Abstract:

The typical shape of ‘Jingbaili’ pear is oblate, but improper pollinizer configuration and cultivation management often lead to deterioration of its fruit appearance quality. To enhance fruit marketability, this study investigated the regulation of fruit shape in ‘Jingbaili’ pear using plant growth regulators (PGRs). Based on an analysis of fruit growth patterns, different PGRs combinations (gibberellin, cytokinin, brassinosteroid, and their mixtures) and application timings (early and later fruit development stages) were applied. Their effects on fruit growth, development, and quality were systematically evaluated. Results showed a significant positive correlation between single fruit weight and both fruit longitudinal and transverse diameters. The rapid growth period of longitudinal diameter occurred between 34 to 74 days after full bloom, while that of transverse diameter was between 74 to 94 days after full bloom. Early-stage application of gibberellin or cytokinin prolonged the rapid growth period of longitudinal diameter, whereas brassinosteroid application did not alter the growth patterns of diameters or the fruit shape index. Application of PGRs at the later stage showed no significant effect on the growth patterns of diameters or the fruit shape index. PGR application at both stages reduced the fruit skewness index, with the gibberellin and cytokinin combination being the most effective. In conclusion, applying PGRs, especially the combination of gibberellin and cytokinin, during the early fruit development stage is more conducive to correcting the fruit shape of ‘Jingbaili’ pear.

Key words: ‘Jingbaili’ pear, fruit growth curve, fruit shape index, plant growth regulators, fruit shaping, gibberellin, cytokinin