LODGING OF WINTER BARLEY (HORDEUM-VULGARE L) IN RELATION TO ITS DEGREE OF EXPOSURE TO SULFUR-DIOXIDE

Plots in a field crop of winter barley (Hordeum vulgare L. ev.‘Igri’) were exposed to SO2 concentrations of 50, 100 and 200 nl l−1 above ambient. During May 1984 the crop lodged owing to wind and heavy rain, and the severity of lodging was clearly related to the gas concentrations that the plants had experienced. Samples of stems from the experimental plots were tested to find how much force was needed to bend the basal internode. Stems of plants that had experienced SO2 elevations of 100 and 200 nl l−1 were weaker than those from control plots; stems of the plants exposed to 50 nl l−1 were the strongest of all. Investigation of stem anatomy showed that lodging resistance was correlated with stem anatomical attributes, and particularly with the thickness of pairs of contiguous walls of sclerenchyma cells. The differences in stem strength in the SO2 treatments probably arose from the effects of SO2 on plant growth earlier in the season. Copyright © 1990, Wiley Blackwell. All rights reserved