Optimizing calcium application strategies to enhance fruit quality in tomato (Lycopersicon esculentum (L.) Mill)

This study investigates the effects of calcium application on tomato (Lycopersicon esculentum (L.) Mill) fruit quality, focusing on key physical and chemical attributes across vegetative and reproductive growth stages. Three calcium sources as Calnit (19% calcium), Winner (25% calcium with magnesium and boron), and Calmax (22.5% calcium) were applied as foliar sprays at early vegetative and reproductive stages. Results demonstrated that calcium supplementation enhanced fruit weight, circumference, firmness, total soluble solids (TSS), pH, vitamin C, and lycopene content, improving flavor, antioxidant levels, and shelf life. Winner, when applied at the beginning of the vegetative stage, significantly increased fruit weight to 26.88 ± 4.17 g, circumference to 16.68 ± 1.26 cm, and firmness to 3.94 ± 0.86 N/mm², while applications during the reproductive stage boosted TSS to 5.18 ± 0.33% and reduced Blossom End Rot (BER) incidence to 0.25 ± 0.50. Calmax, particularly effective for chemical properties, led to a higher pH (4.99 ± 0.10), vitamin C content (39.77 ± 1.78 mg/100 g), and lycopene concentration (0.94 ± 0.07 mg/100 g) when applied during the reproductive phase. These findings highlight the role of calcium in enhancing cellular integrity, supporting enzymatic activity, and facilitating nutrient transport, resulting in improved tomato growth, taste, and nutritional quality. This study underscores the importance of targeted calcium applications throughout growth stages for optimizing tomato fruit quality, offering valuable guidance for nutrient management practices in tomato cultivation.