Use of light for the fodder plant in pasture, with emphasis on tropical

Abstract

Photosynthesis is the result of integrated processes that occur within the canopy associated with light interception as leaf area index, leaf angle, transmission properties of light on leaf characteristics, solar radiation (relation between direct and diffuse light and angle of radiation incident) and vertical distribution of leaf area and volumetric density of morphological components along the canopy, such as structural and spatial arrangement of morphological components. C3 grasses saturated with light at light intensities lower than C4 species. The optimal use of sunlight incident is one that occurs when the foliage of a dense canopy receives light intensity uniform and relatively low, and the basal leaves remaining in the light compensation point. The value of leaf area index which provides 95% light interception and in which the value of TCC is at maximum, is defined as "critical". Below the leaf area index great growth rates of crop are dependent on leaf area index and are more reduced when the interception of incident light is incomplete. Forage canopy architecture also defines the degree of exposure of leaves to light. The angle of leaf insertion affects the extent of penetration of solar radiation in the canopy. The frequency of grazing, affects the photosynthetic potential of the canopy causing delay in regrowth. The architecture of plants and the canopy of tropical grasses suffer changes related to season, physiological state of plants, and farming and grazing regime, so the use of light by the community of plants in a pasture is dependent on changes in these factors.