Relationship between dry matter content at harvest and maturity index and post-harvest quality of ‘Fuji’ apples

Abstract Two experiments were carried out to evaluate the relationship between dry matter content (DMC) and maturity index of ‘Fuji’ apple fruit sports (‘Mishima’, ‘Fuji Select’ and ‘Fuji Suprema’) during the final stage of fruit growth, and the relationship between DMC at harvest and the post-harvest fruit quality. Fruit were harvested from orchards of three regions (Caçador, São Joaquim and Vacaria), on two rootstocks (M9 and Marubakaido with M9 interstock). In experiment 1 (2014), fruit were periodically sampled beginning 83 days before the commercial harvest period. In experiment 2, fruit were harvested at optimum maturity for long-term storage and stored in air at 0.5 ºC (2014) or after optimum maturity for long-term storage and stored in controlled atmosphere at 0.7 ºC (2014 and 2015). Apple fruit maturity on the tree was characterized by decreased flesh firmness and increased starch index and soluble solids content (SS) and by a small change in DMC. DMC at harvest was correlated with flesh firmness and SS in one of two years, but DMC was not correlated with the incidence of disorders after storage. The results show that DMC at harvest is not suitable as a maturity index of ‘Fuji’ apples, and its use as a post-harvest quality predictor is not consistent between crop years