Prediction of Butt Rot in Newly Regenerated Sprout Oak Stands

The incidence of decay in sprout oaks, contracted from the attached, decaying parent stumps, can be estimated from the proportion of sprouts that arise from the stumps an inch or more above the ground. Sprouts that arise lowest are least likely to become decayed. Five years after the sprout stands in this study were established following cutting, it was estimated that in 40 years, 32 percent of the new sprout trees would be butt-rotted. The stand was cut, however, at 32 years, by which time 24 percent of the trees were rotted. Measures that were effective in reducing the height of sprout origin, and so reducing decay in the newly-regenerating stand were: cutting close to the ground line, burning just prior to or following felling, and cutting the high-origin sprouts in subsequent thinnings. Season of cutting had no effect on decay incidence, but butt-rotted parent trees tended to produce sprouts that became rotted. Most of the rot was caused by Stereum gausapatum.