Effect of 6-BA+GA₍₄₊₇₎ and nitrogen fertigation on feathering of ‘Golden Reinders’ apple nine-month-old nursery trees

The apple (Malus × domestica Borkh.) cultivar ‘Golden Reinders’ was used to study the effects of mixture of 6-BA and GA₍₄₊₇₎ (Promalin) and nitrogen fertigation to improve branching of nine-month-old nursery trees grafted on ‘M9’ rootstock.
Promalin was applied three times in June in weekly intervals, in concentrations of 0, 500, 1000, 1500 and 2000 mg L^-1 to the upper third of trees.
Nitrogen (N) was injected weekly at total amount of 50, 100, 150 and 200 kg ha^-1 for season.
Obtained results indicated that nursery trees without Promalin treatment were characterized by significantly lower trunk than with Promalin treatments.
Application of N through the system in increasing rates significantly contributed to higher values of trunk diameter.
Tree leaders were significantly longer in Promalin treatments only when amounts of applied N were above 100 kg ha^-1. However, N influence on height of nursery trees was not confirmed if they were not subjected to Promalin treatment.
Total number of feathers and the number of feathers >30 cm were simultaneously increasing with the increase of Promalin rates.
The same trend was observed with applying higher amounts of N. Significant interaction effect between Promalin and N confirmed in this study indicates that Promalin treatment has no effect on number of lateral branches without N application.
Increasing of Promalin concentrations above 1500 mg L^-1 had no significant influence on the number of lateral branches and number of feathers >30 cm, regardless of N amounts.

III Balkan Symposium on Fruit Growing

D. Radivojević, M. Zivić, J. Milivojević, Č. Oparnica, M. Veličković

plant growth regulator, nitrogen fertilization, nursery tree quality, lateral branches

https://doi.org/10.17660/ActaHortic.2016.1139.85