Performance of 'Sunburst' sweet cherry grafted on different rootstocks

The field performance of CAB 6P, CAB 11E, 'Colt', GM 9 ('Inmil'), GM 61/1 ('Damil'), GM 79 ('Camil'), Masto de Montanana 9 (MM 9), MaxMa 14, MaxMa 97 and Sainte Lucie GF 64 (SL 64) rootstocks grafted with one sweet cherry cultivar (P, avium 'Sunburst'), were compared for the first nine years after planting. The orchard was located on a calcareous clay-loam soil, which was level-basin irrigated. While no trees of CAB GP,'Colt','Damil', MM 9, and MaxMa 97 rootstocks died, most of the trees on 'Imnil' and 'Camil' did die. 'Damil' proved to be the most dwarfing and low-yielding rootstock, whilst 'Colt', MM 9 and CAB 6P were the most invigorating rootstocks, although differences with CAB 11E and SL 64 by the ninth year after planting were not significant. An intermediate level of vigour, shown on MaxMa rootstocks, could indicate a semi-dwarfing potential for these selections. In general, P. cerasus rootstocks (CAB 6P, CAB 11E and MM 9) promoted greater cumulative yields and better yield efficiency than the other rootstocks. Leaf mineral analysis of trees showed element concentrations close to the optimum for the trees grafted on P. cerasus rootstocks, and they were better than for trees on 'Damil' and 'Colt'. Leaf chlorophyll concentration, estimated by SPAD readings, was also generally higher for the trees on P. cerasus rootstocks. According to our results, the P. cerasus selections seem to be the best adapted rootstocks for cherry cultivars in heavy and calcareous soil conditions, under flood irrigation. However, they had the highest number of root suckers. The growing conditions were not favourable for the cherry rootstocks 'Camil','Damil' and 'Inmil'.