The effects of bud-scale removing and gibberellin (GA3) on dormancy break of apricot (P. armeniaca L.) vegetative buds

Effect of bud scale removal and different application rates of gibberellin (GA3) on bud break of dormant vegetative buds of two apricot cultivars was investigated. Shoot explants of ‘Jafari’ and ‘Rajabali’ cultivars were collected from one-year-old dormant branches and cultured in woody plant medium (WPM), supplemented with 2 mg L-1 of benzyl amino purine (BAP), 0.04 mg L-1 3-bndolebutyric acid (IBA). Treatments included three different concentrations of GA3 (4, 6, and 8 mg L -1), and removed and unremoved scale bud forms. The results indicated that none of the unremoved bud scales sprouted even when GA3 treatments were used (P≤0.01). The average of bud sprouting in removed scales buds was 62.77 %. The maximum bud sprouting (72.5 %) occurred in treatment with 8 mg L-1 of GA3 and removed bud scales. There was a significant difference between two apricot cultivars on vegetative dormant bud break percentage when scale removal of buds was done. The removed scale bud of ‘Jafari’ and ‘Rajabali’ cultivars sprouted 55.22 and 70.33 %, respectively. This study showed that the scales are probably containing inhibitory substances such as abscisic acid and by removing them, bud break will occur. Also, this method provides the possibility of in vitro culturing of apricot trees in non-growing seasons (winter).