EFFECT OF FRUIT-SET TIME ON THE QUALITY PERFORMANCE OF ANNONA CHERIMOLA MILL. FRUIT

The aim of this work was to analyze the differences between fruits obtained by different dates of fruit set and identify the proper fruit-set time that allows to obtain the optimum fruit quality in Annona cherimola cv Fino de Jete, planted in Southern Italy. Six fruit-set dates were selected from the first week of June to the second week of July. Fruits were sampled from October to November, when 1500 Growing Degree Days (DD) were accumulated; The DD were calculated using a base temperature of 12 °C. Fruit fresh weight (FW) and skin colour were measured. These parameters were measured also after storage, and in addition, the following parameters were measured: fruit shape (FS), pulp colour, pulp firmness, number of seeds, total soluble solids content (TSSC), titratable acidity (TA), ascorbic acid (AA), total polyphenol content (TPC), total antioxidant capacity (TAC) and fruit dry weight (DW). Moreover, fruit dry weight percentage, fruit fresh weight loss (FWL), and the seed index were calculated after storage. The fruit development period changed from 120 to 146 days with the fruitset date. The average seed number decreased with fruit set date. A strong correlation between fruit size and seed number occurred and also between the H/D ratio and number seed. FW decreased significantly from the third week of October to the first week of December and FS became progressively less regular in fruit coming from the 4th week of November to the 2nd week of December. From second to five sampling the AA was highest and similar. The lowest values of TAC were measured in the November and early December. The correlation between TAC and AA was stronger compared to TAC and TPC. All quality parameters of Annona cherimola fruit have reached the standards required by the market when 1500 DD have been accumulated from fruit-set. Eventually, the optimal period for fruit set ranged from end of June to the beginning of July.