γ-Aminobutyric acid treatments of pomegranate trees increase crop yield and fruit quality at harvest

Abstract

γ-Aminobutyric (GABA) is a non-protein amino acid that has been reported to affect different plant developmental processes, including delay of fruit senescence and maintenance of quality when applied as postharvest treatment. In this experiment, GABA treatments (10, 50 and 100 mM) were applied by foliar spray to ‘Mollar de Elche’ pomegranate trees at three key points of fruit development. Results showed that GABA treatments increased crop yield in a dose-dependent way, this effect being due to a higher number of fruit harvested per tree. In addition, GABA treatments led to a deeper red colour of pomegranate skin and arils, the highest effects being observed for 100 mM dose. Total phenolic and total anthocyanin concentrations were also increased by GABA treatment, while other quality parameters such as total soluble solids, total acidity or firmness were not affected by treatments. Then, GABA preharvest treatment, applied at 100 mM, could be a useful tool to increase the economic profit of pomegranate crop, since higher yield and fruit with higher colour were obtained, which is an important quality parameter for this cultivar. In addition, aril total phenolics and anthocyanin content were increased, which would lead to enhance the antioxidant properties and health benefits for consumers.