Carbon Dioxide, Ozone and Soybean Diseases
Eastburn, D.M., Degennaro, M.M., DeLucia, E.H., Dermody, O. and McElrone, A.J. 2010. Elevated atmospheric carbon dioxide and ozone alter soybean diseases at SoyFACE. Global Change Biology 16: 320-330.
According to the five researchers, results indicated that "elevated CO2 alone or in combination with O3 significantly reduced downy mildew disease severity by 39-66% across the three years of the study." On the other hand, they say that "elevated CO2 alone or in combination with O3 significantly increased brown spot severity in all three years," but they add that "the increase was small in magnitude." Last of all, they say that "the atmospheric treatments had no effect on the incidence of SDS." Taken in their entirety, these several findings suggest that, on balance, elevated CO2 -- either by itself or in conjunction with elevated O3 -- should provide a net benefit to soybean productivity throughout the world, as the concentrations of these two atmospheric trace gases continue to rise in the years and decades to come.
Wrather, J.A., Anderson, T.R., Arsyad, D.M., Gai, J., Ploper, L.D., Porta-Puglia, A., Ram, H.H. and Yourinori, J.T. 1997. Soybean disease loss estimates for the top 10 soybean producing countries in 1994. Plant Disease 81: 107-110.