Morphogenetic and structural characteristics of xaraes palisadegrass submitted to cutting heights

Braulio Maia De Lana Sousa,Sila Carneiro Da Silva,Domicio Do Nascimento Júnior,André Fischer Sbrissia,Carlindo Santos Rodrigues,Dilermando Miranda Da Fonseca,Hélida Christhine De Freitas Monteiro

doi:10.1590/s1516-35982011000100008

Braulio Maia De Lana Sousa, Sila Carneiro Da Silva + Show 5 more

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https://doi.org/10.1590/s1516-35982011000100008

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Abstract

The objective of this work was to evaluate the morphogenetic and structural characteristics of xaraes palisadegrass submitted to three cutting heights (15, 20 and 25 cm) when the sward reached 95% of light interception during regrowth. The experiment was carried out according to a complete randomized block design with three replications. The sward surface height under the cutting condition of 95% of light interception was very homogeneous with values around 30 cm. The increase in cutting height reduced the leaf elongation rate and the number of live leaves but increased stem elongation rate. As the cutting criterion was the same, before the intense competition for light, the variation in the cutting severity had a small influence on the morphogenetic and structural characteristics of this grass. In the summer, due to the better growth conditions, the plants presented a higher tissue renewal, which was characterized by a higher leaf elongation rate, reduced leaf lifespan and leaf senescence rate when compared to the other season of the year. Under intermittent defoliation conditions, the regrowth of xaraes palisadegrass can be interrupted at a sward height of 30 cm (frequency) keeping a residual height of 15 cm.

Highlights

The xaraes palisadegrass (Brachiaria brizantha) was released in 2002 by EMBRAPA – Gado de Corte to provide another forage option to form pastures in Central Brazil (Valle et al, 2003)
Recent researches in Brazil (Giacomini et al, 2009a, b; Da Silva et al, 2009), markedly on the genera Brachiaria and Panicum, indicate that the 95% of light interception by the sward can be considered as the ideal moment to interrupt regrowth
The use of light interception, already studied for temperate climate grasses (Korte et al, 1982), has been successfully applied for tropical grasses under intermittent stocking (Da Silva & Nascimento Júnior, 2007). This condition presented a high relationship with the sward surface height (Carnevalli et al, 2006; Barbosa et al, 2007; Sousa et al, 2010), indicating that sward height targets could be used as a practical and useful guide to tropical grazing management purposes

Summary

Introduction

The xaraes palisadegrass (Brachiaria brizantha) was released in 2002 by EMBRAPA – Gado de Corte to provide another forage option to form pastures in Central Brazil (Valle et al, 2003). The use of light interception, already studied for temperate climate grasses (Korte et al, 1982), has been successfully applied for tropical grasses under intermittent stocking (Da Silva & Nascimento Júnior, 2007). This condition presented a high relationship with the sward surface height (Carnevalli et al, 2006; Barbosa et al, 2007; Sousa et al, 2010), indicating that sward height targets could be used as a practical and useful guide to tropical grazing management purposes

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