Interaction Effect of Boron and Gibberellic Acid on Percentage of Fruit Loss of Two Pistachio Cultivars in Qazvin

Qazvin is one of the most important areas of pistachio production in Iran. The high percentage of fruit loss per pistachio trees is one of major problems in pistachio trees. Boron is a nutrient that improves pollen germination and the development of the pollen tube. Gibberellic acid is a hormone that improves fruit growthand percentage. A complete randomized block factorial expriment with three replication and three factors including two different cultivars (Fandogi and Qazvini), three amounts of foliar application of boron fertilizer (0, 3 and 5 per thousand) and three amounts of foliar application of gibberellic acid hormone (0, 2500 and 5000 mg/l) was carried out in one of the pistachio orchards of Boinzahra city of Qazvin. Foliar application of boron and gibberellic acid in two times (bud swelling and after harvesting) was carried out. The percentage of fruit loss after harvesting was determined.The results showed that foliar application of boron reduced percentage of fruit loss at% 1 level of significance. As well as foliar application of gibberellic acid reduced percentage of fruit loss at% 1 level of significance. The intraction effect of boron and gibberellic acid reduced significantly percentage of fruit loss at% 1 level.