los Andes farm, in El Vigia, Merida state, Venezuela, located at 67 masl. A random bocks design with three replications was used; treatments were two cutting frequencies (F1: 49 and F2: 63 days), three genotypes (G1: Taiwan A-146, G2: Morado, and G3: Maralfalfa) and three types of fertilization (N1: cow manure, equivalent to 91 kg N/ha/year, N2 and N3 urea with 343 and 686 kg N/ha/year). The FxG interaction was significant over pasture yield (TDM) and crude protein (CP). Yields were 40.9, 29.7, and 37.7 t DM/ha/year for G1, G2, and G3, respectively. Dry Matter (DM%) content was different (P<0.01) for FxG, with higher values obtained at F2 (21.5%) and G1 (20.4%). Crude protein content decreased with the regrowth age, and the relation CP = 17.7 - 0.18 x F(days) was estimated. It was concluded that higher yields were obtained with Taiwn A-146 and Maralfalfa with F2 and N2, while high CP content was obtained with Morado elephant grass and F1. Nitrogen fertilization increased forage yield and protein content of the three elephant grass genotypes.