Evaluation of the Effect of Potassium Fertigation on Quantitative and Qualitative Characteristics of Two Pistachio Cultivars of Ahmad Aghaei and Kaleghoochi

Inorder to investigate the role of potassium in quantitative and qualitative characteristics of pistachios cultivars "Ahmad Aghaei" and "Kaleghoochi", an orchard experiment in the form of a randomized complete block designwith three replications and three factors, cultivar (Ahmad Aghaei and Kaleghoochi), different levels of potassium fertilizer (0, 200, 300 and 400 mg of potassium per liter of irrigation water) and year (2017 and 2018) was done. The results showed that the nut potassium content and the fresh weight of the fruit with the hull increased in the second year of the experiment. Fresh weight of the fruit with the hull, nut length and kernel length were higher in Kaleghoochi cultivar than Ahmad Aghaei cultivar. While the percentage of half kernel and nut width was higher in Ahmad Aghaei cultivar. With the application of potassium, the fresh weight of fruit with hull and without hull, fresh weight of kernel, nut length and width and width, thickness of kernel and leaf potassium increased. In Kaleghoochi cultivar, compared to Ahmad Aghaei cultivar, fresh fruit without skin and kernel, nut thickness and width and thickness of kernel increased in both years. Potassium application in both years increased nut thickness and kernel length and significantly reduced half kernel percentage and deformity. The amount of nut potassium in both cultivars increased with the application of potassium.In the first year and in both cultivars Ahmad Aghaei and Kaleghoochi the use of potassium had a significant effect on reducing regular and irregular early splitting.