Interspecific Competition in a Pecan-cotton Alley-cropping System in the Southern United States: Is Light the Limiting Factor?

Abstract

The manner in which light is intercepted by crop canopies and converted to structural dry matter can significantly affect primary production at a given site. A number of authors have investigated plant performance under different environmental conditions, including different levels of light, in alley cropping and similar agroforestry systems (Azam-ali et al. 1990; Monteith et al. 1991; Rosenthal and Gerik, 1991; Heitholt et al. 1992; Chirko et al. 1996; Gillespie et al. 2000; Jose et al. 2000). These studies have revealed strong linear relationships between photosynthetically active radiation (PAR, 400–700 nm) and dry matter production.