MATURITY PATTERNS AND HARVEST INDEXES FOR GALA, GOLDEN DELICIOUS AND FUJI APPLES

The maturity patterns 'Gala','Golden Delicious' and 'Fuji' apples and the relationship to commercial harvest time were evaluated in Santa Ca tarina State, South Brazil, during 1985 to 1994. During the maturation period, linear and quadratic tendencies in the starch index and in th e total soluble solids increase, as well as in the firmness and acidit y reduction were observed. The changes of physico-chemical parameters started before the commercial picking period, indicating that they can be used as practical indices for predicting the harvest time. Starch indices between 3 and 5 for 'Gala' and 'Golden Delicious' and between 4 to 6 for 'Fuji' apples were associated with the commercial harvest d ates. At this period the largest acidity, TSS and firmness indices occ urred in 'Golden Delicious','Fuji' and 'Gala' apples, respectively. Th e seasonal variations for all parameters were largest for 'Gala' and l owest to 'Fuji' apples. In some cases, seasonal variations were larger than harvest dates effects. Apparently, the use of index Streif obtai ned by using firmness, TSS and starch indices is a reliable method to define the correct picking dates.