SALMAN, A. K. D.

SANTOS, L. O.

SOUZA, J. P.

TOWNSEND, C. R.

Repository Open Access to Scientific Information from Embrapa

  Morphogenetic and structural characteristics of Brachiaria brizantha cv. Marandu subjected to levels of shading  Claudio R. Townsend*1, Leilane O. Santos2, Josilane P. Souza3, Josiline P. Souza4, Ana Karina Salman1  1Researcher at Brazilian Agricultural Research Corporation-Embrapa Rondônia; 2Master's Federal University of Lavras; 3Master's Federal University of the Jequitinhonha and Mucuri; 4Student of Animal Science of Integrated Schools Aparicio Carvalho - FIMCA * claudio.townsend@embrapa.br  To evaluate the response of B. brizantha (Urochloa brizantha) cv. Marandu  to three shading levels (0, 20 and 50%), an experiment was conducted at Embrapa Rondônia in Porto Velho-Brazil; in randomized complete block design with replications, three blocks and five replications. The dynamics of leaf development followed the methodology of marked tillers, if conducting weekly evaluations, for 36 days elapsed from the beginning of September and early October 2011, when the determined condition of the leaves (expanding, expanded in senescence and senesced), and told, we measured the length of leaf blade and heights sheath and tiller. From this information we determine the morphogenetic traits: rates the of leaves expansion (LER-cm of laef.tiller-1.GD-1), senescence (LRS-cm of laef.tiller-1.GD-1) and appearance (LAR-laef.tiller-1.GD-1), phyllochron (PHILO-GD.laef -1.tiller-1), leaf lifespan (LLS-GD.laef-1.tiller-1) and rate of stem elongation (RSE-cm of stem.tiller-1.GD-1); as well as structural characteristics: total amount (TL-n° laves.tiller-1) and green leaves (GL-n° laves.tiller-1), leaf blade length (LBL-cm.laef-1) and height of tillers (HT-cm.tiller-1). The means were submitted to analysis of variance and compared by Tukey test (P 0.05%), and regression analysis. The LER, RSE and LLS were influenced by shading, with the highest values observed under high shading towards more levels,  and responded to that factor as models (P ≤ 0.05): LER = 0.071 + 0.002 x (R² = 79); RSE = 0.047 + 0.0018 x (R² = 72) and LLS = 1.271 + 8.969 x (R² = 67). The more morphogenetic traits were not affected and neither responded to restriction levels of solar radiation. The behavior of these characteristics acted on the structural attributes determined by the same, being detected effect of shading on TL, GL, LBL and HT, with the highest values observed under high shading and the smallest full sun, with responses given by the models (P ≤ 0.05): GL = 4.7 + 0.0314 x (R² = 75); LBL = 23.5 + 0.272 (R² = 87) and HT =  40.5 + 0.875 x (R² = 89). Demonstrating that the grass assumed adaptation strategies the condition of the shaded, what gives B. brizantha cv. Marandu potential for use in silvopastoral and integrated crop-livestock-forest systems. Demonstrating that the grass assumed adaptation strategies the condition of the shaded, which seek maximize interception and absorption of solar radiation, through the allocation and arrangement of their photosynthetic apparatus (f.e. increasing the height of tillers and leaf length), and increasing the photosynthetic tissue (f.e. maintaining a higher amount of green leaves). What gives the Marandu grass potential for use in silvopastoral and integrated crop-livestock-forest systems.  Keywords: forage, light intensity, integrated crop-livestock-forest, silvopastoral systems.  Acknowledgments: Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq 

Morphogenetic and structural characteristics of Brachiaria brizantha cv. Marandu subjected to levels of shading.

http://www.alice.cnptia.embrapa.br/alice/bitstream/doc/995673/1/6WZQ.pdf

Morphogenetic and structural characteristics of Brachiaria brizantha cv. Marandu subjected to levels of shading.

Abstract

Similar works

Full text

Available Versions

Repository Open Access to Scientific Information from Embrapa