ISSN:
1435-0653
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
3 ) in the troposphere can cause plant stress leading to foliar injury and suppressed growth and yield, whereas elevated CO2 generally enhances growth and yield. Numerous studies have been performed to determine effects of O3 and CO2 separately, but relatively few have been performed to determine if O3 can affect plant response to CO2 or vice verse. Open-top field chambers were used to determine if such interactions occur for cotton (Gossypium hirsutum L.), which is relatively sensitive to O3. Nitrogen nutrition is especially important in cotton production so N nutrition was included as an experimental factor. Plants were grown in 14-L pots at low, medium, and high soil N levels and exposed to three CO2 and two or three O3 treatments in all combinations during two seasons. The CO2 treatments were ambient (370 μL L-1) and two treatments with CO2 added for 24 h d-1 at approximately 1.5 and 2.0 times ambient. In 1995, the O3 treatments were charcoal filtered air (CF), and nonfiltered air (NF) with O3 added for 12 h d-1 (NF+). In 1996, a NF treatment was also included to represent ambient O3 conditions. The CF, NF, and NF+ treatments resulted in seasonal O3 concentrations of approximately 23, 51, and 75 nL L-1. Carbon dioxide enrichment generally stimulated growth and yield whereas O3 exposure suppressed growth and yield. Stimulation induced by CO2 increased as O3 stress increased. For example, in 1995 at medium N, the percentage increase in yield caused by doubling CO2 in CF air was 0%, but was 52% in NF+ air. Comparable values for 1996 were 23% in CF air and 140% in NF+ air. These interactions occurred for a range of soil N levels, and were probably caused by CO2-induced prevention of O3 stress. The results emphasize the need to consider O3× CO2 interactions to ensure correct interpretation of cause-effect relationships in CO2 enrichment studies with crops that are sensitive to O3.
Type of Medium:
Electronic Resource
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