EFFECT OF ORGANIC FERTILIZATION, RIPENING STAGE AND STORAGE ON QUALITY OF FRUITS OF 'STARK REDGOLD' NECTARINE
The objectives of this experiment were to evaluate the effect of 1) application of compost, 2) ripening stage and 3) storage time on composition and antioxidant activity of nectarine fruit. The investigation was conducted in 2009 in an experimental orchard of Stark RedGold nectarine (Prunus persica var. nectarine) grafted on GF677 (peach (P. persica) × almond (P. amygdalus) hybrid rootstock that, since its plantation (2001), was subjected to the following experimental treatments: 1. control not fertilized; 2. mineral fertilization including N (70-130 kg ha-1 year-1) split in two applications at 40 days after full bloom (60%) and in September (40%); 3. compost (10 t dw ha-1 year-1) split as above. As a result of compost application, soil N and organic matter concentration were statistically increased. Samples of 20 fruit were collected one month (2 July) and one week (22 July) before commercial harvest, at commercial harvest (fruit ripening) (4 August), after 2 weeks at 6°C (cold storage, 17 August) and after 4 days at 24°C (shelf life, 21 August). At each sampling date fruit were weighed, lyophilised and milled to evaluate the concentration of organic acids, soluble sugars and antioxidant activity. At commercial harvest fruit yield, precocity index and, on 20 additional fruit, skin colour, fruit firmness, pH, acidity and soluble solid content (SSC) were determined. After cold storage and shelf life fruit firmness and SSC were determined. Nine years of soil application of different fertilizers did not modify sugar and soluble acid concentrations. Fruit firmness and acidity were increased by the application of compost as well as starch concentration that was higher, compared with control. Fruit sugar concentration increased while soluble acid and starch concentration decreased as ripening proceeded. Antioxidant activity was highest in unripe fruit and lowest after shelf life. In conclusion, the application of compost delayed fruit ripening; moreover anti¬oxidant activity decreased with the development of fruit ripening.
Baldi, E., Toselli, M., Marcolini, G., Quartieri , M., Marangoni, B. and Innocenti, A. (2012). EFFECT OF ORGANIC FERTILIZATION, RIPENING STAGE AND STORAGE ON QUALITY OF FRUITS OF 'STARK REDGOLD' NECTARINE. Acta Hortic. 933, 593-600
Prunus persica, compost, mineral fertilization, chemical composition, ripeness