Survival of Inonotus tomentosus in Spruce Stumps After Logging. B. M. Tkacz, USDA Forest Service, Southwestern Region, Forest Pest Management, Flagstaff, AZ 86004. F. A. Baker, Department of Forest Resources, Utah State University, Logan, UT 84322-5215. Plant Dis. 75:788-790. Accepted for publication 14 January 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0788.

Survival of Inonotus tomentosus was investigated by isolating the fungus from excavated stumps of blue spruce (Picea pungens) and Engelmann spruce (P. engelmannii) that had been harvested 9, 13, or 20 yr previously in southern Utah. The fungus was isolated from 62, 100, and 75% of 9-, 13-, and 20-yr-old stumps, respectively. The diameter of the smallest roots that yielded I. tomentosus ranged from 1.3 cm (9-yr-old stumps) to 2.5 cm (13- and 20-yr-old stumps). The maximum distances that I. tomentosus was found from the stumps were 3.4, 6.1, and 5.5 m for 9-, 13-, and 20-yr-old stumps, respectively. Isolates of I. tomentosus from stumps of all ages killed artificially inoculated Engelmann spruce seedlings.