Abstract:

12-year-old Longanyou was used in this experiment as the material, the effects of different fertilization treatments on fruit yield and quality and the correlation between fruit color and luster and inherent quality were analyzed by measuring fruit yield, single fruit weight, fruit color and luster, fruit firmness and inherent quality. The results showed that (1) in 2017, the per plant yield of T1, T2 and T3 increased by 60.10%, 19.11% and 46.17%, respectively, compared with that of 2016, while the per plant yield of T4 decreased by 30.38%, and T2 had the highest per plant yield in both 2016 and 2017 (95.40 kg/plant and 113.63 kg/plant), indicating that fertilization had obvious effect on per plant yield; (2) the effect of fertilization on the color luster of pericarp was not significant, but the color of pulp was significantly affected, the pulp color of each fertilization treatment was orange red, and the color of T2 was darker than that of other treatments, while the color of CK was yellowish green; (3) fertilization significantly affected the pericarp, cysts and flesh firmness of Longanyou, especially on the fruit firmness of upper and lower layers of T2; (4) the content of invert sugar, total sugar, sugar acid ratio and vitamin C all reached the highest in the upper layer fruits of T2, the total soluble solids (13.07% and 13.07%) and solid acid ratio of T3 were the highest, and the content of titratable acidity in both T2 and T3 was relatively low, showing that T2 and T3 were beneficial to improve the inherent quality of fruit; (5) according to the analysis of the correlation between fruit color and fruit quality, it was found that each index of fruit color was closely related with the content of fructose. In conclusion, the amount of sugar may affect the fruit color of Longanyou.

Key words: Citrus grandis var. longanyou, fertilization, fruit yield, fruit quality, the color and luster of fruit