Effects Of Pre-harvest Bagging On Fruit Growth And Development, Fruit Quality And Post-harvest Storability Of 'Lidongben' Longan Fruit

Fruit of'Lidongben'longan (Dimocarpus longana Lour. cv. Lidongben), a late mature cultivar in Fujian Province of China, was used. Effects of pre-harvest bagging at 80, 95 and 110 days after full bloom on fruit growth and development, appearance quality and pulp internal quality of longan fruit,and post-harvest storability of longan fruit were investigated in this paper. The results were as follows:1. Early pre-harvest bagging yielded a high rate of fruit-dropping. Application of pre-harvest bagging increased fruit vertical diameter, fruit horizontal diameter, single fruit weight of longan. Fruit pre-harvest bagging could obviously improve appearance quality and pulp internal quality of longan fruit. Fruit pre-harvest bagging increased contents of chlorophyll, carotenoids, anthocyanins and flavonoids in pericarp and contents of total soluble solids, total sugars, vitamin C and soluble protein in pulp of longan fruit, and decreased content of titratable acidity in longan fruit pulp.2. Fruit pre-harvest bagging increased contents of phenolics (including anthocyanin, flavonoid and total phenolics) and activity of peroxidase (POD) in pericarp of longan fruit, which were closely related to pericarp browning of longan fruit, hence, fruit pre-harvest bagging promoted the occurrence of pericarp browning during longan fruit storage. Meanwhile, fruit pre-harvest bagging could obviously increased the developments of aril breakdown and post-harvest diseases of longan fruit which resulted in reducing fruit storability and shortening storage life of longan fruit.From the results it can be seen that fruit pre-harvest bagging could obviously improve appearance quality and pulp nutritional quality of'Lidongben'longan fruit, and the results suggested that the optimum pre-harvest bagging period of'Lidongben'longan fruit was 110 days after full bloom, i.e., about 1 month before harvest. Whereas, fruit pre-harvest bagging could decrease fruit storability and shortening storage life of longan fruit.