DIAGNOSIS OF FRUIT QUALITY AND MINERAL CONTENTS OF 'FUYU' PERSIMMON PRODUCED IN SOUTHERN BRAZIL

This study was carried out to characterize fruit quality and mineral contents of persimmon fruit (Diospyros kaki L.) cultivar ‘Fuyu’ produced in southern Brazil, in 2007 and 2008. Additionally, leaves harvested in the summer were assessed for mineral content. Fruits were harvested at commercial maturity from 65 commercial orchards, and assessed in terms of quality after 45 days of storage under modified atmosphere (at 0±0.8°C), followed by 7 days of shelf life (at 23°C). Fruits were treated with 1-MCP before storage to prevent chilling injury. At harvest, fruits had mean fresh mass of 223±42 g, soluble solids content (SSC) of 14.8±0.9%, flesh firmness of 60.9±5.8 N and skin color index of 4.2±0.8 (on a 3.5 to 8 scale). The contents of N, P, K, Ca, and Mg in the fruit were of 685±86, 291±86, 1611±195, 109±18, and 68±8 (mg kg^-1 of fresh mass), respectively. The contents of P, K, Ca, Mg, Mn and B in the leaves were similar to the values previously reported for different production areas, while the contents of Zn were lower, and N, Fe and Cu were higher. There was a negative correlation between fruit weight and flesh firmness and Ca content, as well as between fruit SSC and leaf N content. The incidence of fruits with black groove disorder (lined black dots along the skin) varied from 15 to 59% in 68.3% of the orchards. There was no significant correlation between incidence of black groove disorder and fruit weight, flesh firmness, skin color or SSC. However, the incidence of this disorder had a positive correlation with leaf N content. Fruit also exhibited a moderate incidence of small black spot disorder on the skin (an average incidence of 11.5%), which had a positive correlation with fruit skin color index, black groove and fruit K content.