Punica granatum L. extract contributes to phytopathogens control and enhances Eruca vesicaria (L.) Cav. germination in vitro and in vivo

The study aimed to investigate antimicrobial activity of the hydroalcoholic crude extract from the fruit peel of Punica granatum (Pp) and punicalagin compound (Pg) on phytopathogenic bacterial isolates and its potential use as a sustainable alternative in treatment of vegetable seeds. The antimicrobial activity in vitro was tested by agar well diffusion assay and through viability tests in liquid medium. In vivo treatment with Pp was tested on Eruca vesicaria seeds infected with Xanthomonas campestris pv. campestris. Pp induced the formation of large inhibition zones to the growth of the tested pathogens (35.33 mm – 6.66 mm), with dose-dependent effect. Viability tests confirmed the antimicrobial activity of the Pp on X. campestris pv. campestris and P. carotovorum subsp. carotovorum with minimum inhibitory concentration (MIC) of 125 μg/mL. Punicalagin compound presented MIC of the 31.25 μg/mL. The seed treatment with Pp indicated control of pathogen-induced symptoms in seedlings of the E. vesicaria and positive effect in seed germination, emergence and in stomatal functionality. The results indicate strong potential of the extract from the fruit peel of P. granatum and Punicalagin for formulating botanical pesticides for plant disease control.