Effects of different concentrations of atmospheric CO₂on growth and yield components of wheat

Abstract

Summary Growth and yield components of a semi-dwarf spring wheat ( Triticum aestivum L., cv. GWO 1809) were determined under three different atmospheric CO 2 a concentrations (350, 675 and 1000 μ1/1) in controlled environment chambers of the Duke University Phytotron. CO2 enrichment enhanced tiller and head emergence and increased the number of head-producing tillers and the total dry weight of the plants. Total leaf area, stem height and root/shoot ratio of the plants were greater at high CO 2 concentrations than at low. Net assimilation rate (NAR) increased with increasing CO 2 concentration and decreased with plant size. There was little effect of CO 2 enrichment on leaf weight ratio (LWR) and leaf area ratio (LAR) and no significant effect on specific leaf area (SLA). The weight and number of seeds were significantly higher with increasing CO 2 concentration. The results of this study provide evidence that important changes in plant growth and development may occur during the next century if global CO 2 enrichment continues. Some of these changes would have important ecological impact in natural and managed ecosystems in the future.