Abstract: 【Objective】To obtain an optimized preharvest management mode to improve the longan fruit storability, the effects of disease control and nutrient management during fruit development on the characteristic quality and storability of longan fruit were explored. 【Method】A field-based orthogonal trial (₁₂ (4×3³)) was conducted with 12 combinations (labeled as BR1-BR12) using the cultivar Shixia as material, among which BR1 was the control (CK). Disease control (DCP), fertilization type (FT) and hormone regulation (HR) were used as factor A (FacA), factor B (FacB) and factor C (FacC) respectively. The fruit quality and mineral nutrient contents were determined at harvest time, and the storage effects for the fruit of 12 treatments stored at 5℃ were also observed regularly to screen the factors and levels with significant optimization effects.【Result】(1) Descriptive statistical analysis showed that the variation coefficients of 11 fruit quality and 20 mineral nutrition (in pericarp and aril) indexes ranged from 2.19% to 49.50% and from 5.14% to 77.43% respectively. Except for the organoleptic trait indicators including CDFS (cleanliness degree of fruit surface), RPTC (rust powder in the turtle cracks on the fruit surface) and ACD (aril crispy degree), the other indexes showed significant differences between treatments (P<0.01). (2) With the prolonging of the storage period, the MFR (mouldy fruit rate), EBI (endocarp browning index), ABI (aril breakdown index) of each treatment fruit increased, and the EFR (edible fruit rate) and storability decreased, and the difference between treatments was extremely significant (P<0.01). Moreover, the clustering results showed that BR11 and BR12 had the best storage effect with the lowest EBS (endocarp browning score), ABS (aril breakdown score) and MFRS (score of mildew fruit rate), and the highest EFRS (score of edible fruit rate) and CSES (score of comprehensive storability throughout the entire storage), and their storage life was about 40 days and about 15 days longer than the control (BR1). On the contrary, BR1and BR2 had the worst storability with about 25 days of storage life. (3) Correlation analysis showed that disease control (facA) was closely associated with EBS, ABS, MFRS, EFRS and CSES during the fruit storage (P<0.01), b^* value of fruit surface (FSb^*)  and ACD, total Zn and Mn contents in pericarp were closely related to fruit storage effects (P<0.01). Besides these, the contents of K, Ca, Mg mainly affected the SFM (single fruit mass), EPRF (edible portions rate in a fruit), TSS (content of total soluble solid substance) and RPTC of fruit, and the contents of Zn, Mn, B mainly affected CDFS and RPTC. (4) The estimated marginal means of each level of trial factors showed that, compared with no disease control (1-DCK) and young fruit stage (2-YS), disease control during the entire fruit period (4-EP) and expansion stage (3-ES) could significantly improve the FSb^*,FSC^* (C^* value of fruit surface, P<0.05) and CDFS (P<0.01), reduce the EBS, ABS and MFR, and ultimately improve the EFRS and CSES. Among the 4 kinds of disease control methods, the control effect of 4-EP was the best (P<0.01). Full nutrition fertilizer (3-FF) significantly improved the ACD, CDFS and CSES and reduced the MFRS, otherwise, hormone regulation (HR) did no obvious effect.【Conclusion】Scientific and reasonable disease control and nutrient management before harvest can significantly improve the characteristic quality and storability of longan fruit. It is recommended to optimize the comprehensive management mode during fruit development as “disease control throughout the entire fruit period + full nutrient fertilization”.

Key words: longan fruit, storability, characteristic quality, disease control, fertilization type