Changes of physico-chemical quality and antioxidant activity at harvest and during storage in sugar apple subjected to drought stress

The effects of preharvest drought treatment on the expression of sugar apple (Annona squamosa L. 'Fai') fruit at harvest and during storage were studied. Changes of physico-chemical quality and antioxidant activity in sugar apples were analyzed at harvest and during storage at 15°C. Twelve trees were divided into two test groups. In the untreated control group, six sugar apple trees were irrigated during the experiment (30 L day^-1 tree^-1), and in drought stress group, six sugar apple trees were not watered for 30 days before harvesting the fruit. Sugar apple fruit were harvested at 110 days after full bloom. Thereafter, the fruit were stored at 15°C. The results showed that ascorbic acid and ABA concentrations, and SOD activity were increased in fruit peel from drought-treated trees at harvest. In contrast, the fruit size was reduced. In addition, drought stress also obviously activated antioxidant activity in the peel, and enhanced TSS in the flesh of sugar apple fruit during first four days of storage. These results suggest that preharvest drought treatment may improve eating quality in sugar apple through increase of sugar concentration in spite of the small fruit size.