Increased [CO 2] does not compensate for negative effects on yield caused by higher temperature and [O 3] in Brassica napus L

• Published in: European journal of agronomy Vol. 35; no. 3; pp. 127 - 134
• Main Authors: Frenck, Georg, van der Linden, Leon, Mikkelsen, Teis Nørgaard, Brix, Hans, Jørgensen, Rikke Bagger
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2011; Elsevier
• Subjects: Agronomy. Soil science and plant productions; ambient temperature; atmospheric chemistry; Biological and medical sciences; biomass production; Brassica napus; Brassica napus var. napus; breeding; Carbon dioxide; Crop yield; cultivars; food production; Fundamental and applied biological sciences. Psychology; genotype; Oilseed rape; Ozone; prediction; seed yield; Temperature; Oilseed rape; Brassica napus; Ozone; Temperature; Crop yield; Carbon dioxide; Brassica napus var. oleifera; Increase; Cruciferae; Dicotyledones; Angiospermae; Spermatophyta; Yield; Oil plant (vegetal)
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/j.eja.2011.05.004

► We analysed the responses in yield and biomass of four cultivars of oilseed rape. ► Plants were tested under 5 multi or single factor combinations of increased [CO 2], temperature and [O 3]. ► The used combinations of factors are new in an effect-experiment with a crop. ► Results are of interest for predictions of the future primary production. The projected changes of atmospheric composition and associated climatic parameters will challenge the agricultural production in ways, which existing crop populations have not previously experienced. Therefore, understanding the responsiveness to changes of multiple environmental parameters in existing genotypes is vital. In this study, the responses in yield and biomass production of four different cultivars of oilseed rape ( Brassica napus L.) were tested under five different combinations of increased [CO 2] (700 ppm), temperature (+5 °C) and [O 3] (+40 ppb). Especially the multifactor treatments are relevant for predictions of the future production, as they mimic the multidimensional environmental changes that are expected within this century. All treatments were given the same amount of water, which mimicked future limited water availability e.g. in treatments with elevated temperature. The biomass and yield parameters were found to be significantly cultivar dependent. However, in all cultivars elevated temperature caused a significant reduction in yield parameters, while biomass was not affected significantly. Elevated [CO 2] increased the vegetative biomass significantly, but seed yield was only significantly enhanced in one of the four cultivars studied. Increased [O 3] did not have significant effects on any of the cultivars. In general, the negative effects of a 5 °C temperature elevation on yield could not be compensated by elevated [CO 2], when simultaneously applied in multifactor treatments. The evaluation of cultivar differences in productivity under elevated [CO 2] in combination with increased temperatures and [O 3] is necessary to derive at a realistic prediction for the future food and biomass production and for the selection of cultivars providing an adaptation potential to environmental change. Our results suggest that future breeding of B. napus should be based on old cultivars, since more modern varieties seem to have lower potentials to respond to CO 2 and thus counteract the detrimental effects of yield reducing environmental factors such as temperature and O 3.