Zinc oxide nanoparticles affect growth, photosynthetic pigments, proline content and bacterial and fungal diseases of tomato

Bacterial and fungal diseases of tomato caused severe yield losses and are important constrains in successful cultivation. Therefore, impact of zinc oxide nanoparticles (ZnO NPs) on growth of tomato (Solanum lycopersicum L.) and bacterial (Pseudomonas syringae pv. tomato, Xanthomonas campestris pv. vesicatoria, Pectobacterium carotovorum subsp. carotovorum and Ralstonia solanacearum) and fungal diseases (Fusarium oxysporum f. sp. lycopersici and Alternaria solani) were assessed. Maximum increase in plant growth (27.8–35.8% increase in shoot dry weight), photosynthetic pigments and proline content and reduction in disease indices (up to 1) were observed by foliar application of 0.20 mL−1 NPs followed by seed priming. Use of 0.10 mL−1 NPs was less effective. Scanning electron microscopy indicated adverse effect of NPs on pathogens. Higher accumulation of Zn occurred in leaves treated with NPs. Substantial management of above mentioned bacterial and fungal diseases may be obtained by foliar application of 0.20 mL−1 ZnO NPs.