Graft-compatibility of Rootpac rootstocks with nectarine and peach cultivars

Interspecific hybrids or clones from different Prunus species can be used as rootstocks for peaches. Recently, the Rootpac rootstocks have been released and begun to be used for peaches. Therefore, grafting aptitude and their compatibility with peach and nectarine cultivars should be examined. The aim of this study is to determine the graft-compatibility performance of different clonal Rootpac rootstocks with peach and nectarine cultivars. Graft unions of peaches and nectarines on Rootpac rootstocks were monitored at the Fruit Research Institute in Eğirdir, Isparta, Turkey. The peach cultivars ‘Monroe’, ‘Royal Glory’, ‘Q’Henry’, ‘Vista Rich’, ‘Cresthaven’ and the nectarine cultivar ‘Venus’ were T-budded on Rootpac-R, Rootpac-90, Rootpac-70, Rootpac-40 and Rootpac-20. The graft samples were evaluated with a microscope at 1, 4 and 12 months after budding. Cambial differentiation occurred after a callus bridge was formed between the two parts of the graft. The graft union and development was observed to be successful. Consequently, no evidence for histological incompatibility was found. In addition, no incompatibility visual symptoms (drying, chlorosis on the leaves, premature death of the trees, marked difference in the growth rate or vigor of scion and stock, over growth at, above or below the graft union, etc.) were observed until the third vegetative season of the budded trees.