Enhancing feathering of one- and two-year-old nursery trees of ‘Granny Smith’ apple cultivar using benzyladenine and gibberellins

Synthetic cytokinin 6-benzyladenine (BA), when applied either alone or in combination with gibberellins (GA₄₊₇), plays an important role in the production of well-feathered apple nursery trees and in overcoming apical dominance.
This paper presents the effects of BA and BA+GA₄₊₇ on the feather formation on one- and two-year-old ‘knip-boom’ nursery trees of apple cultivar ‘Granny Smith’. In one-year-old trees, the solutions of BA and BA+GA₄₊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 the growing season.
In two-year-old ‘knip-boom’ trees application of 300 µL L^-1 BA, followed by 400 µL L^-1 of GA₄₊₇, were applied once, two or three times at 7-day intervals during growing season.
Our findings indicate that increasing the BA concentrations (250-450 µL L^-1) leads to a decrease in the total number of feathers.
On the other hand, GA₄₊₇ applications eliminate these negative effects.
In addition, in one-year-old trees BA+GA₄₊₇ at the rate of 450 µL L^-1 induced the occurrence of longer feathers compared to BA applied alone.
The positive influence of GA resulted in greater feather length.
This effect was especially pronounced in two-year-old trees when GA₄₊₇ was applied two or three times.
The treatments did not have any negative effects on tree height and trunk diameter.

III Balkan Symposium on Fruit Growing

M. Dorić, Z. Keserović, N. Magazin, B. Milić, M. Miodragović

6-benzyladenine, gibberellins, apple nursery trees, feathers, apical dominance

https://doi.org/10.17660/ActaHortic.2016.1139.86