Efficacy assessment of pomegranate peel aqueous extract for brown rot (Monilinia spp.) disease control

Brown rot, caused by both fungal pathogens Monilinia laxa and M. fructigena, is considered as one of major preand postharvest pathogen of tree fruit. Therefore, this study aimed at evaluating the in vitro and in vivo ability of pomegranate peel aqueous extract (PGE) against both fungal pathogens causing brown rot. Results showed a significant antifungal activity on the in vitro mycelial growth of both fungi with inhibition rates ranging from 76.65 to 90%. In addition, obtained results highlighted a positive correlation between the concentration rates of PGE and the mycelial growth inhibition and the EC50 were 9.93 and 12.84 mg/ml for M. fructigena and M. laxa , respectively. Interestingly, spore germination of both pathogenic fungi was significantly reduced by PGE with EC50 of 7.7 and 8.58 mg/ml for M. fructigena and M. laxa . The germ tube elongation was significantly reduced by PGE. Furthermore, the in vivo trial on apple fruit showed promising results with disease severity of 21.03 and 42% respectively for M. laxa and M. fructigena at 50 mg/ml aqueous extract concentration. This concentration showed also the highest content of total phenolic (2737.44 mg GAE/L) and flavonoid (309 mg QE/L). It was concluded that the aqueous extract of pomegranate peels might be a sustainable alternative control strategy of brown rot. As a result, studies on mechanisms behind its effectiveness and practical use as formulated biofungicide product should be further considered in more details.