ABSTRACT

Regulating the growth of fruit trees in the nursery is highly desirable. Foliar applications of triazole gibberellin biosynthesis inhibitors (GBIs) have been shown to control excessive vegetative growth of both mature, bearing trees and 1-year-old nursery-grown stock.

As an alternative to foliar applications, GBIs were applied directly to the bark of 1-year-old apple (Malus sylvestris Mill.), apricot (Prunus armeniaca L.), and cherry (Prunus sp.) trees using different adjuvants as carriers. Nine adjuvants were evaluated; three were found to be effective and nonphytotoxic. Results indicated stone fruit species may be more sensitive to triazole GBI trunk bark applications, but the effect was shorter lived than in pome fruit species.