Influence of Wind Speed on the Sensitivity of Ryegrass to SO2

Abstract
The sensitivity of S23 Lolium perenne L. to 11 parts 10−8 SO2 was investigated at two different wind speeds. At the higher wind speed of 25 m min−8, SO2 caused significant reductions in leaf area, root/shoot ratio, and all dry weight fractions measured. At the lower wind speed of 10 m min−1 growth reductions were not found. The differences in sensitivity of plants to SO2 at different wind speeds is discussed in relation to boundary layer resistances of leaves. It is concluded that the sensitivity of a plant to a particular pollutant should no longer be measured in terms of only the concentration and length of exposure.