vanderKamp BJ, Karlman M, Witzell J
Relative frequency of bole and branch infection of lodgepole pine by western gall rust
Canadian Journal of Forest Research-Revue Canadienne De Recherche Forestiere: 1995 25:1962-1968
Tree height and number of western gall rust (caused by Endocronartium harknessii (J.P. Moore) Hirat.) bole and branch infections per living tree were recorded in three experimental 7-year-old lodgepole pine (Pinus contorta Dougl. ex Loud.) plantations located near Fort St. James, Mackenzie, and Fort St. John, B.C. An extra set of data for trees originating from north of 60 degrees N was also taken at Fort St. John. Each plantation consisted of 40 types of genetic material (i.e., different parentage and latitude of origin), while the extra set at Fort St. John consisted of 17 types of genetic material. The 4357 trees examined had an average of 1.81 gall rust infections per tree, and 49.1% of all trees were infected. Ninety percent of all infections originated in a single year (1990). The number of galls per unit target area declined with increasing height above ground. The percentage of galls located on the hole was 3.10, 10.53, 8.03, and 9.88% for the four populations, respectively. The number of western gall rust infections per tree was linearly related to tree height. The number of infections on boles did not vary with tree height, but the proportion of all infections located on the bole was linearly related to the reciprocal of tree height. The proportion of infections on the hole did not vary significantly with infection severity. Finally, the proportion of galls on the bole did not differ significantly between types of genetic material.
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