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Potato Gas Exchange Response to Drought Cycles under Elevated Carbon Dioxide
Author(s) -
Fleisher David H.,
Barnaby Jinyoung,
Sicher Richard,
Resop Jonathan P.,
Timlin D. J.,
Reddy V. R.
Publication year - 2014
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj14.0220
Subject(s) - water use efficiency , carbon dioxide , transpiration , stomatal conductance , dry matter , irrigation , photosynthesis , agronomy , chemistry , canopy , horticulture , soil water , zoology , botany , biology , ecology , organic chemistry
Elevated carbon dioxide (CO 2 ) influences photosynthesis ( A N ), transpiration (ET), and water use efficiency (WUE) for well‐watered potato ( Solanum tuberosum L.). Little is known regarding effects of short‐term drought and CO 2 . Two experiments, differing in the quantity of solar radiation, were conducted in soil‐plant‐atmosphere‐research chambers. Plants were grown at ambient (aCO 2 ) or twice‐ambient CO 2 (eCO 2 ) and received one of three irrigation treatments: no water stress (C), short‐term (11–16 d) water‐withholding during vegetative and post‐tuber initiation stages (VR), or post‐tuber initiation (R) only. Canopy conductance to CO 2 transfer (τ) and water vapor ( G v ), light use efficiency (α), daily A N , and ET decreased at the onset of each drought and were correlated with volumetric water content. The rate of decrease was similar for R and VR. G v declined more sharply than A N , resulting in higher WUE. Seasonal A N declined with the pattern of C > R > VR and was higher for eCO 2 C and R treatments. Seasonal WUE was higher for eCO 2 at all irrigation treatments. Total dry matter, harvest index, and leaf area were reduced ( p < 0.05) for droughted treatments and total dry matter and harvest index were also higher for eCO 2 VR pots. Relative responses to drought and CO 2 were similar among experiments, with greater magnitude of response under high solar radiation. Findings were similar to those reported under longer‐term water‐withholding studies, suggesting that interactions between CO 2 and drought on carbon assimilation and water use are conserved across production zones with varying radiation and rainfall patterns.