Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2004
Publication Date: 11/10/2004
Citation: Flowers, M.D., Fiscus, E.L., Burkey, K.O., Booker, F.L. 2004. Ozone effects on snap bean photosynthesis and yield. ASA-CSSA-SSSA Annual Meeting Abstracts.
Technical Abstract: Tropospheric ozone levels are rising and are predicted to continue to increase. Past research has shown that chronic exposure to high ozone concentrations has detrimental effects on crop growth and yield. Therefore it is of great importance to understand the effects of ozone on photosynthesis, crop growth and yield. Our objective was to determine the effect of chronic ozone exposure on the gas exchange and yield of three lines of snap beans (Phaseolus vulgaris L.) with known differences in their tolerance to ozone. A replicated experiment was conducted in 2003 and 2004 at Raleigh, NC. Snap beans were grown in naturally lit environmentally controlled chambers with day/night temperatures of 28/23 C and relative humidities of 50% and 67%. Ozone treatments consisted of 12 hour average ozone concentrations of 0, 15, 30, and 60 ppb. Gas exchange measurements were taken weekly until harvest. Photosynthesis was significantly reduced by high ozone concentrations (60 ppb) in only the most susceptible snap bean line. However, yield was significantly reduced by the 60 ppb ozone treatment in all three lines. Surprisingly, small amounts of ozone (15 ppb) increased yield in two of the three snap bean lines compared to the control (0 ppb).