عنوان مقاله [English]
The Codling moth Cydia pomonella (L.) (Lepidoptera Tortricidae) is a pest of worldwide importance that exhibits seasonal phenology that is mainly affected by temperature. This pest is the most important pest in Iranian apple orchards. In order to avoid the unnecessary usage of chemical pesticides, using pheromone traps and degree- day Model is the most effective control way. The pest phenological stages and the best time of spraying can be predicted with the degree- day model and Pheromone Traps. The purpose of this study is determine the best time of spraying Codling moth to Reduce Damage and Environmental Protection.
Materials and Methods: The pheromone traps and temperature Data Logger were planted in a orchard To determine the best time of spraying Codling moth in Chenaran. sex pheromone traps were planted in the garden and The number of trapped males was recorded every five days. The history of the first males trapped in pheromone traps was considered biofix. Degree-days were calculated and recorded using mean daily temperature and base temperature. temperature datalogger was installed to record the temperature in the orchard. To calculate the base temperature, number of Codling moth eggs kept at different temperatures. The growth rate was calculated at this stage of pest life After determining the number of days needed for egg hatching. The temperature at which the growth rate becomes zero was considered as the base temperature. after Flying Peaks, Thirty Codling moth eggs were sampled and The spraying was done when fifteen eggs were hatched. There were three experimental treatments in the orchard. A: The first treatment was spraying on the proposed degree- day model and pheromone traps. B: The second treatment was spraying according to the farmer's opinion. C: Third treatment The spraying was not done. The degree- day model was evaluated using the percentage of impact method. In this method the percentage of healthy fruits of treatment A was compared with treatment C and the percentage of healthy fruits of treatment B was compared with treatment C.
Results and Discussion: The basal temperature of codling moth was 8.4 ° C. The first males trapped on 25 April 2019 and it was Biofix. Pheromone Traps data showed three flight peaks. This means that there are three generations of Codling moth in the Study Area. In the Last year, Codling moth lay many eggs in different places. These eggs hatch in the New Year at different times. So the population of the first generation of Codling moth was so many. for the first generation, two spraying stages were performed. The first was done at 168 ° C degree- day and second at 343° C degree- day. Spraying was performed for the second generation at 804 degree- day. Spraying was performed for the Third generation at 1505 ° C degree- day. The fourth generation of this pest was incomplete and Spraying was performed for the fourth generation at 2148 ° C degree- day. These spraying were done in treatment A. The results show the best time to counter the pest is in the first generation, 4 to 6 days after flight peak, the second generations 4 to 6 days after flight peak, the third generations 3 to 5 days after flight peak and the Fourth generations 6 to 8 days after flight peak. In treatment B: The farmer sprayed seven times. The spraying dates were selected experimentally. The percentage of effect in treatment A was 78.5% compared to treatment C and The percentage of effect in treatment B was 49.7% compared to treatment C. the number of sprayers decreased in treatment A compared to treatment B and Treatment A was more effective than treatment B.
Conclusions: Spraying at the best time in addition to reducing the number of spraying, It also reduces damage to the fruit. The Pheromone Traps and degree-Day Model in this study is expected to be useful for field applications in integrated pest management (IPM) systems, for example, to forecast optimal spray times for available insecticides and application of other control measures. By reducing the use of chemical pesticides Useful enemies will do less damage and the environment will be preserved. In order to avoid the unnecessary usage of chemical pesticides, using pheromone traps and degree- day model are the most effective control way.