EFFECT OF ALMOND × PEACH HYBRID ROOTSTOCKS ON FRUIT QUALITY PARAMETERS AND YIELD CHARACTERISTICS OF PEACH CULTIVARS

The influence of six rootstocks (‘Adafuel’, ‘Adarcias’, ‘Cadaman’, ‘Felinem’ ‘Garnem’ and ‘GF 677’) on trunk cross-sectional area (TCSA), yield efficiency, and peach fruit quality parameters [Prunus persica (L.) Batsch] was evaluated. The six rootstocks were grafted with ‘Tebana’ peach and ‘Queen Giant’ nectarine cultivars during the summer of 1997, and trees were established in a trial during the winter of 1998-1999. The experiment was located in the Ebro Valley (Zaragoza, Spain), on a heavy and calcareous soil. The fruit quality parameters (fruit weight, firmness, soluble solids, pH, titratable acidity, and ripening index) and phytochemical constituents (vitamin C, phenol, flavonoid and anthocyanin contents, and relative antioxidant capacity) were determined. In addition, the most important sugars found in fruit flesh (sucrose, glucose, fructose and sorbitol) were analyzed by High Performance Liquid Chromatography (HPLC).
In the eleventh year after grafting, the lowest vigour was induced by ‘Adarcias’ rootstock with both varieties, although differences were not significant with ‘Cadaman’ when grafted with ‘Queen Giant’. For this cultivar, yield efficiency was higher on ‘Cadaman’ rootstock, although differences were not significant with ‘Felinem’. In the case of ‘Tebana, no significant differences among rootstocks were found. Regarding fruit quality parameters, the greatest soluble solids content (SSC) was recorded on ‘Adarcias’ and ‘Cadaman’ and the lowest on ‘GF 677’, while in the case of ‘Queen Giant’, no significant differences were found among all the other rootstocks. With this cultivar, the highest firmness was also induced by ‘Cadaman’ and the lowest by ‘GF 677’, whereas significant differences were not found among the other rootstocks. The highest titratable acidity (TA) was induced by ‘Cadaman’, although this did not differ significantly from ‘Adafuel’ when grafted with ‘Queen Giant’. The highest vitamin C content was shown on ‘Adarcias’ rootstock, and the lowest on ‘GF 677’, while no significant differences were found among all the other rootstocks when grafted with ‘Tebana’. Differences were also found in the antioxidant contents among rootstocks.