Advances in Tree Growth Control by Trunk Injection

Abstract

A study was made of new methods and chemicals for controlling regrowth in trees. As part of this research program a portable, air-powered equipment system was developed for injecting low volumes of concentrated aqueous chemical solutions into trees for sprout regrowth control. Using young seedlings in the greenhouse, 10 chemicals were screened for their effectiveness in controlling regrowth on 24 tree species. Laboratory studies were also conducted to determine the translocation and metabolic behavior of certain radio-labelled chemicals in young seedlings. Using the trunk injection technique, measurements of sprout regrowth were made on mature trees of several species during the period 1973-78. Of the growth regulators tested, daminozide, dikegulac and maleic hydrazide consistently caused reductions in sprout growth. In general, high concentrations were more effective in controlling regrowth than were low concentrations for equal volumes of the same chemical.