Horticultural, leaf mineral and fruit quality traits of two 'Greengage' plum cultivars budded on plum based rootstocks in Mediterranean conditions

Field performance, leaf mineral content and fruit quality of two 'Greengage' plum cvs. 'R.C. Bavay' and S.C. GF 1119' budded on two plum based rootstocks (Ishtara and P.8-13) were studied in the network of an international European plum trial, promoted by the Fruit Research Station of the INRA of Bordeaux (France) and other European Research Centers. Trees were established in the winter of 1993-1994 in a heavy and calcareous soil with climate conditions typical of the Mediterranean area. Trees of 'R.C. GF 1119' were more vigorous than those from 'R.C. Bavay'. The highest yield was observed on the P.8-13 rootstock for both cultivars. In contrast, the highest cumulative yield and yield efficiency were induced by 'R.C. Bavay', independently of the rootstock. All trees budded on Ishtara survived well, whereas tree mortality was reported in trees budded on P.8-13 for each cultivar. Leaf chlorophyll content varied depending of the rootstock-scion combination. Most of the mineral nutrient concentrations were not affected by the rootstock -scion combination, with the exception of Mn, which was significantly lower on Ishtara for both cultivars. Overall, Ishtara resulted the best adapted rootstock to soil waterlogging and calcareous soil conditions showing a good tree survival and best leaf Fe mineral content. Further studies with plum varieties budded onto P.8-13 rootstock should be carried out to in order to recommend their use on soils with no waterlogging and/or associated diseases. Comparing the two cultivars, 'R.C. Bavay' showed better agronomic performance than 'R.C. GF 1119', in terms of cumulative yield and yield efficiency, and similar good fruit quality.