Components of the leaf area index of marandu palisadegrass swards subjected to strategies of intermittent stocking

Scientia Agricola

Alessandra Aparecida Giacomini²  Sila Carneiro Da Silva¹  Daniel Oliveira De Lucena Sarmento²  Cauê Varesqui Zeferino²  Júlio Kuhn Da Trindade²  Salim Jacaúna Souza Júnior²  Vítor Del'alamo Guarda²  André Fischer Sbrissia¹  Domicio Do Nascimento Júnior¹ 

[1] ,USP ESALQ

关键词: Brachiaria brizantha;    aerial tillers;    basal tillers;    site filling;    sward height;    Brachiaria brizantha;    altura do dossel;    perfilhos aéreos;    perfilhos basais;    site filling;   

DOI  :  10.1590/S0103-90162009000600002

来源: SciELO

【 摘 要 】

Leaf area index is the main sward characteristic related to the processes of light interception and competition in plant communities. The objective of this experiment was to quantify and evaluate the composition of the leaf area on tillers of marandu palisadegrass (Brachiaria brizantha cv. Marandu) subjected to strategies of intermittent stocking. The experiment was carried out in Piracicaba, state of São Paulo, Brazil, from October/2004 to December/2005. Swards were grazed at 95 and 100% canopy light interception (LI) to post-grazing heights of 10 and 15 cm, following a 2 ' 2 factorial arrangement with four replications in a randomised complete block design. Estimates were made of sward leaf area index, site filling, specific leaf area and the dimensionless ratio between tiller leaf area and volume (R), as well as the relative contribution of basal and aerial tillers to these variables. In early spring, values of leaf area index and specific leaf area were low when compared to the other seasons, and swards grazed at 95% LI presented higher site filling and specific leaf area than those grazed at 100% LI. This resulted in higher tillering activity and increase in leaf area index in late spring, indicating quick recovery and early return of swards grazed at 95% LI to growing conditions. Aerial tillers corresponded to an important morphological adaptation of marandu palisadegrass to increase its competitive ability. Treatment 100/10 resulted in the highest and 95/15 in the lowest R values throughout the experiment, suggesting an allometric pattern of growth of tillers during regrowth in order to compensate low tiller population and optimise the leaf area index. Grazing management practices can benefit from this knowledge by promoting ideal sward conditions to maximise and accelerate growth.

【 授权许可】

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