ارتباط انبوهی جمعیت پسیل معمولی پسته با برخی عناصر غذایی پرمصرف و کم مصرف

The common pistachio psyllid, Agonoscena pistaciae Burckardt and Lauterer (Hemiptera: Aphalaridae), is one of the most important pests of pistachio trees in Iran, which causes economic damage to pistachio trees every year. The population density of common pistachio psyllid depends on the physiological conditions of the pistachio trees. In this study, the relationship between the population density of common pistachio psyllid with the content of some macronutrient elements (nitrogen, potassium, phosphorus) and micronutrient elements (iron, zinc and copper) of leaves was evaluated. The samplings were done on low density (0-50), medium density (51-100) and high density (more than 100 numbers) of eggs and nymphs of common pistachio psyllid on apical leaflet of leaves of pistachio trees. Then, leaves analysis showed the content of these macro and micronutrient elements in different densities. Leaf analysis was done using a spectrophotometer for phosphorus and nitrogen elements, a flame photometer for potassium element and inductively coupled plasma for micronutrient including iron, zinc and copper. The regression relationship was used to investigate the relationship between population density of common pistachio psyllid and the content of elements. The results showed that the higher density population of common pistachio psyllid was in the leaves with the higher content of nitrogen, zinc and iron elements, and it was lower in the leaves with higher content of phosphorus, potassium and copper elements. Therefore due to economic damage of common pistachio psyllid, it is important to use phosphorus, potassium and copper nutrients to increase resistance and not to use nitrogen, zinc and iron nutrients to reduce the sensitivity of pistachio trees, especially in kernal growth stage that is critical stage of pistachio trees growth.