Variation in productivity and fruit quality of the plum depending on rootstock

Despite Serbia being among the world’s largest producers of plums with about 5% of world production, seedlings of Myrobalan (Prunus cerasifera Ehrh.), characterized by a number of disadvantages, represent the most commonly used plum rootstock. Considering the intensification of plum production in the orchards of Serbia and other European countries, this study was aimed to assess the productivity and fruit quality of two plum cultivars (‘Čačanska Lepotica’ and ‘Čačanska Najbolja’) grafted on four different rootstocks (Myrobalan seedling, ‘Fereley’, ‘St. Julien A’ and ‘Pixy’) for two consecutive years (2017-2018). Cultivars ‘Čačanska Lepotica’ and ‘Čačanska Najbolja’ produced a similar average yield tree^‑1 (10.9 and 10.8 kg tree^‑1, respectively), while fruit weight, content of total phenols and antioxidant activity were significantly higher in ‘Čačanska Najbolja’ samples compared to ‘Čačanska Lepotica’, regardless rootstock. Yield tree^‑1 in plum grafted on Myrobalan seedling was higher compared to other rootstocks in both years, except in cultivar ‘Čačanska Najbolja’ in 2017, when the yield tree^‑1 was low in all studied rootstocks. Dwarf rootstock ‘Pixy’ showed the lowest yield tree^‑1 and induced high total phenols and antioxidant activity in fruit of cultivar ‘Čačanska Lepotica’ in both year of testing. However, in cultivar ‘Čačanska Najbolja’ there was no general trend in yield and fruit quality depending on rootstock. The medium vigor rootstocks ‘Fereley’ and ‘St. Julien A’ induced high values of yield tree^‑1 and content of total phenols in cultivar ‘Čačanska Lepotica’, although no significant differences were found with Myrobalan seedling as a rootstock. Owing to the high amounts of beneficial phytochemicals cultivar, ‘Čačanska Najbolja’ can be recommended for expansion in plum growing regions. Using semi-dwarf rootstocks ‘Fereley’ and ‘St. Julien A’, planting density can be increased, as well as yield and fruit quality, and facilitate application agricultural practices, such as pruning and harvesting.