24-Epibrassinolide improves some physiological disorders in pistachio cultivars

Abstract

The effect of 24-epibrassinolide foliar spray on some physiological disorders of pistachio cultivars was evaluated in two years. This factorial experiment was designed as a randomized complete block design with three replications. Factor A involved different pistachio cultivars and factor B involved the application time of hormone with four treatments including T1= bud swelling, T2= after full bloom, T3= T1 + T2, and T4= control. Different parameters were recorded. The application of hormone in both different stages caused the maximum fruit set percentage and minimum inflorescence bud and fruit abscission percentage in three sprayed cultivars. Despite of the highest percentage of inflorescence bud and fruit abscission in control treatment of cv. Kallehghoochi, the application of this hormone decreased these parameters in this cultivar in T3 treatment. Chlorophyll, protein, and proline contents of the leaves were increased in all brassinosteroide treatments, especially under two-stage application. Also, ion leakage and reduced sugar were decreased in treated leaves after using hormones. The effect of this hormone on antioxidant enzymes showed that all enzymes (CAT, SOD and APX) except POD were increased by the application of brassinosteroides. The loss of carbohydrate in one-year-old woods indicated the growth stimulating effect of this hormone. Thus, 24-epibrassinolide is a good suggestion to increase the quantity and quality of pistachio, especially in cv. Kallehghoochi.