ENHANCING FEATHERING OF ONE-YEAR-OLD GALA AND JONAGOLD APPLE TREES THROUGH APPLICATION OF 6-BENZYLAMINOPURINE AND GIBBERELLINS

B. Milic, M. Doric, Z. Keserovic, N. Magazin

Abstract: In apple, synthetic cytokinin 6-benzylaminopurine (BA), either alone or combined with gibberellins 4+7 (GA4+7), plays an important role in overcoming apical dominance and in the production of well-feathered apple nursery trees. The solutions of BA and BA+GA 4+7 corresponding to the concentrations of 250, 350 and 450 µl l-1 of active ingredient (BA) were applied three times at 7-day intervals during vegetative period. Feather formation is strongly influenced by type and concentration of plant growth regulators. Increasing concentrations of BA and BA+GA4+7 led to a greater number of feathers, increased feather length, and expanded branching zone. Applied in combination with GA4+7, BA has stronger positive effect on total feather number, feather length, branching zone and tree height, than when applied alone. Compared to BA+GA4+7, BA has a stronger effect on the growth rate of the shoot, resulting in a greater feather angle and a lower tree height, which can be eliminated by addition of GA 4+7. The treatments also had different effects on trunk diameter. In Gala, a minor adverse effect of BA on trunk diameter was noted, whereas it was positive in Jonagold.

Keywords: apical dominance; auxins; feathers; Malus domestica; nursery trees

Date published: 2017-09-14