Is it possible to determine economic injury level by Delphi method? A Case Study of Ommatissus lybicus

Dubas bug, Ommatissus lybicus, is one of the key pests of date palm groves in Iran. Chemical control is currently used regardless of the population of pests and its economic problems. The aim of this study was to determine O. lybicus economic injury level with a different method from the conventional method which is easier with the same precision. Therefore, Delphi method or expert system was used. It was carried out in the three provinces of Kerman (Bam), Fars (Farashband), and Bushehr (Tang-e zard). Twenty-five questionnaires were distributed between experts and farmers in each province. The completed questionnaires were collected. According to the results of the first questionnaire, the second questionnaire was compiled and the stages were repeated. The results showed that the Delphi method provides valuable results such as the description of individual variables (the age of palm growers, literacy, level of experience, garden area and gardener pest management) that can be effective in pest management planning. However it could not produce accurate results for quantitative data such as determining the timing of chemical control according to pest number, the amount and percentage of damage, because this data is available and the Delphi method should not be used as an excuse, in such cases the Delphi technique can be used as a complementary method.