ISHS Acta Horticulturae 162: Symposium on CO2 Enrichment
ANALYSIS OF THE GROWTH RESPONSES OF BEAN PLANTS TO ELEVATED CO2 CONCENTRATIONS |
| Authors: | P.A. Jolliffe, D.L. Ehret |
| Abstract:
The objective of this study was to use modern methods of plant growth analysis to investigate effects of CO2 enrichment on some components of vegetative growth. Bean plants (Phaseolus vulgaris L. cv. 'Pure Gold Wax') were grown in controlled environment chambers at 6 CO2 concentrations ranging from 340 ppm (0.62 g m-3) to 3 000 ppm (5.43 g m-3). CO2 enrichment treatments were continuous and commenced 11 d after planting. Measurements made on replicate plants harvested during the course of growth provided the primary data for plant growth analysis. Cubic spline regressions were fitted to the primary data, and the resulting growth curves were used to evaluate plant performance under different CO2 regimes. Dry weight per plant increased with increasing CO2 concentration up to 1 200 ppm and remained nearly constant above that level. Biomass duration accordingly exhibited a similar CO2 concentration response, but leaf area accumulation was much less sensitive to CO2. Most growth indices responded to CO2 enrichment, and one of the most prominent effects was a rapid and sustained decrease in specific leaf area. This effect was evident in all leaf components; hence, the ability to export additional dry weight accumulated in CO2-enriched leaves may be limited. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
