Effects of stage II and postharvest deficit irrigation on peach quality during maturation and after cold storage

Effects of regulated deficit irrigation (RDI) on the quality of a mid-late maturing peach (Prunus persica L Batsch cv Andross) were determined at commercial harvest as well as 1 week before (early pick-up) and after 1 week of cold storage. Respiration and ethylene evolution were measured during 96 h on fruits sampled at early pick-up and at harvest. Fruits from a well-watered irrigation treatment (Control) were compared with a treatment of RDI during stage II of fruit growth (RDI-SII) and with RDI applied postharvest (RDI-PH). A fourth treatment received a combination of deficit irrigation applied during stage II and postharvest (RDI-SII-PH). Higher soluble solids content (SSC) amd SSC/titratable acidity (TA) ratio for RDI-SII were already noted at early pick-up and these differences were enhanced after cold storage (RDI fruits having higher SSC, lower TA and higher SSC/TA ratio than Control fruits). This improvement in quality (high SSC/TA ratio) was also correlated with a more reddish colouration in the fruit skin. Moreover, ethylene production indicated different behaviour of the physiological evolution for fruits from the different treatments.