Abstract: Aiming at the problem of quality improvement of Ehima No. 28 hybrid citrus in high-quality cultivation, the effects of different fertilization treatments on fruit quality were studied. Two-year experiment results showed that the combination of compound fertilizer and organic fertilizer could effectively improve the Ehima No.28 fruit quality. Compared with the control, the application of 1 kg per plant potassium sulphate compound fertilizer （51%, N-P-K=17-17-17） and 2 kg per plant organic biological bacterial fertilizer showed that the soluble solids content significantly increased by 5.0%, the content of titratable acid significantly decreased by 22.1%, and the solid acid ratio of fruit juice raised to 20.0 that was significantly increased by 34.2%, while the single fruit weight significantly increased by 36.5%. The application of 1 kg per plant nitrate sulfur based compound fertilizers （44%, N-P-K=16-6-22） and 2 kg per plant organic biological bacterial fertilizer showed that the content of titratable acid significantly decreased by 18.2%, the solid acid ratio was raised to 18.6 that was significantly increased by 21.6%, however, there was no significant difference in single fruit weight. The two mixed collocation formulas could provide reference for scientific fertilization in field management, as well as improve the quality of Ehima No.28.

Key words: Ehima No.28, fertilizer, fruit quality