Growth dynamics and morphogenesis of Trachypogon plumosus under soil fertility correction levels and regrowth ages

• Published in: Agro@mbiente on-line Vol. 7; no. 1; p. 1
• Main Authors: Costa, Newton De Lucena, Moraes, Anibal De, Carvalho, Paulo César Faccio de, Monteiro, Alda Lúcia Gomes, Motta, Antônio Carlos Vargas, De Oliveira, Ricardo Augusto
• Format: Journal Article
• Language: English
• Published: Universidade Federal de Roraima 02-05-2013
• Subjects: Dry matter. Growth rate. Leaves. Tillering
• ISSN: 1982-8470; 1982-8470
• DOI: 10.18227/1982-8470ragro.v7i1.825

The effects of soil fertility correction levels (control, liming, fertilization and liming + fertilization) and regrowth ages (21, 28, 35, 42, 49, 56, 63, 70, 77 and 84 days) on growth dynamics, forage yield and morphogenetic and structural characteristics of Trachypogon plumosus were assessed in Roraima´s savannas. Dry matter yields (DMY), absolute growth rate (AGR), tiller population density (TPD), number of live leaves (NLL), final leaf length (FLL), leaf area index (LAI), leaf elongation rate (LER) and leaf senescence rate (LSR) increased consistently with regrowth age, while average growth rate (AvGR), and leaf appearance rate (LAR) were inversely proportional to regrowth age. The grass showed high responsiveness to the soil fertility improvement. Liming + fertilization or fertilization alone promoted higher DMY (2,116 and 1,759 kg ha-1), AGR (40.5 and 33.6 kg ha-1.day), AvGR (32.5 and 27.9 kg ha-1.day), NLL (5.5 and 4.9 leaf tiller-1), LAR (0.119 and 0.109 leaf day-1 tiller-1), LER (2.53 and 2.06 cm day-1 tiller-1), FLL (22.1 and 18.9 cm), LAI (2.64 and 2.83) and TPD (762 and 725 tillers m-2). To maximize the forage use efficiency and to prevent losses to leaves senescence, it is recommended a regrowth period between 56 to 63 days for fertilization and liming + fertilization, and 63 to 70 days for control or liming pastures.