NITROGEN-FERTILIZATION AFFECTS QUALITY OF PEACH PUREE

Clingstone peach [Prunus persica (L.) Batsch cv. Allgold] trees were f ertilized once with 45 or 90 kg N/ha at budbreak or twice with 22.5 or 45 kg N/ha at budbreak and after harvest. ii nonfertilized control wa s included. Fruits from all treatments were made into puree, and objec tive and subjective qualities were evaluated. Puree from the N treatme nts and the control did not show significant differences in Color Diff erence Meter (CDM) 'L' and hue angle, pH, titratable acidity (TA), sol uble solids concentration (SSC), SSC:TA ratio, viscosity, ascorbic aci d, Ca, K, phenolic and nitrates concentration. Puree from the control and 22.,5 kg N/ha applied twice had significantly lower CDM 'a', 'b', and chroma values than from the other treatments. The split applicatio ns of N significantly reduced levers of Ca and ascorbic acid. N rate a nd number of applications interacted for 'a' and ii. When N was applie d twice at 22.5 kg . ha(-1), 'a' and K decreased, but this response wa s absent when N was applied twice at 45 kg . ha(-1). Puree from the no nfertilized control was rated lower by panelists for sensory quality t han that from the fertilized trees. Peach puree from trees fertilized once with 45 kg N/ha at budbreak had the best overall sensory quality.