Effect of Some Plant Growth Regulators on Seed Firmness, Quantitative and Qualitative Characteristics of Pomegranate (Punica granatum) cv. Yousefkhani

The present study was carried out to investigate the effects of some plant growth regulators on quantitative and qualitative characteristics of pomegranate (Punica granatum cv. Yousefkhani) with emphasis on their effect on reducing seed firmness. In this study, 10 and 20 mg L-1 kinetin, 10 and 40 mg L-1 gibberellic acid, and paclobutrazol, as an anti-gibberellin, at four concentrations (10, 50, 100, and 200 mg L-1) were sprayed four weeks after fruit set. Distilled water was applied as control. Results showed that foliar application of 10 and 20 mg L-1 kinetin increased fruit length and fruit weight, respectively. In contrary, small fruits with lower edible portion were produced after foliar application of 200 mg L-1. The highest percentage of edible portion was observed in fruits treated with 10 mg L-1 kinetin plus 10 mg L-1 gibberellic acid. Foliar application of plant growth regulators showed significant effects on seed firmness compared to control. The lowest seed firmness was observed using 100 mg L-1 paclobutrazol. Foliar application with various plant growth regulators also affected the chemical properties of the fruits. While the other treatments reduced total anthocyanin levels, treatment by paclobutrazol at a concentration of 100 mg L-1 preserved it.