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.
Radivojević, D., Zivić, M., Milivojević, J., Oparnica, Č. and Veličković, M. (2016). Effect of 6-BA+GA(4+7) and nitrogen fertigation on feathering of 'Golden Reinders' apple nine-month-old nursery trees. Acta Hortic. 1139, 497-502
plant growth regulator, nitrogen fertilization, nursery tree quality, lateral branches