MISCONCEPTIONS ABOUT THE RELATION BETWEEN PLANT-GROWTH AND RESPIRATION

The relation between plant growth rate and respiration rate is readily derived from the overall chemical reaction for aerobic metabolism. Th e derived relation can be used to show that separation of respiration into growth (g) and maintenance (m) components is not a useful concept , g and m cannot be unambiguously measured or defined in terms of bioc hemical processes. Moreover, because growth yield calculations from bi ochemical pathway analysis, from biomass molecular composition, from b iomass heat of combustion, and from biomass elemental composition have not included all of the energy costs for biosynthesis, they are not a ccurate measures of the carbon cost for plant growth. Improper definit ions of growth-respiration relations are impeding the use of physiolog ical properties for prediction of plant growth as a function of enviro nmental variables.