FIELD PERFORMANCE DIFFERENCES IN THREE APRICOT CULTIVARS PROPAGATED BY TISSUE CULTURE OR BY GRAFTING

A comparison between self-rooted trees, micropropagated in vitro, and trees grafted by traditional methods of the three apricot cultivars ‘Canino’, ‘Helena’ and ‘Lorna’ has been carried out in an experiment in the orchard. All ‘Helena’ and ‘Lorna’ trees were planted in 2000 whereas ‘Canino’ trees, self-rooted or grafted, were planted in 2002. In ‘Helena’, a significantly-higher total weight of fruits per tree was found in self-rooted trees, which may indicate a faster entry into production of the self-rooted trees. In ‘Lorna’, the total weight of fruits per tree was higher in self-rooted trees although differences were not significant. The trunk diameter, measured at 25 cm above the ground, was significantly greater in self-rooted trees of ‘Lorna’ while significant differences were not found for ‘Helena’ or ‘Canino’. Given that, at the beginning of the experiment, grafted trees were double the size of the self-rooted, this indicates that more-vigorous trees are obtained from in vitro culture.