Impact of Ozone on Soybean Yield1
- L. W. Kress and
- J. E. Miller2
Field-grown soybeans [Glycine max (L.) Merr., cv. Corsoy] were exposed to O3 for 7 h daily (0900–1600 CST) for 56 d in open-top chambers. The air in the chambers was either charcoal-filtered or non-filtered, with various constant amounts of O3 added. The randomized block design incorporated four replicates of six treatments: no chamber (0.042 ppm O3 seasonal 7-h average); chamber with charcoal-filtered air (0.022 ppm O3); and chambers with non-filtered air plus added O3 to provide concentrations of 0.042, 0.064, 0.089, and 0.115 ppm. A linear reduction in seed weight per plant with increasing ozone dose (b (slope) = −87.18) was significant (P = 0.01), and yields were reduced 5, 23, 39, and 52% for the 0.042, 0.064, 0.089, and 0.115 ppm O3 treatments, respectively, compared with the 0.022 ppm treatment. Significant (P = 0.01) linear reductions were also noted for filled pods per plant (b = 184.4), seeds per filled pod (b = −0.9955), weight per seed (b = −0.3794), and percent oil content (b = −12.33). Significant (P = 0.01) linear increases were noted for unfilled pods per plant (b = 58.11) and percent protein content (b = 20.58). A comparison of the open plots with the nonfiltered air chamber plots provided with the same concentration of O3 revealed no significant chamber effects.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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