Production of epicormic shoots on oak (Quercus robur):: effects of frequency and time of pruning

The effect of frequency and time of pruning on the population of epicormic shoots was investigated for two stands of oak (Quercus robur L.). Pruning frequencies consisted of eight permutations of pruning or not pruning in three successive years, comparisons were also made between pruning in four different months. The final pruning was in January 1994 and the last assessment was in early 1998. Pruning had a short-term effect on total number of epicormic shoots but this had mostly disappeared within the 7-year period. In addition pruning was shown to have little influence on the production of new epicormic shoots. No evidence was found to support varying the time of pruning to help control epicormic shoots. Different frequencies of pruning had inconsistent effects and none offered any guaranteed improvement over annual pruning, which must remain current advice for the long-term control of epicormic shoots.