The influences of myrobalan rootstock and Saint Julian A interstock on some growing characteristics of five commercial cultivars of apricot

In order to overcome to some unfavorable environmental limitations, as well as achieving the low vigor apricot trees for extending intensive cultivations, a statistical study was conducted based on a randomized completely blocks design (RCBD) at the Sahand Horticultural Research Station since 2004 up to 2016. Experimental treatments were Consist of combination of scions from “Ordubad 90”, “Aybatan”, “Asgharabad”, “Germez-e-shahroud” and “Shastomi-yek” cultivars with seedling of myrobalan, seedling of apricot (as control) rootstocks and also, Saint Julian A interstock (grafted on seedling myrobalan). In this research, the main vegetative and generative characteristics were measured for assessment of scion/rootstock compatibility. The results showed significant differences among the performance of combinations for all studied traits (p≤0.05). The height of “Ordubad90” and “Asgharabad” cvs. on St. Julian A were 20 and 25 percent lesser than control, respectively. Full-blooming date of treatments was irregularly influenced by the type of rootstock but ripening date of their fruits followed aperfect pattern of corresponding control treatment. Comparison of diametric growth of rootstock and the height of combinations revealed a positive and significant correlation between these traits (r2 = 0.53). Based on results of this study, experimental apricot cvs. except Shastomi-yek were compatible with myrobalan rootstock and St. Julian A interstock. Deleterious local incompatibility symptoms on the combination of this cultivar and both mentioned rootstock and interstock were appeared from the first years of research that caused to their complete mortality. This result also revealed the necessity of precaution in recommendation of the widespread use of plum and prune species as apricot rootstock due to their incompatibilities in some cases.