Does moringa leaf extract have preservative effect improving the longevity and postharvest quality of gladiolus cut spikes?

Gladiolus is one of the most popular cut flower crops that manifest postharvest problems of rapidly losing the aesthetic value and short vase life that cause quality loss. The study was therefore carried out to investigate whether moringa leaf extract (MLE) has the ability to act as postharvest preservative solution to improve the quality and longevity of gladiolus spikes. Gladiolus spikes were subjected to various concentrations (0, 1, 2, 3, 4%) of MLE in vase solution. All MLE concentrations significantly extended the vase life and resulted in 10 days longer than the control when 3% MLE was applied. MLE treatment also improved the floret opening and reduced the weight loss of cut spikes. The relative water content (RWC), chlorophyll content, and membrane stability were considerably maintained while the microbial growth was suppressed in vase solution by MLE treatments. Also, malondialdehyde (MDA) and H2O2 production was significantly suppressed by MLE treatments. MLE significantly increased the total phenolics and the activities of antioxidant enzymes (CAT and PDX) in the florets. These ameliorative effects of MLE were more pronounced by the concentration 3% and further higher level causes no improvement in cut gladiolus spike longevity and quality. It is concluded that MLE showed these effects via alleviation the oxidative stress induced in the cut spike, maintaining photosynthetic pigments and water relations. We recommend MLE to be applied as a potential and promising eco-friendly alternative to common chemicals used in preservative solutions of cut flowers. MLE could also be commercialized as a novel floral preservative for future floral industry application.