VIEW ARTICLE

Leaf Necrosis of Roadside Sugar Maple in Ontario in Relation to Elemental Composition of Soil and Leaves. R. Hall, Associate Professor, Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada; G. Hofstra(2), and G. P. Lumis(3). (2)Associate Professor, Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada; (3)Assistant Professor, Department of Horticultural Science, University of Guelph, Guelph, Ontario, Canada. Phytopathology 63:1426-1427. DOI: 10.1094/Phyto-63-1426.

Injury to leaves of sugar maple trees located 1 to 7.6 m from the pavement of Highway 6, Guelph, Ontario, was examined in relation to the concentrations of certain elements in leaves and soil. Leaves on the side of the tree nearer the pavement (front) were more injured (P=0.01) and contained higher concentrations of sodium and chloride (P=0.01) than those on the side of the tree further from the pavement (back). No significant differences between the front and back of trees were detected in foliar concentrations of nitrogen, phosphorus, or potassium. Sodium concentrations in soil (P=0.01) and conductivity of soil extract (P=0.05) were higher at the front of the tree than at the back. It is concluded that leaf injury was greater at the front of the tree due to the higher concentrations of sodium and chloride in foliage and of sodium in soil at the front of the tree.