One of the most important pistachio shell operations was irrigation during the season. The pistachio tree needs a certain amount of water at each stage of growth. It seems that the stages of pistachio fruit development based on importance from the perspective of irrigation are: flowering and filling of the kernel, fruit formation, kernel filling and finally ripening of the fruit and its laughter.
It should be noted that the lack of water supply of trees in April at the time of flowering and the time of filling of the brain (usually July) leads to emptiness and abortion. The smiling stage of bony skin at the time of the last water before harvest is also one of the steps that should be considered. Irrigation during fruit formation and after pollination (late April) affects the number of seeds in the tree. Also, it is better to pay attention to irrigation during maturation and filling in late August and early September, because due to hot weather and lack of water, the trees are under stress and the lack of water supply to the trees leads to hollow and half-brain. . Of course, a set of factors such as irrigation management, nutrition, pest and disease control and…. Affects the weight and size of the fruit during the season.
Although the most sensitive stage of growth of pistachio trees to water stress is the time of flowering and kernels, but some gardeners are afraid to irrigate their gardens at the time of flowering! He states that irrigating pistachio trees at this time causes the flowers to fall. Therefore, in this section, we considered it necessary to provide an explanation in this regard in order to clarify the matter.
Trees are not able to absorb water from the soil in two cases. When the soil is dry and there is no water to absorb, and the second is when the soil is saturated with water and there is no air in the soil. Only if the three components of water, soil and air are together, the necessary conditions for water uptake by the plant roots are provided. With these interpretations, during irrigation, trees can not absorb water from the soil; Because at this time the soil is saturated and there is no air in it. That is why it is said not to irrigate the gardens at noon, because at this time the plant needs water the most, while water absorption stops. Therefore, the plant suffers from so-called suffocation and damage. Depending on the type of soil, this saturation lasts between 24 hours (in very light sandy soils) and up to 4 to 5 days (in heavy clay and alkaline soils) after irrigation. In this case, the plant is under water stress. Therefore, in order to solve the problem in soils with low permeability at the time of flowering, heavy irrigation should be avoided. In conditions where the water and soil are saline, due to the high concentration of salt in the soil solution, water absorption is slow and the soil saturation may remain for a longer time.
