Skip to main content
ARS Home » Southeast Area » Raleigh, North Carolina » Plant Science Research » Research » Publications at this Location » Publication #190358
Title: ELEVATED CARBON DIOXIDE AND OZONE EFFECTS IN PEANUT. I. GAS-EXCHANGE, BIOMASS, AND LEAF CHEMISTRY

Author
item Booker, Fitzgerald
item Burkey, Kent
item Pursley, Walter

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/9/2007
Publication Date: 6/15/2007
Citation: Booker, F.L., Burkey, K.O., Pursley, W.A. 2007. Elevated carbon dioxide and ozone effects in peanut. I. Gas-exchange, biomass, and leaf chemistry. Crop Science. 47:1475-1487.

Interpretive Summary: Current levels of the air pollutant, ozone, suppress agricultural production in most industrialized countries worldwide. Rising levels of carbon dioxide in the atmosphere, however, may protect plants from ozone damage, depending in part on the sensitivity of the crop. Elevated carbon dioxide tends to reduce ozone absorption and stimulate photosynthesis in many plants. In this experiment, we evaluated the interaction of elevated carbon dioxide and ozone on photosynthesis, plant growth, and leaf chemistry in peanut (Arachis hypogaea L.), an ozone-sensitive species, using open-top field chambers. Treatments were ambient, 1.5 and 2.0 times ambient carbon dioxide in combination with clean air, ambient ozone, and 1.5 times ambient ozone. Twice-ambient carbon dioxide levels increased seasonal net photosynthesis by 9 to 22% while lowering ozone uptake by 42 to 50%. In contrast, net photosynthesis was suppressed by 46% in the high ozone treatment. Plant biomass at harvest was increased by 12 to 15% by elevated carbon dioxide and suppressed 40% by added ozone. Leaf dry matter per unit leaf area and starch concentration were increased at elevated carbon dioxide and decreased by added ozone. Inhibitory effects of ozone on net photosynthesis, plant biomass, and leaf chemistry were countered by elevated carbon dioxide. Results of the experiment indicated that increasing concentrations of ozone can be expected to further inhibit net photosynthesis, leaf starch biosynthesis, and biomass production in peanut while expected increases in atmospheric carbon dioxide concentration should moderate but not nullify these responses.

Technical Abstract: The suppression of plant growth and yield by the air pollutant, ozone, can be ameliorated in many crops by elevated concentrations of atmospheric carbon dioxide. However, comparative growth and yield responses depend in part on concentration of the gases and sensitivity of the crop species and cultivar. In this experiment, we evaluated the interaction of elevated carbon dioxide and ozone on leaf gas-exchange, harvest biomass, and leaf chemistry in peanut (Arachis hypogaea L.), an ozone-sensitive crop, using open-top field chambers. Treatments were ambient carbon dioxide and carbon dioxide-enrichment of approximately 175 and 350 ppm in combination with charcoal-filtered air (23 ppb ozone), nonfiltered air (48 ppb ozone), and nonfiltered air plus ozone (75 ppb ozone). The addition of 350 ppm carbon dioxide increased seasonal net photosynthesis (A) by 9 to 22% while decreasing stomatal conductance (gs) by 42 to 50%. Net photosynthesis and gs were suppressed 46% and 18%, respectively, in the high ozone treatment. Harvest biomass was increased by 12 to 15% by elevated carbon dioxide and suppressed 40% by added ozone. Inhibitory effects of ozone on A and harvest biomass were countered by elevated carbon dioxide. Leaf mass per unit leaf area and starch concentration were increased at elevated carbon dioxide and decreased by added ozone. Chlorophyll concentrations were decreased by elevated carbon dioxide and added ozone. Results of the experiment indicated that increasing concentrations of tropospheric ozone can be expected to inhibit A, leaf starch biosynthesis, and biomass production in peanut while expected increases in atmospheric carbon dioxide concentration should moderate but not nullify these responses.