Effect of different rootstocks on vegetative growth of Japanese and European plum cultivars in Southern Italy: Preliminary results

The preliminary results of a new rootstock trial for Japanese and European plum cultivars are reported. Two clonal Prunus cerasifera ('Myrobalan 29C' and 'MrS 2/5'), two Prunus domestica ('Penta' and 'Tetra') and the peach × almond 'GF 677' were tested in a warm and dry climate of Southern Italy where the plum industry is recently increasing, particularly for the Japanese type. 'GF 677' showed the most vigorous habit together with a higher production at the first bearing year in comparison with 'Myrobalan 29C', while the two P. domestica types resulted in very low vigour. This result was more evident and statistically significant with the Japanese plum cultivar, whereas very low differences were recorded in the European one. The evaluation of the results obtained, although still preliminary, suggests a deeper analysis of the planting systems adopted (i.e. trees spacing and pruning criteria) for Japanese and European plum orchards which may have to be significantly modified in relation to the vigour evidenced by the grafting combinations