Canopy shade is a important component of weed- crop interference, thus effect of radiation in terms of quality (wavelenght) and quantity (irradiance, photon flux) on the diversity of plant species is a serious constraint to production and crop management. The sugarcane canopy closes at about three months after planting, and population of plants under the canopy changes in number and diversity depending on the ability of some species to avoid or escape shade by a series of developmental changes at plant and population levels. Under field conditions, for each sugarcane cycle, recognition of the species diversity as well as their strategies for shade avoidance before and after canopy closure, is relevant to agricultural applications and plant biology. In this chapter, light profiles under the canopy are analyzed by means of hyperspectral analysis and how changing light conditions in a close-in canopy may affect the development and diversity of plant species as seen in the field at the individual level.Fonacit proyecto S1-2002000512