Influence of intensity and time of pomotechnical treatments on the characteristics of plum shoots

The issue of economically viable plum production implies the design and establishment of high-intensity training systems, that can enable quick fruiting and achieve high yield with satisfactory fruit quality. Intensive plum cultivation is possible in the spindle system, even when vigorous generative rootstocks (Prunus cerasifera Ehrh.) are used. For successful cultivation, it is necessary to apply various pomotechnical measures during the vegetation. The aim of this paper was to examine the effect of the intensity and time of new shoots heading treatment as part of regular summer pruning, on the shoot characteristics in the plum cultivars ‘Stanley’ and ‘Čačanska Lepotica’. This treatment aims to reduce strong vigor of upright new shoots. The research was performed during 2018 and 2019, on the ‘Stanley’ and ‘Čačanska Lepotica’ cultivars in a 10-year-old orchard. Lorette procedure was done during summer pruning in three different time periods during the vegetation (during the June) and heading was done above third and sixth node. The effects of new shoot heading on the characteristics of shoots at the end of vegetation such as the percentage of activated buds, the total length of newly formed shoots as well as the percentage of formed fruiting spurs, fully justify its application in the tested cultivars. Intensity and moment of application should be adjusted to the desired goal (vegetative development or reproductive potential).