Effect of Kaolin clay on Codling moth, Cydia pomonella

Codling moth, Cydia pomonella Linnaeus (Lep.: Tortricidae), is the most important pest of apple orchards, feeding on fruits, 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 tree regions of Iran (Tehran, Razavi Khorasan, & Zanjan regions). The different concentrations, 3, 4 and 5%, of kaolin clay (Sepidan® WP95%), and diazinon (Diazinon® EC60%) and fozalone (Zolon® EC35%) insecticides were sprayed over the whole canopy, three times from early June to late August. Based on the field studies, kaolin-5% had a similar efficacy to chemical insecticides. The mean of codling moth infestation in fozalone, diazinon and kaolin-5% treatments were 14, 16 and 16.4%, respectively, compared to the control (44.6%). The use of kaolin increased the weight and diameter of the fruits and the chlorophyll index and photosynthesis amount of the apple trees. In the kaolin-5% and control treatments, the mean fruit weight were 247 and 146 g, and the mean fruit diameter were 78.6 and 75 mm, respectively. Also, the chlorophyll index was 53.8 and 51.5, and the photosynthesis rate was 5.91 and 4.93 μmol/m2/s, respectively. Therefore, due to the high effect of kaolin in reducing of pest damage and also no adverse effect on trees, spraying kaolin (Sepidan® WP) at the concentration 5% over the whole canopy, before the peak of moth oviposition, can be used successfully to reduce codling moth on apple.