Abstract

GIBBS, J.N. and D.A. BURDEKIN. 1983. De-icing salt and crown damage to London plane. Arboric J 6: 227-237.

During the post-war period, crown dieback has occurred periodicaly in London plane planted in London and other British cities. Most affected trees are very close to roadsides but some damage has been recorded in parkland trees more than 45 m from roads. Recent investigations strongly suggest that much of the damage can be attributed to the effect of de-icing salt applied to roads during severe winters. The main symptom of this disorder is the death of foliage shortly after flushing, with some branches typically being more affected than others. Later in the summer, remaining leaves may develop marginal and inter-veinal scorching. Chloride levels in leaves from affected trees are between 1 and 3% of the dry weight, well above the 0.1–0.3% found in unaffected trees. In certain years quite severe disease in plane can be caused by the anthracnose fungus, Gnomonia platani, which can infect buds, shoots, and leaves. It seems likely that this fungus could have been responsible for the damage to trees growing remote from roadsides.

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