Influence of naphthalene acetic acid on aborted okra growth, bioactive compound and minerals

Abstract

The study was conducted to evaluate the effect of different concentrations of NAA (naphthalene acetic acid) on seedless okra production, vitamin C, carotenoids, flavonoids, antioxidants (DPPH), phenolic, and mineral content. The micro-syringe injection in flower stigma was an innovative method of application and was used in this experiment rather than spray as a common and traditional method. The flower stigma injection method was applied on the flower stigma after the anthesis of the flower of the okra plant using NAA at different concentrations. The lowest concentration (25 mg/l) of NAA greatly increased the pod setting compared to the higher concentrations and control. NAA application at 25 and 50 mg/l concentrations induced higher values of pod length, diameter, size, weight, ascorbic acid (vitamin C), and soluble solid content over the control. The chlorophyll content in leaves was affected significantly by different concentrations of NAA. It was found that 25 and 50 mg/l concentrations of NAA significantly increased chlorophyll content, fiber, moisture, flavonoid, carotenoid, antioxidant (DPPH), minerals and phenolic content compared to the other concentrations and control. In addition to that control and 25 mg/l concentrations of NAA, had increased the production of healthy seeds compared to the 50 and 100 mg/l. Moreover, 50 and 100mg/l of concentrations showed higher aborted seed (seedless) than the other concentration and control. Therefore, it seems that 25 mg/l is the best concentration for pod growth and development as well as 100mg/l is the best for seedless okra production.