γ-aminobutyric acid improves fruit yield and quality of ‘Le Conte’ pear in association with changes in antioxidant metabolism and phytohormone status

γ-Aminobutyric acid (GABA) is a non-protein amino acid involved in plant growth, stress responses, and metabolic regulation. Although exogenous GABA has been reported to improve fruit performance in some horticultural crops, information regarding its preharvest effects on fruit productivity, antioxidant-related parameters, and endogenous leaf phytohormone status in pear under open-field conditions remains limited. Therefore, this study evaluated the effects of foliar GABA applications (0, 50, and 100 mM) on fruit yield, physical and biochemical quality, antioxidant-related parameters, and leaf endogenous phytohormones of ‘Le Conte’ pear across two consecutive growing seasons. Foliar application of GABA significantly improved reproductive performance and fruit productivity. Compared with the untreated control, the 100 mM treatment increased initial fruit set by 73.7% and 69.2%, reduced fruit abscission by 33.1% and 32.9%, and increased fruit yield by 78.2% and 75.1% during the first and second seasons, respectively. GABA also increased fruit weight, firmness, fruit shape index, and flesh lightness. Treated fruits exhibited higher total soluble solids, total sugars, ascorbic acid, total amino acids, total phenolic content, total antioxidant capacity, and peroxidase activity, whereas polyphenol oxidase activity decreased. Foliar GABA application was also associated with increased leaf indole-3-acetic acid and decreased leaf abscisic acid concentrations. Foliar application of GABA, particularly at 100 mM, was associated with improved fruit productivity and quality of ‘Le Conte’ pear under field conditions. These responses coincided with changes in antioxidant-related parameters in fruit tissue and leaf IAA/ABA status during rapid fruit expansion. The findings indicate that foliar GABA application may improve pear fruit performance in association with these physiological changes.