effect of shoot girdling, fruit thinning and foliar application of urea, zinc sulfate and sucrose on yield, leaf chlorophyll content, photosynthesis rate and nut quantitative characteristics of pistachio cv. ‘ohadi’

in order to prevent of inflorescence bud abscission and reduce of alternate bearing in pistachio cv. ‘ohadi’ an experiment with 12 treatments including of girdling, fruit thinning, application of urea (0.5%), sucrose (3 and 5%) and their combination with urea, zinc sulfate (0.05 and 0.1% of pure zinc) and also their combination with urea in 3 replication and during 2 stages, was conducted in 2007 and 2008. the treatments were applied in two different stages of fruit growth and development including: 1- initiation of rapid growth of nut endosperm and 2- endosperm completion and initiation of rapid nut embryo growth. the results showed that girdling reduced inflorescence bud abscission, leaf chlorophyll content and photosynthesis rate significantly, but it didn't have any effect on qualitative and quantitative nut characteristics. the other treatments increased kernel weight and nut dehiscent and reduced ounce (no. of nuts per ounce), blankness, nut deformity and inflorescence bud abscission, but they didn't have any effect on early splitting. with the exception of zinc sulfate treatments, the others increased leaf chlorophyll content, meanwhile sucrose or combination of sucrose with urea reduced photosynthesis rate, but the other treatments increased it.