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

摘要

The apple (Mains x 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 L1 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 indicatedthat 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 '. However, N influence on height of nursery trees was not confirmed if they were not subjected to Promalin treatment. Total number of feathers and thenumber 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 L1 had no significant influence on the number of lateral branches and number of feathers >30 cm, regardless of N amounts.