Carbon isotope discrimination and water-use efficiency of six crops grown under wet and dryland conditions |
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Authors: | J. D. KNIGHT N. J. LIVINGSTON C. VAN KESSEL |
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Affiliation: | Department of Crop Science and Plant Ecology, University of Saskatchewan, Saskatoon, Saskatchewan, British Columbia;Department of Biology, University of Victoria, Victoria, British Columbia;Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada |
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Abstract: | Mustard (Sinapis alba L.), Argentine canola (Brassica napus L. cv. Westar), Polish canola (Brassica campestris L. cv. Tobin), pea (Pisum sativum L.), durum wheat (Triticum durum L. cv. Kyle) and soft wheat (Triticum aestivum L. cv. Fielder) were grown at Outlook, Saskatchewan, Canada, under irrigated and dryland conditions. Carbon isotope discrimination (Δ) and water-use efficiency (W), defined as grams of above ground dry matter produced per kilogram water used, were negatively correlated in the six field-grown crops. In irrigated plants Δ remained relatively constant (20–21‰) throughout the growing season. However, in dryland plants, Δ declined in response to the progressive depletion of stored soil water (Polish canola, 20-2-18-8‰; mustard, 19.9–18 5‰; pea, 19.9–17 2‰ durum wheat, 19.7–16.4‰; Argentine canola, 19.4–17.6‰; soft wheat, 19.0–17.4‰). Although there were genetic differences in Δ among the species, water availability was the major factor controlling Δ. |
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Keywords: | canola mustard pea wheat water-use efficiency 13C discrimination dryland irrigation |
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