ECOPHYSIOLOGICAL STUDIES IN HESPERALOE-FUNIFERA (AGAVACEAE) - A POTENTIAL NEW CAM CROP - THE EFFECT OF LIGHT AVAILABILITY ON PHOTOSYNTHESISAND GROWTH

Hesperaloe funifera (Agavaceae) is being investigated as a new special ty-fiber crop for arid lands. The objective of this study was to exami ne the effects of reduced solar radiation on photosynthesis and growth in this CAM species. Peak CO2 uptake integrated through 24 h was foun d to be highest during the fall. Although shading greatly reduced CO2 uptake in fall and winter, the decrease was not statistically signific ant for the spring and summer. Total biomass was significantly differe nt for the three light treatments, with average fresh weights of 5243 g, 4488 g, and 3671 g for the full-sun, 53%-sun, and 20%-sun treatment s, respectively. The greatest differences were found in the crown grow th, which would affect future production of both leaves and flower sta lks. Photosynthesis and growth results suggest that the cultivation of Hesperaloe funifera will be favored in well-lit environments characte ristic of arid or semiarid climates. (C) 1996 Academic Press Limited