Zinc oxide nanoparticles and bioinoculants on the postharvest quality of eggplant subjected to water deficit: Nano-oxido de zinco e bioinoculantes na qualidade pos-colheita da berinjela submetidas a daficit hidrico

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 ZnS[O.sub.4], 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. Key words: Solanum melongena, drought, fruit quality A berinjela (Solanum melongena) a amplamente cultivada. Apresenta toler ncia moderada ao dafice hidrico, mas sofre perdas de rendimento nas regi es aridas e semiaridas onde a cultivada. O objetivo deste estudo foi investigar a influencia das nanoparticulas de oxido de zinco (NPZnO), em associacao com bactarias promotoras de crescimento vegetal (BPCV), na qualidade pos-colheita de berinjela submetida a daficit hidrico. Foram estudadas duas percentagens de irrigacao referentes a evapotranspiracao potencial -ETo (50 e 100% de ETo) e cinco combinac es envolvendo NPZnO ou BPCV. Foram avaliados peso e numero de frutos comerciais e nao comerciais, di metro, comprimento, cor da casca, firmeza, acidez titulavel, solidos soluveis, SS/TA, vitamina C e acucares soluveis totais. Houve forte correlacao positiva entre peso de frutos comerciais, SS/TA, acucares soluveis totais, acidez titulavel, luminosidade e vitamina C nos tratamentos contendo ZnS[O.sub.4], NPZnO e BPCV. O daficit hidrico e as nanoparticulas contendo zinco, associadas ou nao a bactarias promotoras do crescimento das plantas, nao influenciaram o peso e o tamanho madio dos