Proper potassium nutrition of pistachio trees is the key to efficiency and increased Iranian Pistachio yield in pistachio orchards. Studies show that the highest amount of potassium in the leaves is observed in August and September of each year, when the seeds go to the kernel or fill in the leaves.

Therefore, in this critical time period, the tree should not be deficient in potassium; Especially the potassium available in the roots. It has been found that the amount of potassium uptake in pistachio trees is relatively low in May and the amount of potassium uptake from the soil is at its lowest level.

Potassium concentrations in the leaves of pistachio trees are estimated to be below 1% in spring, and this concentration increases dramatically during fruit growth and development; Especially in the months of July to September. Finally, at the time of puberty and the end of skin and brain formation and the end of the growth period, ie approximately in September, we will have the maximum absorption of potassium from pistachio roots.

The concentration of potassium in the leaves decreases abruptly in October, the post-harvest period; Specialized channel of vegetation and agriculture, therefore, there is no need to use potash fertilizer in the post-harvest period in pistachio orchards; Whether as a foliar spray or as a soil application.