Performance of ‘sundrop’ apricot on 23 rootstocks

Abstract

The apricot cultivar ‘Sundrop’ (Prunus armeniaca L.) was planted on 23 different rootstocks at the Clyde Research Centre, Alexandra, New Zealand. Rootstock influence was assessed over a period of 9 years using the following criteria: tree survival, tree health, tree vigour (trunk crosssectional area), cumulative yield, cumulative yield efficiency, rootstock suckering, fruit quality (including bacterial marking on the fruit), and fruit size. Possible incompatibility was measured by stock/scion overgrowth and enlarged lenticels on the bark. The six most promising rootstocks could be grouped into three tree size categories: large, intermediate, and small. The best performing rootstocks which produced large trees were ‘Marianna 6.64’ and ‘Marianna GF 8/1’. Both rootstocks produced healthy, productive trees. However, trees on ‘Marianna GF 8/1’ suckered excessively from the roots, whereas those on ‘Marianna6.64’ did not. Three rootstocks—‘Golden Queen’, Prunus armeniaca ‘Zailisky’, and ‘Pixy’ produced the most promising intermediate-sized trees. ‘Golden Queen’ and ‘Pixy’ produced large-sized fruit, but in the instance of ‘Pixy’ the level of bacterial marking on the fruit and suckering from the roots was unacceptably high in two out of the three years in which data on these attributes were collected. ‘Zailisky’ produced trees with the best health score and the least bacterial marking on the fruit in two years out of three. ‘Marianna 9.52’ was the best rootstock of those tested which produced small, non-suckering, semi-dwarfing trees, with high yield efficiency and acceptable fruit quality. © 1994 The Royal Society of New Zealand.