Rootstock effects on the growth, yield and fruit quality of sweet cherry cv. 'Newstar' in the growing conditions of the Region of Murcia

- Mariana 2624, Mayor and Adara were the most vigorous rootstocks and presented the highest yields with good fruit quality and the best agronomic performance.
- The best fruit quality corresponded to Pikú 3, which along with its low mortality values makes its use recommendable.
- Fruits from trees grafted on MaxMa 14 had the smallest size and the most intense coloration.
- The excessive vigour reduction in Gisela 5 resulted in a non-interesting rootstock for our growing conditions.
- Gisela 6, Pikú 1, SL 64 and Mayor rootstocks showed high mortality by root asphyxia, strongly related to drainage problems posed by heavy soils.

The influence of Adara, Gisela 5, Gisela 6, Mariana 2624, MaxMa 14, Mayor, Pikú 1, Pikú 3, Pikú 4 and Saint Lucie GF 64 rootstocks onto vigour, yield and fruit quality of 'Newstar' cultivar was studied during four years. The experiment was performed in Jumilla (Murcia, Spain), on a heavy and calcareous soil. Significant differences in parameters such as vigour, yield, fruit weight and size, soluble solids content, titratable acidity, skin colour and firmness were found among some rootstocks. Most of them achieved optimal coloration values that would have a high commercial acceptance. Gisela 6, Pikú 1, SL 64 and Mayor rootstocks showed high mortality by root asphyxia strongly related to drainage problems in heavy soils. Fruits from trees grafted on MaxMa 14 had the smallest size and the most intense coloration. The excessive vigour reduction in Gisela 5, together with a low yield and fruit quality, resulted in a non-interesting rootstock for our growing conditions. By contrast, Mariana 2624, Mayor and Adara were the most vigorous rootstocks and presented the highest yields with good fruit quality and the best agronomic performance, being their use advisable in warm Mediterranean regions such as the Region of Murcia. Although Pikú 3 induced low yield and obtained the highest values in fruit size, soluble solids content and fruit firmness, which, along with its low mortality, seem to recommend its introduction and use for producing high quality sweet cherries. The work demonstrates that rootstocks have been decisive in the vigour and yield of the grafted cultivar, as well as the size, acidity, colour and firmness of the fruit.