Pubvet (Jun 2022)
Forage productivity and morphogenesis of Megathyrsus maximus x M. infestum cv. Massai under phosphate fertilization
Abstract
The effect of phosphorus fertilization (0, 30, 60, 90 and 120 kg of P2O5 ha-1) on green dry matter (GDM) yield and morphogenetic and structural characteristics of Megathyrsus maximus x M. infestum cv. Massai was evaluated under natural field conditions in Roraimas´s savannas. Phosphorus fertilization increased significantly (P<.05) GDM yields, P concentrations, tiller populational density (TPD), live leaf tiller-1 number (LLTN), avarege leaf size (ALS), leaf area index (LAI), leaf senescence rate, leaf appearance rate (LAR) and elongation rates (LER). Maximum GDM yields, LAR, LER, TPD, LLTN, LAI and ALS were obtained with the application of 101.7; 62.5; 68.7; 80.8; 66.5; 91.7 and 74.1 kg of P2O5 ha-1, respectively. The P critic level, related to 80% of GDM maximum production, was estimated at 1.652 g kg-1. The P efficiency utilization was inversely proportional to the P rates applied.
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