The Effects of Elevated Atmospheric Carbon Dioxide and Water Stress on Light Interception, Dry Matter Production and Yield in Stands of Groundnut (Arachis hypogaea L.)
Stands of groundnut (Arachis hypogaea L.), a C3 legume, were grown in controlled-environment glasshouses at 28 °C (±5 C) under two levels of atmospheric CO2 (350 ppmv or 700 ppmv) and two levels of soil moisture (irrigated weekly or no water from 35 d after sowing). Elevated CO2 increased the maximu...
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Veröffentlicht in: | Journal of experimental botany 1993-12, Vol.44 (269), p.1763-1770 |
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Zusammenfassung: | Stands of groundnut (Arachis hypogaea L.), a C3 legume, were grown in controlled-environment glasshouses at 28 °C (±5 C) under two levels of atmospheric CO2 (350 ppmv or 700 ppmv) and two levels of soil moisture (irrigated weekly or no water from 35 d after sowing). Elevated CO2 increased the maximum rate of net photosynthesis by up to 40%, with an increase in conversion coefficient for intercepted radiation of 30% (from 1.66 to 2.16 g MJ-1) in well-irrigated conditions, and 94% (from 0.64 to 1.24 g MJ-1) on a drying soil profile. In plants well supplied with water, elevated CO2 increased dry matter accumulation by 16% (from 13.79 to 16.03 t ha-1) and pod yield by 25% (from 2.7 to 3.4 t ha-1). However, the harvest index (total pod dry weight/above-ground dry weight) was unaffected by CO2 treatment. The beneficial effects of elevated CO2 were enhanced under severe water stress, dry matter production increased by 112% (from 4.13 to 8.87 t ha-1) and a pod yield of 1.34 t ha-1 was obtained in elevated CO2, whereas comparable plots at 350 ppmv CO2 only yielded 0.22 t ha-1. There was a corresponding decrease in harvest index from 0.15 to 0.05. Following the withholding of irrigation, plants growing on a stored soil water profile in elevated CO2 could maintain significantly less negative leaf water potentials (P |
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ISSN: | 0022-0957 1460-2431 |
DOI: | 10.1093/jxb/44.12.1763 |