Effects of Fe Foliar Spraying from Sulphate and Chelate Resources on Yield and Quality of Pistachio (Pistacia vera L. cv. Owhadi) Trees Fruit in Kerman Province

In pistachio growing areas due to high soil pH, nutrient uptake from soil is difficult. One of the ways to solve this problem is to spray the elements that it is applied after leaf analysis and deficiency detection of each element. In this study, the effects of foliar application of different concentrations of Fe from two sources of sulfate and chelate at two different time intervals on plant Fe concentration, yield and fruit quality were investigated. Current research was carried out on four one-hectare pistachio orchards with Owhadi (Fandoghi) cultivar including two in Rafsanjan, one in Kerman and one in Anar region from Kerman province. The study was carried out as a split plot statistical design with time interval of spraying at two levels (15 and 30 days) and sub factor of different concentrations (0, 1 and 2 Kg per 1000 L of iron sulfate; 0, 1.5 and 3 per 1000 L of Fe-EDTA) of two Fe resources (FeSO4 24%, Fe-EDTA 6%) with three replications including five trees in each replicate. The first spraying was conducted on fully expanded leaves near the end of April and the early stages of fruit growth. Fresh and dry weight of pistachio, blank nut percentage, nut-splitting percentage, 100 grains weight (oz. Of pistachio), early splitting percentage, length and diameter of current year branch, number of vegetative and floral buds, floral buds abscission and leaf Fe concentration were measured and  calculated. The results showed that spraying of iron fertilizers on pistachio trees deficient in this element had positive effects on pistachio quantity and quality. In total, three times Fe spraying from Fe-EDTA 6%, chelated source (made in Iran) with concentration of 1.5 Kg per 1000 L H2O at 15 or 30 days interval had the greatest effect on improving the quantity and quality of pistachio. According to the results of this experiment, spraying of above-mentioned treatment in Fe deficient pistachio orchards increased 72 kg / ha dry pistachio yield. In addition, blank nut, nut early splitting and floral buds abscission decreased 8, 1.3 and 7%, respectively. The percentage of nut splitting increased 5% and ounce of pistachio was reduced one unit.