Preharvest Foliar Application of Ascorbic Acid Improves Growth, Yield, and Postharvest Quality of Broccoli ( Brassica oleracea var. italica)
Broccoli is a rich source of nutrients and bioactive compounds. Unfortunately, its shelf life is limited due to physicochemical losses and microbiological degradation. Therefore, the present research aimed to determine the efficacy of ascorbic acid (0, 100, 200, and 300 mg L −1 ) as a preharvest foliar spray for improving broccoli growth and morphological characteristics, yield, and postharvest storage quality. Among the used ascorbic acid concentrations, the 300 mg L −1 treatment was the most effective. Preharvest foliar application of ascorbic acid significantly increased the number of leaves (50%), head diameter (70%–80%), head fresh weight (27%), root length (28.6%), and root fresh and dry weights by 29% and 39%, respectively, compared with the control. The ascorbic acid application significantly improved the postharvest quality characteristics such as total soluble solids (TSS), ascorbic acid (60%), total phenolics (40%), and maintained the chlorophyll concentration (50% higher). Additionally, antioxidant enzymes, including superoxide dismutase (SOD; 120%), peroxidase (POD; 80%), and catalase (CAT; 150%), was markedly enhanced. Total flavonoids increased by 30%, while antioxidant activity improved by 60% compared with untreated plants. Moreover, ascorbic acid significantly reduced weight loss (50%), chlorophyll degradation, ion leakage (40%), and accumulation of hydrogen peroxide (35%) and malondialdehyde content (40%) in broccoli heads as compared to the control during storage. In conclusion, ascorbic acid preharvest treatment could be considered an effective approach to enhance the shelf life (6–8 days) and yield of broccoli than the control.