When cover crops are grown under plantation crops, the quality and quantity of light reaching the cover crop canopy are important factors that limit the growth, development, and persistence of cover crops. Cover crops are grown as understory plants hence they do not receive full sunlight and as upper story trees grow the amount of photosynthetic photon flux density (PPFD) received at the cover crop canopy is reduced. Cover crops that tolerate low irradiance have a better chance of growing and persisting under plantation crops. Limited attention has been given to understanding the growth, physiology, and nutrition of various cover crops under varying light intensities. An experiment was undertaken in the greenhouse to assess the effects of PPFD on the growth, physiological and nutritional parameters of nine tropical perennial leguminous cover crops.