Does Elevated CO2 Accelerate Barley Flag Leaf Senescence to Help Increase Grain Yield?
Reference Fangmeier, A., Chrost, B., Hogy, P. and Krupinska, K. 2000. CO2 enrichment enhances flag leaf senescence in barley due to greater grain nitrogen sink capacity. Environmental and Experimental Botany 44: 151-164. What was done Barley (Hordeum vulgare L. cv. Alexis) plants were grown in containers placed within open-top chambers receiving atmospheric CO2 concentrations of 360 and 650 ppm to study the effects of elevated CO2 on yield production and senescence in this important agricultural grain crop. In addition, plants were subjected to a high and low nitrogen fertilization regime to see if nitrogen availability interacted with elevated CO2 to affect any of these processes. What was learned Elevated CO2 stimulated barley growth and biomass production in both nitrogen regimes. In fact, it increased total grain yield by 48 and 31% in the low and high nitrogen regimes, respectively. Thus, elevated CO2 had the greatest relative impact on yield when plants were grown under the less-
