Effects of Foliar Application of Boron and Calcium on Fruit set and Some Quantative and Qualitative Characteristics of Pistachio cv.  Owhadi'

Effects of foliar application of boron (B) and calcium (Ca) was investigated on fruit set and some quantity and quality characteristics of pistachio trees cv. ‘Owhadi’ in two consecutive seasons, 2011 and 2012. A factorial experiment was conducted in randomized complete block design whith nine treatments and three replicates at a pistachio orchard in Kusarriz region of Rafsanjan. Treatments include B as boric acid (0, 1000 and 2000 mg l 1) and Ca as calcium chlorid (0, 1 and 2%). Results of the first year showed that foliar application of 1000 mg l-l B increased the initial and final fruit set by 11 and 2l %, respectively, compared to controls. However, by application this level of B, some qualitative traits such as splitting rate, nut weight and rate of blankness significantly increased. In the second year, the highest rate of initial and final fruit set was obtained with application of 1000 mg l-1 boric acid. At the second year, concentration of Ca and B in the flower buds and leaves were increased by foliar spary of these elements, compared with controls. In general, the results of the present study showed that B application in concentration of 1000 mg l-1 after harvesting and swollen buds stages improved fruit set and some qualitative and quantitative characteristics of pistachio trees but foliar application of Ca reduced some of these parameters.