The influence of BA and BA+GA4+7 on formation of sylleptic shoots on one-year-old apple nursery trees

Abstract

This study presents the influence of BA (6-benzyladenine) and BA+GA4+7 (6-benzyladenine + gibberellic acids 4 and 7) on feathering of one-year-old apple trees of two cultivars Jonagold and Čadel. Different concentrations of BA (300, 600, 1,200 and 1,800 mg L-1) and BA+GA4+7 (500, 1,000, 1,500 and 2,000 mg L-1) were applied, and two treatments for both chemicals were performed. The first treatment was applied at 70-cm height of nursery trees and the second 2 weeks later. Comparison was performed in relation to untreated control. An application of BA and BA+GA4+7 did not affect both rootstock and nursery tree diameter at 10 cm above the grafting union. Nursery trees of cultivar Jonagold were not influenced by treatments applied, whereas in cultivar Čadel, the treatment with BA+GA4+7 decreased apical growth of nursery trees. The development of sylleptic shoots in both cultivars tested was influenced by the type of growth regulator and concentration applied. Treatment with BA at 300 mg L-1 concentration in both cultivars tested did not influence total length and number of sylleptic shoots, as well as the number of sylleptic shoots longer than 20 cm. The most positive influence on all studied parameters was observed on nursery trees treated with the concentration of 1,200 mg L-1 BA. The lowest concentration of BA+GA4+7 (500 mg L-1) caused the low feathering of both studied cultivars. The higher concentrations (1,000, 1,500 and 2,000 mg L-1) similarly increased the number and total length of sylleptic shoots of nursery trees.

U ovom radu je ispitivan uticaj BA (6-benziladenin) i BA+GA4+7 (6-benziladenin + giberelinska kiselina 4 i 7) na bočno grananje jednogodišnjih sadnica dve sorte jabuke Jonagold i Čadel. Primenjene su različite koncentracije BA (300, 600, 1.200 i 1.800 mg L-1) i BA+GA4+7 (500, 1.000, 1.500 i 2.000 mg L-1) pri čemu su kod oba hemijska jedinjenja tretmani izvedeni dva puta. Prvi tretman je izveden kada su sadnice bile visine 70 cm, a drugi tretman je izveden dve nedelje kasnije. Kontrola je bila bez tretiranja. Primena BA i BA+GA4+7 nije ispoljila uticaj na prečnik podloge i sadnice na visini od 10 cm iznad spojnog mesta. Kod sadnica sorte Jonagold nisu registrovane razlike u vršnom porastu pod uticajem primenjenih tretmana, dok je kod sorte Čadel tretman sa BA+GA4+7 uticao na smanjenje vršnog porasta sadnica. Ustanovljeno je da su tip hemijskog regulatora i primenjena koncentracija uticali na razvoj prevremenih grančica kod obe ispitivane sorte. Tretman sa BA u koncentraciji od 300 mg L-1 nije ispoljio uticaj na ukupnu dužinu i broj prevremenih grančica, kao i na broj prevremenih grančica dužih od 20 cm. Najpozitivniji uticaj na sve ispitivane parametre je zabeležen kod sadnica tretiranih sa BA u koncentraciji od 1.200 mg L-1. Najniža koncentracija BA+GA4+7 (500 mg L-1) je izazvala slabo grananje sadnica kod obe ispitivane sorte. Veće koncentracije (1.000, 1.500 i 2.000 mg L-1) su uslovile slično povećanje broja i ukupne dužine prevremenih grančica na sadnicama.