Abstract

Zinc (Zn²⁺) deficiency in pistachio is frequently reported. Zn²⁺ fertilisation can be an effective way of correcting Zn²⁺ deficiency thus enhance yield of pistachio grown in Zn deficient soils. The aim of this study was to determine the effects of Zn²⁺ fertilisation on the yield of pistachio grown under rainfed conditions. Four Zn²⁺ rates (0, 1, 2 and 4 g L^-1Zn²⁺) were applied at 15 day-intervals (before, during and after blossom). Zn fertilisation increased yield of pistachio from 5.4 kg tree^-1 at nill Zn²⁺ application to 6.2, 6.9 and 6.7 kg tree^-1 at 1, 2 and 4 g L^-1 Zn²⁺ application, respectively (15, 28 and 24% increase respectively). Zn²⁺ fertilisation also increased Zn²⁺ concentration of leaves from 9.2 mg kg^-1 DW in the control treatment to 9.0, 22.1 and 20.3 mg kg^-1 DW at 1, 2 and 4 g L^-1Zn²⁺ application, respectively (63, 140 and 121% increase, respectively). The results suggest that 2 g L^-1 Zn application would provide adequate Zn²⁺ nutrition in areas with similar edaphic and climate conditions to those in the present study.

Key words: Pistachio, zinc, zinc concentration, zinc deficiency, yield.