تعیین مناسب‌ترین زمان‌ها برای کنترل کرم سیب، Cydia pomonella برمبنای محاسبه‌ی مقدار گرمای موثر ساعتی(GDH)

Codling moth, Cydia pomonella is the key pest of apple orchards in Iran. In order to succeed in chemical control of this pest and reduce the number of spraying against it, using modern and accurate methods is of great importance. Nowadays, the most accurate prediction method which is used to predict the occurrence of different phenological stages of pests is using an estimate of the total environmental efficient temperature based on Degree-Days. In this regard, this study was conducted in two locations of Kamyaran and Saqez durind 2015 and 2016, In order to prepare a predictive model of Codling moth based on the estimation of total efficient temperature from the environment (GDH). In order to determine the beginning date of recording environment temperature and the calculation of efficient temperature, biofix was determined based on the hunting of pheromone traps. From this date until the harvesting time, fluctuation of environment temperature were recorded in the garden hourly and the efficient temperature from the environment was calculated based on the temperature indices of the growth and development of Codling moth hourly. In the following, from the date of biofix, the population fluctuations of the different biological stages of the Codling moth were recorded in both regions weekly until harvesting of apples. Based on the results, in both of the studied areas, there were two distinct flying peaks indicating two generations of Codling moth in Kurdistan province. Considering that the best time to perform chemical control of Codling moth is at the peak of the larvae population of the first instar and before entering them into fruits, the results of two years of research in both Kamyaran and Saghez showed that the peak population of the first-generation larvae of the winter-generations is 6634±430 GDH, and in the summer generation is 23700± 846 GDH.