Effects Of Bagging And Harvest Time On The Apple Fruit Quality

The objective of this article was to analyze the effects of bagging and harvest time on the apple quality and screen out the appropriate harvest time of bagged fruit. Starkrimson and Nagafu No.2 were used as the test material and non-bagged fruit as the control. Bags were used on at 50 and taken off at 136 days after full bloom(DAFB) for Starkrimson apple, and fruits were begun to harvest at 140 DAFB. Besides, bags were used on at 49 and taken off at 166 DAFB for Nagafu No.2 apple, and fruits were begun to harvest at 170 DAFB, and then picked every 5 days for each cultivated varieties. The fruit quality was immediately determined and fruit peel was observed by SEM(Scanning electron microscopy) after harvest. And the rest to measure the storage quality after 100 days stored at temperature 4℃ in the fridge. The results showed that:(1) The volume and single fruit mass of Starkrimson and Nagafu No.2 apple were no significant differences between bagged and unbagged fruits in the same harvest time. Bagging practice improved the brightness and coloration of apples. The volume, single fruit mass and coloration were increased, while the skinfinish were decreased in the bagged and unbagged fruits as the harvest time went on. Starkrimson fruit harvested at 155 DAFB, the production of bagged and non-bagged fruit was increased by 9.2 % and 8.53 % respectively compared with 140 DAFB. Nagafu No.2 apple fruit harvested at 185 DAFB, the production of bagged and non-bagged fruit was increased by 6.92 % and 6.58 % respectively compared with 170 DAFB.(2) The pulp density of Starkrimson and Nagafu No.2 apple have no significant difference between bagged and non-bagged fruit, while soluble sugar content of Starkrimson and Nagafu No.2 apple were decreased obviously by 0.93 % – 0.98 % and 0.85 % – 0.93 % respectively, the soluble solids content of Starkrimson and Nagafu No.2 apple were decreased obviously by 0.9 % – 0.99 % and 0.9 % – 0.94 % respectively. The practice of bagging also has reduced the titratable acid and Vc content of Starkrimson and Nagafu No.2 apple, and accelerated the rate of firmness decreasing, promoted the accumulation of anthocyanin. The soluble solids content and soluble sugar content were increased significantly, while the titratable acid was decreased significantly in the bagged and non-bagged Starkrimson and Nagafu No.2 fruit as the harvest time went on. The pulp density of Starkrimson and Red Fuji apples were no significant differences among harvest times.(3) For Starkrimson and Nagafu No.2 apple, the spot size and density of bagged fruit were less than non-bagged in the same harvest time, and the bagged fruit spot color was lighter than unbagged. Compared with non-bagged fruit, the thickness of peel was less, the epidermal cells arranged regularly and intercellular was smaller of bagged Starkrimson and Nagafu No.2 fruit. The microcracking area of bagged Starkrimson and Nagafu No.2 fruit was significantly more than unbagged by 2.37 % – 4.8 %, 3.56 % – 9.15 %, respectively. As the harvest time went on, the spot size and density were increased, the fruit spot color become darker, the epidermal cell layers and thickness of pericarp were increased, cracking angle of spot become bigger in the bagged and non-bagged Starkrimson and Nagafu No.2 fruit.(4) The storage quality of fruits has kept well for bagged Starkrimson picked at 150 DAFB and bagged Nagafu No.2 picked at 180 DAFB.As a consequence, it was concluded that the fresh-eating fruit of bagged Starkrimson and Nagafu No.2 should be respectively harvested at 155, 185 DAFB, and it was best for long-term storage fruit picked at about 150, 180 DAFB, respectively.