Ontario Hydro as a Potential user of Tree Growth Regulators

Abstract

Inconsistent results have been obtained after application tree growth regulators (TGRs). The most popular method of application (trunk injection) results in bark damage, wood staining, and bleeding injection holes, and the few economic analyses that have been reported suggest that only those trees that are expensive to trim and/or are trimmed on a short cycle are worth treating. Given the predominance of long trimming cycles in Ontario, the concern of the public over the use of pesticides, and the problems that arise after their application, the trunk injection of TGRs would not be a useful addition to the operational tree trimming program of Ontario Hydro.