Effect of Kaolin clay on pistachio psylla nymph, Agonoscena pistaciae

Pistachio psylla، Agonoscena pistaciae Burckharat & Lauterer (Hem.: Psyllidae)، is the most important pest of pistachio orchards in Iran، feeding on leaves، resulting to reduce the quantity and quality of product. In order to reduce the use of chemical insecticides، the application of kaolin particle film was tested in the fields of four regions of Iran (Razavi Khorasan، South Khorasan، Semnan & Qom regions)، during 2012 year. The different concentrations، 3 and 5%، of kaolin clay (Sepidan® WP) and acetamiprid were sprayed over the whole canopy three times at 4 to 5 -week intervals from mildly May to mildly July. Based on the field studies، kaolin (5%) application reduced the population of psylla nymphs more than acetamiprid at all spraying stages in pistachio trees. The rate of efficacy percent for psylla nymph control، at three days after spraying، were 30. 3، 54. 3 and 43. 5 for kaolin (3%)، kaolin (5%) and acetamiprid treatments، respectively. Also، control ability for psylla nymph was appropriate up to 21 days after spraying، in kaolin treatments compared with acetamiprid treatment. The rate of efficacy percent was 48. 3، 78. 3 and 47. 6%، for kaolin (3%)، kaolin (5%) and acetamiprid treatments، respectively. Therefore three to four times at 4–5-week intervals spraying kaolin (Sepidan® WP) at the concentration (5%) over the whole canopy of pistachio trees can be used successfully to reduce psylla nymph on pistachio.