Dependence of potential productivity and efficiency for solar energy utilization on leaf photosynthetic capacity in crop species

Abstract

Comparison among various crop species was made of the reported high values in the maximum crop growth rate, maxCGR, obtained under very favorable field conditions at various locations in the world, in relation to the reported maximum leaf photosynthetic activity p0observed under natural conditions. Similar comparison was made of the mean CGR. Further, comparison was made of the solar energy utilization efficiency for the maxCGR, taking the solar radiation level into consideration. The following results were obtained: 1) A close second order regression of maxCGR on p0 seems to exist including all the available data, regardless of the C3 and C4 discrimination. This was interpreted to suggest the outstanding importance of p0 for determining the species difference in the potential crop productivity. 2) Similar but less close relationship was recognized between the mean CGR and p0. 3) Solar energy utilization efficiency corresponding to the maxCGR was shown to be higher in the C4 species than in the C8 species, with a few exceptions, after correcting the observed values to those at the same solar radiation level. Further, a very close correlation was found between p0 and the corrected Eu, suggesting the importance of p0 for determining the efficiency for solar energy utilization of crop species in the field. © 1981, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.