Zinc oxide nanoparticles and bioinoculants on the postharvest quality of eggplant subjected to water deficit

Abstract

Eggplant (Solanum melongena) is widely cultivated. It shows moderate tolerance to water deficit, but suffers yield losses in the arid and semi-arid regions where it is grown. The aim of this study was to investigate the influence of zinc oxide nanoparticles (NPZnO), in association with plant growth-promoting bacteria (PGPB), on the post-harvest quality of eggplant subjected to water deficit. Two irrigation percentages relative to potential evapotranspiration-ETo (50 and 100% ETo) and five combinations involving NPZnO or PGPB were studied. Number of commercial fruits per plant and weight of commercial fruits per plant, diameter, length, skin color, firmness, titratable acidity, soluble solids, SS/TA, vitamin C and total soluble sugars were evaluated. There was strong positive correlation between weight of commercial fruits per plant, SS/TA, total soluble sugars, titratable acidity, lightness and vitamin C in the treatments containing ZnSO₄, NPZnO and PGPB. Water deficit and nanoparticles containing zinc, associated or not with bacteria that promote plant growth, did not influence the weight and average size of the fruits and the post-harvest quality of the eggplant crop. Water deficit reduced the chromaticity and lightness of the skin color and the vitamin C content of eggplant.