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ARS Home » Research » Publications at this Location » Publication #82758
Title: GROWTH AND DEVELOPMENT OF SNAP BEAN AS INFLUENCED BY ELEVATED CARBON DIOXIDE AND OZONE

Author
item Reinert, Richard
item EASON, GWEN - NCSU PLANT PATHOLOGY DEPT
item BARTON, JEFFORY - NCSU PLANT PATHOLOGY DEPT

Submitted to: Environmental Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Carbon dioxide levels in the atmosphere have increased in recent years and it is predicted that concentrations will double sometime in the next century. Elevated carbon dioxide in the air has been shown to be beneficial to plants by stimulating growth and increasing yield. Ozone concentrations in the lower atmosphere (troposphere) have also increased in the last 50 years. Elevated tropospheric ozone visibly injures plant leaves and suppresses growth and yield. Little is known about the combined effects of carbon dioxide and ozone at elevated concentrations. In greenhouse studies, bean plants were exposed to various concentrations of carbon dioxide and ozone in combinations. Carbon dioxide concentrations ranged from ambient to a near doubling of ambient and ozone concentrations ranged from below to above ambient. We found that carbon dioxide was beneficial to bean growth and yield, and it limited the inhibition of growth caused by ozone. The nature of the interaction of the two gases depended on their individual concentrations. These findings indicate that accurate projections of effects of increasing carbon dioxide concentrations on agricultural production requires an understanding of interactions with other components of the atmosphere.

Technical Abstract: 'Oregon 91' blue lake snap bean were exposed to five CO2 treatments [375 (ambient), 450, 525, 600, or 675 umol mol-1] in combination with O3 (0 or 80 nmol mol-). Growth was evaluated following 4 wk and 7 wk of exposure. Carbon dioxide enrichment averaging over O3 concentrations significantly increased leaf, stem, root and total vegetative plant biomass at each harvest date. increases of 56%, 36%, 40%, and 47% for leaf, stem, root, and total vegetative plant biomass were observed after exposure to 675 ul l-1 CO2 for 4 wk compared with exposure to ambient CO2. Following 7 wk of exposure, CO2 enrichment averaged over O3 significanty increased leaf, stem, root, and total plant biomass including mature dry pod biomass by 20%, 17%, 48%, and 46% after exposure to 675 ul l-1 CO2 for 7 wk compared with exposure to ambient CO2. Exposure to O3 for 4 wk suppressed the vegetative biomass of each variable, except stem dry weight. Following 7 wk of exposure, there were no significant O3 effects on vegetative bean biomass except for root dry weight. Mature pod biomass was not affected significantly by O3. There were no significant interactions between CO2 and O3 on biomass at either harvest. Carbon dioxide enrichment limited the detrimental effects of O3 on vegetative biomass in both growth stages and on mature pod dry weight.