EFFECTS OF CARBON DIOXIDE AND PHOSPHORUS SUPPLY ON POTATO DRY MATTER ALLOCATION AND CANOPY MORPHOLOGY

Abstract

□ Data on combined effects of elevated carbon dioxide concentration (CO₂) and phosphorus fertilization (P) on potato are scarce. Growth chamber studies (E1 and E2) that used three P and two CO₂ levels were conducted. Leaf, stem, tuber, and stolon dry matter increased with P. Lateral-stem production was sensitive to P with a minimum 2.5-fold increase in mass. Leaf length increased an average 20.2% in E1 and 38.2% in E2 and leaf area increased an average 336% in E1 and 470% in E2 across CO₂ levels. Tuber dry mass increased 22% in E1 and 38.2% in E2 in response to elevated CO₂ and total dry mass by 14.1 and 15.4%. Tissue P contents increased with P but were unaffected by CO₂. Effects of P on canopy branching were associated with plant N status. The studies suggest elevated CO₂ levels are unlikely to alter potato P requirements on a unit mass basis.

Keywords:

• potato
• phosphorus
• carbon dioxide
• climate change
• carbon allocation

ACKNOWLEDGMENTS

The authors would like to express their appreciation to the USDA-ARS Application Technology Research Unit at Toledo, Ohio, USA for providing the analysis of tissue P content. Thanks also go to Emily Morris and Jackson Fisher for their tireless help in collecting data, preparing samples and maintaining the growth chambers.

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