CO2 vs. UV Radiation: Effects on Yield Components of Canola
Tohidimoghadam, H.R., Ghooshchi, F. and Zahedi, H. 2011. Effect of UV radiation and elevated CO2 on morphological traits, yield and yield components of canola (Brassica napus L.) grown under water deficit. Notulae Botanicae Horti Agrobotanici Cluj-Napoca 39: 213-219.
Based on their analysis, the authors report that "water stress significantly decreased yield and yield components, oil yield, protein percentage, height, specific leaf area and the number of branches," but that elevated CO2 "increased the final yield, 1000-seed weight, oil percentage, oil yield, height, specific leaf area and number of branches," while UV radiation "decreased the yield, yield components, oil and protein percentages and growth parameters." They also note that "the highest seed weight was obtained from the 'Talaye' cultivar treated with compete irrigation and elevated CO2 and grown under sunlight radiation," while "the seed weights of both cultivars visibly decreased due to UV-B, UV-C and water stress under an ambient CO2 concentration."
The three Iranian researchers state that "an increase in UV exposure deceases plant growth and development," but that "elevated CO2 ameliorate(s) the adverse effects of UV radiation in the final yield, seed weight, oil percentage, oil yield, plant height, specific leaf area and number of branches per plant," concluding that an increase in the atmosphere's CO2 concentration "could improve yield, yield components and growth parameters for plants subjected to elevated levels of UV radiation."