Interactive Effects of Carbon Dioxide and Water Stress on Potato Canopy Growth and Development
- David H. Fleisher *,
- Dennis J. Timlin and
- Vangimalla R. Reddy
Reductions in potato (Solanum tuberosum L.) canopy growth are observed with mild water stress. Potato growth is enhanced by elevated atmospheric carbon dioxide ([CO2]), but interactions of [CO2] and water stress on canopy formation and dry matter partitioning have not been studied. Two soil-plant-atmosphere research (SPAR) experiments were conducted at 370 or 740 μmol mol−1 [CO2] and six different irrigations from 10 to 100% of the daily water uptake of the control. Increases in plant length from 23 to 111 cm at 60 d after emergence (DAE), leaf appearance duration from 38 to 71 d, leaf appearance rate from 0.5 to 0.93 leaves d−1, individual leaf area from 50 to 175 cm2, and lateral branch elongation were observed as irrigation increased. Values were generally smaller for elevated [CO2] plants under water stress. Biomass increased with irrigation from 73 to 346 g plant−2 The percentage allocated to the canopy increased with irrigation from 50 to 80% in ambient and 30 to 80% in elevated [CO2]. Despite decreased canopy size, elevated [CO2] plants produced similar total biomass, but higher yield, at most irrigations. Reduced canopy mass in elevated [CO2] plants was attributed to suppressed lateral branch development due to an interactive effect of [CO2] and water stress on tuber sink strength. These results indicate that water stress predicted by climate change models will be mediated somewhat under [CO2] enrichment.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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