Control of Stump Sprouting ofPopulus tremuloidesandP. grandidentataby Inoculation withChondrostereum purpureum

Chondrostereum purpureumwas applied to freshly cut trembling aspen (Populus tremuloides) and largetooth aspen (Populus grandidentata) stumps at three different application dates: late June, late August, and late September. Assessments conducted the following growing season revealed that the percentage of stumps with sprouts was significantly reduced (63%) by the application of the fungus. Although the application of the fungus also increased sprout mortality (39%), it affected neither the average number of sprouts per stump nor their maximum height. The percentage of stumps with sprouts was also found to vary significantly with the time of cutting. The late September cutting produced the greatest number of sprouts, whereas the late August cutting produced the fewest. The formulated fungus was not adversely affected by high temperatures, which reached 43°C on the surface of the inoculated stumps.