This study was conducted at a private orchard in the Ekmale village of Duhok Governorate, Kurdistan Region, Iraq during growing season (2020) to evaluate the effect of foliar sprays of three concentrations of zinc (0, 750, and 1500 mg.L−1 ), three concentrations of copper (0, 100, and 200 mg.L−1 ) and three concentrations of iron (0, 150, and 300 mg.L−1 ) on leaf nutrient, fruit set, as well as yield and quality of 18- years old " Halebi " pistachio trees. The nutrition solutions were sprayed on trees at two times (bud swell stage and green tip stage). Based on the obtained results, fruit set percentage, yield, and leaf nutrient were significantly affected by foliar application of a zinc, copper and iron each alone. In combination, the triple interactions among 1500mg.L−1 zinc plus 200mg.L−1 copper and 300mg.L−1 iron was the most affected one which exceed significantly on the control treatment, Moreover, nutrient treatment had a significant effect on the percentage of blankness. In general, these results show that Zn, Cu and Fe fertilizers is necessary for obtaining better yield and fruit quality in " Halebi " pistachio trees.

The present study was conducted in 2016 to evaluate the efficacy of foliar spray of Aminoplasmal (A), Boron (B) and Zinc (Zn) on vegetative growth of pistachio trees (cv. 'Halaby'). Tests were done at a private orchard in the region of Ekmale province of Duhok governorate, Kurdistan Region, Iraq. Tests were designed as a 3×3×3 factorial experiment in a randomized complete block (RCBD) with three replications. Treatments tested in the study were three concentration levels of Aminoplasmal (0, 100 and 200ml.L-1); three concentration levels of Boron (0, 200, and 300mg.L-1) and three concentration levels of Zinc (0, 400, and 600mg.L-1). Treatments were consisted of 81 trees with three replicates and each replicate was contained 27 trees, foliar spraying of studied elements applied at two time, one in time of swollen bud and the other repeated after one month (23March and 27April 2016). Different trait, such as shoot lengths and diameters, leaf area, leaf dry weight, leaf chlorophyll content and number of leave per shoot were measured. Based on the results, the effects of spraying elements improved the vegetative characteristic. Results showed that Aminoplasmal at second and third levels had a significant effect on shoot lengths and diameters, leaf area, leaf dry weight as compared to control, on the other hand there were no significant differences between the level of Aminoplasmal 100 ml.L-1 and 200 ml.L-1 on shoot lengths and diameters, leaf area, leaf dry weight. In contrasts both of Boron at level 300mg.L-1 and Zinc at level 600mg.L-1 had a significant effect on total leaf chlorophyll content and number of leave per shoot. Referring to the triple interaction, the highest shoot length was obtained in the trees receiving 100 ml.L-1 Aminoplasmal  300 mg.L-1 Boron  600 mg.L-1 Zinc. Whereas the highest shoot diameter, Single leaf area, leaf dry weight, Total chlorophyll content, Number of leaves per shoot was obtained from the tree received Aminoplasmal200 ml.L-1 with Boron 300 mg.L-1 and 600 mg.L-1 Zinc.