The effects of zinc fertilisation on the yield of pistachio (Pistacia vera L.) grown under rainfed conditions

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-1 Zn2+) 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-1 Zn2+ 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.