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Response of Potato Gas Exchange and Productivity to Phosphorus Deficiency and Carbon Dioxide Enrichment
Author(s) -
Fleisher David H.,
Wang Qinguo,
Timlin Dennis J.,
Chun JongAhn,
Reddy V. R.
Publication year - 2012
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2011.09.0526
Subject(s) - photosynthesis , carbon dioxide , stomatal conductance , transpiration , canopy , biology , dry matter , agronomy , fertilizer , phosphorus , human fertilization , water use efficiency , zoology , horticulture , cultivar , rubisco , phosphate , botany , chemistry , ecology , organic chemistry , biochemistry
The degree to which crops respond to atmospheric CO 2 enrichment may be influenced by nutrition. To determine the extent to which dry matter production, canopy and leaf photosynthesis, and transpiration are influenced by P and CO 2 , potatoes ( Solanum tuberosum L. cultivar Kennebec) were grown in outdoor soil–plant–atmosphere research (SPAR) chambers at two levels of CO 2 (400 or 800 μmol mol −1 ) and three levels of P fertilization. Total dry matter declined an average 42% between high and low P fertilizer and increased 13% in response to elevated CO 2 when averaged across the P treatments. This enhancement effect did not vary with level of P treatment. Leaf level photosynthetic rate was reduced 58% and stomatal conductance 43% between high and low P treatments. Biochemical model parameters for carboxylation rate, ribulose bisphosphate regeneration, and triose phosphate use were reduced by P deficiency but scarcely influenced by growth CO 2 . After tuber initiation, canopy assimilation rate increased under elevated CO 2 particularly at the middle levels of P fertilization, and diurnal canopy evapotranspiration showed a significant reduction in response to elevated CO 2 and declining P fertilizer. Lack of interactive effects between CO 2 and P on most measured responses suggests the effect of CO 2 enrichment on potato growth and assimilation is similar at each P‐treatment level; however, such effects may also be correlated with plant N status.