2011). Phyllochron and leaf lifespan are morphogenic pro-cesses that control growth and development of plants by determining leaf area index and thus light interception by the sward (Lemaire and Chapman 1996). Both char-acteristics can be used as tools for pasture management and are influenced by management practices, like nitro-gen fertilization. However, few studies have examined these characteristics for forages under a tree canopy (Paciullo et al. 2008), particularly when using light interception (LI) as a criterion for cutting frequency. Under full sun, rotational stocking using 95% canopy LI has been recommended for using C4 species to their fullest potential and to optimize ruminant weight gains on pastures (da Silva and Carvalho 2005). The aim of our work was to determine the effects of shading (5-year-old plantation of