Depression of Growth and Yield in Winter Barley Exposed to Sulphur Dioxide in the Field

SUMMARY A field exposure system designed for the controlled release of sulphur dioxide (SO2) was used in two contrasting seasons to expose commercial crops of winter bailey (Hordeum vulgare L.) to SO2 concentrations ranging from 40 to 200 ppb [parts per billion (109) by volume] above ambient. During winter and early spring, growth of the plants was depressed at high SO2 concentrations but later recovered; in spring and summer, low concentrations stimulated growth above that of controls, but there was no corresponding increase in grain yield. Yield depression is discussed in relation to SO2 concentration and dose.