*3.2.1 Effect of vinegar residue on blueberry growth*

There showed no significant differences in plant height, basal stem, single fruit weight, and fruit shape index among treatments (**Table 1**), but the aboveground dry weight of blueberry was improved significantly by vinegar residue. And the aboveground dry weight of VR1 increased 23.82% compared with CK. Root dry weight of VR1 and VR2 increased by 85.47 and 83.94%, respectively, and there was no significant difference in root dry weight between VR1 and VR2 treatments. The root-shoot ratio of plants treated with VR2 was the highest, 72.00% higher than CK, indicating that the application of vinegar residue significantly promoted the growth of blueberry roots. And 50% vinegar residue amount had the best effect on promoting blueberry growth.
