EFFECTS OF FOLIAR APPLICATION OF SOME CARBOHYDRATES ON QUALITATIVE AND QUANTITATIVE TRAITS OF PISTACHIO NUTS CV. KALLEH-GHOOCHI

There is a potential negative effect on quality and yield pistachio nut due to the strong competition that may exist between vegetative growth and embryo development for carbohydrates. This experiment was conducted to determine the effect of foliar carbohydrate application at different timings on pistachio (Pistacia vera L.) cv. Kalleh-ghoochi nut quality and growth. A mixture of carbohydrates (3% Sucrose, 2% Glucose and 0.5% fungicide of copper oxychloride) were selected to study their effects on quantitative and qualitative traits of pistachio cv. Kalleh-ghoochi nuts. The experiment was carried out at Rafsanjan Pistachio Research Institute (RPRI) orchard during the 1997 growing season. Five treatments were arranged in a randomized complete block design (RCBD) with 3 replications. Treatments were applied during the stages of rapid embryo development kernel maturation both of which have large requirements for carbohydrates. The carbohydrate treatments were 1. applied at initiation of rapid endosperm growth; 2. applied at endosperm completion and initiation of rapid embryo growth; 3. applied at completion of embryo and cotyledon and digestion of endosperm; 4. applied at timings 1, 2 and 3; 5. untreated control. Results based on qualitative and quantitative trait measurements showed that the best time for carbohydrate application was during endosperm rapid growth. Carbohydrate application at this time improved nut quality by increasing shell dehiscence and decreasing the percentage of blank nut fruit abnormalities. In addition, results indicated that total leaf sugar was significantly increased compared with control when treated leaves were sampled after 4, 8 and 16 hours of treatments application. These results led to this conclusion that foliar carbohydrates were absorbed by pistachio leaves and improved nut quality.