Effect of Kaolin Application on Water Stress in Pistachio cv.  Ohadi'

Effects of kaolin applicati on were evaluated on water stress in pistachio cv. ‘Ohadi’. This experiment was conducted in one of research sites at the Pistachio Research Institute in Rafsanjan (Kerman province) in 2009. The results show that individual and interaction effects of all treatments were significant on nutrition absorption in leaves, although there was not a steady effect on all the elements. On the majority of the factors, control with 30 days irrigation period and lower kaolin application had more effect on nutrients absorbed by the leaves. Lower irrigation and upper concentration of kaolin application boosted soluble solids content. Increasing of prolin concentration was more impacted by the interaction of kaolin 2.5% and low irrigation treatments and also leaf area showed decreasing trend by single kaolin application, but in this regard, interaction of kaolin with low irrigation has boosting effect on this factor. Lower irrigation period decreased total nut production, blankness percentage, and increased fresh weight (nearly 50%), percentage of split nut, percentage of early split nut, percentage of irregular cracking nuts and ounce index. More kaolin concentration increased fresh weight, percentage of closed nut and lowering the total pistachio production, blankness and early split nut. Interaction effect caused increasing fresh weight, percentage of closed nut, ounce of nut, and decreased total pistachio production, spit nut, blankness and early split nut.