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Age Distribution of European Larch Canker in New Brunswick. D. P. Ostaff, Maritimes Forest Research Centre, Canadian Forestry Service, P.O. Box 4000, Fredericton, NB E3B 5P7. Plant Dis. 69:796-798. Accepted for publication 11 February 1985. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1985. DOI: 10.1094/PD-69-796.

The European larch canker, caused by Lachnellula willkommii, was found in 30% of the tamarack (Larix laricina) stands examined, affecting up to 100% of the trees. Counts of annual rings in cankered trees showed that the oldest canker, found near Saint John, was 25 yr old. Thus, the disease has been present in New Brunswick since at least 1958. Eighty-five percent of the stem cankers incepted on stems 9 yr of age and younger (range 217 yr). Incidence of the canker was greatest in areas with high rainfall, low snowfall, mean maximum temperatures greater than 0 C, and greatest number of degree days above 4.4 C from November to March.