Growth, Development, Biochemical Changes and Harvesting Index of Mango (Mangifera indica L.) cv. Tongdum

บทคัดย่อ

The study on growth and development, biochemical changes and harvesting index of mango (Mangifera indica L.) cv. Tongdum grown at Pak Chong, Nakorn Rajsima was carried out at the Laboratory of Horticulture Department, Faculty of Agriculture, Kasetsart University during November 1984 to October 1986. The results showed that the growth pattern of seed and fruit followed the simple sigmoidal curve. The period from 50% bloom. The mature fruit weighed 270-343 g. Titratable acidity (TA) was high in the first two weeks and decreased thereafter. Total soluble solids (TSS) content was very high at the early stage of fruit development and decreased to the low level in the tenth week after that period. The TSS content gradually increased when the fruit approached maturity. Vitamin C content increased from the first two weeks and reached the maximal level in the fourth week. Thereafter the content decreased again. Reducing sugars and total nonstructural carbohydrates contents were high in the first three weeks and the amount increased rapidly after the tenth week till harvest. Reducing sugars content gradually after the thirteenth week. The mature fruit harvested at about 97-106 days had the specific gravity higher than 1.00. Heat units, fruit firmness and TSS/TA ranged from 778.80-873.65 centigrade degree days (CDD), 19.21-19.87 kg/cm² and 7.28-8.33 respectively. When the fruit was ripened, fruit firmness ranges 1.18-1.32 kg/cm² whereas TSS/TA ratio ranged from 42.79-49.48 β-carotene content was between 4,935-6,109 µg/100g fresh weight and the flesh color was grey-orange 163-168 group B-C. Record of fruit age from 50% bloom to harvest, specific gravity and heat unit can be recommended as harvesting indices of this Tongdum cultivar.