Fruit Characteristics of the Joy Peach Cultivars

Abstract

A trio of peach cultivars, Crimson Joy, Liberty Joy, and Rich Joy, have been recently released by the US Department of Agriculture breeding program at Byron, GA. They ripen at Byron in early to mid-June, late June to early July, and mid-July, respectively. Additional data on their fruit development are needed to understand the ripening process and optimize harvest timing. This study was designed to measure and compare characteristics of ripening fruit harvested weekly from the three Joy cultivars in two trial orchards. Fruit characteristics were significantly different among the three cultivars, the trial locations, and the harvest weeks. Difference in the five size-related characteristics (fruit weight, flesh weight, pit weight, and equatorial and polar diameters) and soluble solid content (SSC) were statistically significant among the three cultivars. ‘Crimson Joy’ had the smallest averages in the size-related characteristics and ‘Rich Joy’ fruit had the largest. ‘Liberty Joy’ had the firmest fruit and least juice volume and blush rating value at maturation. Trees in the commercial block produced larger fruit than those in the Byron research block. Differences among the harvests were statistically significant for all the fruit characteristics, suggesting that the peach fruit experienced dramatic changes as ripening progressed. The weights and diameters, juice volumes, and SSC continued to increase in the harvests although with reduced firmness. Correlation coefficients varied greatly between these fruit characteristics along with R2 and P values. The highest positive correlations were observed among fruit weight, equatorial diameter, polar diameter, and flesh weight. Pit weight was positively correlated with them to a lesser extent. Firmness showed substantial negative correlations with several characteristics, including three weights, two diameters, juice volume, SSC, and blush rating value. SSC and titratable acidity were also negatively correlated. The data confirmed that peach fruit continued to size while ripening and should be useful to determine appropriate harvest timing, which could differ for commercial packing vs. roadside sales.