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Soybeans are sensitive to certain air pollutants, especially ozone and sulfur dioxide. The degree of sensitivity to these two pollutants depends on the variety and the specific environmental condition. The symptoms vary somewhat and can be easily confused with other stresses that limit plant growth, such as nutritional imbalances, drought and temperature extremes. Ozone injury is similar to sunburn injury to the leaf and may include a grayish cast to the leaf. The symptom for sulfur dioxide injure can be severe enough to cause a complete bleaching of interveinal tissue, but normally the problem is seen as white interveinal flaking. |