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Response of Net Carbon Exchange Rate of Soybean to Ozone at Different Stages of Growth and its Relation to Yield
Author(s) -
Miller Joseph E.,
Pursley Walter A.,
Vozzo Steven F.,
Heagle Allen S.
Publication year - 1991
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1991.00472425002000030011x
Subject(s) - yield (engineering) , photosynthesis , growing season , ozone , charcoal , zoology , chemistry , linear regression , glycine , crop , carbon fibers , horticulture , agronomy , mathematics , botany , biology , statistics , biochemistry , materials science , organic chemistry , amino acid , algorithm , composite number , metallurgy
High concentrations of ozone (O 3 ) occur episodically during the growing season, but the impacts of O 3 stress on photosynthesis and crop yield when O 3 episodes occur at various stages of growth are not known. Also, quantitative relationships between reduction of photosynthesis and yield suppresion by O 3 have not been established for most species. Field experiments with soybean [ Glycine max (Merr.) cv. Davis] were performed to determine the impact of O 3 exposure at different stages of plant development on net carbon exchange rate (NCER) and to establish the relationship between NCER and yield for different O 3 exposure periods. The growing season was divided into four quarters (Q1–Q4) of 31 d each for O 3 treatment. In each quarter, O 3 treatments in open‐top chambers were either charcoal‐filtered air (C) or nonfiltered air (N) to which O 3 was added to achieve approximately 100 nL L −1 O 3 (mean 7 h d −1 average for the quarter). The NCER was measured in eight O 3 treatments (CCCC, NNCC, CNCN, NCCN, CNNC, NCNC, CCNN, and NNNN) where each letter indicates the O 3 treatment for successive quarters. The NCER measurements during Q4 (R6–R7) provided the best relationship to yield in a linear regression model ( R 2 = 0.919). A significant relationship with yield was obtained also with NCER measurements from Q3 (R2–R5) ( R 2 = 0.626), whereas measurments during Q2 (V10‐R1) were poorly related to yield ( R 2 = 0.072). Good linear relationships of yield and NCER were found also when Q3 and Q4 or Q2, Q3, and Q4 data were combined. In all cases, however, Q4 data were essential to a good correlation between NCER and yield. It is likely that NCER measurements taken during Q4 correlated well with yield, because that was the period when the requirement for energy from photosynthesis is most critical for yield.