Objective   To study the effect of spraying different foliar fertilizers on loquat fruit quality, and provide technical support for improving fruit quality in production and cultivation. o study the effect of Spraying Different Foliar Fertilizers on loquat fruit quality, and provide technical support for improving fruit quality in production and cultivation.

  Method  On 5-8-1 loquat plants, solutions of foliar fertilizers (i.e., 500-fold dilution of an amino acid, 200-fold dilution of a microbial fertilizer, 0.6% potassium dihydrogen phosphate, 0.1% ammonium molybdate, and sucrose at a 5 g·L⁻¹ application rate) and water as control were separately sprayed on the leaves 30 d before harvest. The individual weight, firmness, chromatic aberration, and contents of soluble solids, soluble sugars, titratable acid, vitamin C, and total phenols as well as antioxidant capacity of the loquat fruits at harvest were measured.

  Result  The spraying of foliar fertilizers increased the loquat fruit weight, soluble solids, soluble sugar, carotenoids, and sugar-acid ratio but reduced the titratable acid as compared with control. Except for the amino acid, all applications also significantly increased the Vc content. And aside from the potassium dihydrogen phosphate and ammonium molybdate treatments, the spraying enhanced the peel colorimetric a* and b*. The microbial fertilizer significant increased total phenols and flavonoids in the fruit, while the amino acid, potassium dihydrogen phosphate, ammonium molybdate, and microbial fertilizer, respectively, produced 20.92%, 17.44%, 17.10%, and 21.26% higher DPPH and 40.26%, 40.56%, 56.55%, and 68.05% more FRAP over control.

  Conclusion  The 5 foliar fertilizing agents tested in the study upgraded the loquat fruit quality to varying extends. Overall, the application using a 200-fold dilution of the microbial fertilizer was recommended.