Study of temperature effects on growth and development of Pistachio

Climate change is an important trend that as an effect on the seasonal variation is happening. While that land and regional differences, which require specific methods for each region against damages from climate change to be adopted. This research carried out in the pistachio orchard to investigate the effects of temperature on growth and development factor since 2002 till 2009. Results showed that chilling requirements in kaleh ghoochi, Owhadi and Akbari cultivars were 600,800 and 1200 hours respectively. Although chilling more than the above mentioned amount was found effective on reducing of the time of bud booming. The results of correlation analysis showed that chilling requirement hours per year in 0 to 7 ◦c model had a positive and significant correlation with chilling requirement of December and March that correlation coefficient (R) was 0.863 and 0.72 respectively and in UTAH model had a positive and significant correlation with chilling requirement of November and January of which correlation coefficient (R) was 0.739 and 0.763 respectively. In experiments Appling chemical treatments to remove the chilling requirements of pistachio trees showed that soybean oil 6% and sodium benzoate 0.1% + potassium nitrate 0.5% + volk oil 5% comparing to control treatment significantly decreased ounce 1.38 and 1.01, blank percentage 3.5 and 2.28 and increased weight of 100 nuts 7.1 and 5.6 gr, fresh crop weight per tree 2.8 and 7 kg respectively. Critical temperature to caused tissue color change was identified as -4◦C at bud stage, -2 at blooming bud and +2 at flower. Decreasing temperature down to two more degrees (e.g. _6 at bud) could shift the damage into the irreversible and serious browning injury. Two cultivars did not show any significant differences as the point of critical temperatures and related injuries at each stage. Qazvini needed 2561.044 GDD and 138.5 days for total bearing period (flowering to harvest), and 623.363 GDD and 30 days for kernel filling period. Owhadi needed 2917.823 GDD and 160 days for total period. Testing of Fog machine comparing to control showed averagely increased 1.6 ºC temperature of fog, and relative humidity increased 10.3 % more in fog machine operated in compare to control. Study of Selective Inverted Sink (SIS) showed averagely both system in 1385 (first year of experiment) increased temperate of SIS operated in compare to control and in second years of ْ and averagely 2 C ْ minimum 0.3 ,ْ maximum 3.2 C temperature was increased in compare ْ experiment (1386) averagely 1.32 C to control. Results showed low-temperature development threshold in Study on temperature data were indicated in order to . ْ pistachio is 5.2 C 50% fruit ripening, Owhadi cultivar need 4280 degree-hours from March.