Morphogenesis of Tanzania guinea grass under nitrogen doses and plant densities

• Main Authors: Thiago Gomes dos Santos Braz, Dilermando Miranda da Fonseca, Fabrício Paiva de Freitas, Janaina Azevedo Martuscello, Manoel Eduardo Rozalino Santos, Márcia Vitória Santos, Vinícius Valim Pereira
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Zootecnia 2011-07-01
• Series: Revista Brasileira de Zootecnia
• Subjects: fertilization; light interception; morphogenetic characteristics; structural characteristics; Panicum maximum
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000700004

The objective of this work was to evaluate effects of nitrogen fertilization and plant density on morphogenesis of Tanzania guinea grass. It was used a random block design with 12 treatments and two replications in a 4 × 3 factorial arrangement, with four doses of nitrogen (N) (without N application, 80, 160 or 320 kg/ha.year) and three plant densities (9, 25 or 49 plants/m²). Harvest was performed at 25 cm from the ground when the canopy intercepted 95% of the incident light. Rates of leaf appearance and pseudostem elongation were positively and linearly influenced by nitrogen, whereas phillochron and leaf life span were influenced linearly and negatively. Leaf elongation responded positively to two factors, whereas leaf senescence rate and number of live leaves were not influenced by the factors evaluated. Number of total, basal and aerial tillers were greater at the density of 9 plants/m² and at the nitrogen dose of 320 kg/ha.year. Nitrogen increases production of leaves and tillers in Tanzania guinea grass defoliated at 95% of light interception, but high density of plants reduces the number of tiller per bunch.