Economic evaluation of different insecticide applications for control of the olive moth, Prays oleae (Bern.), in 'Gemlik' olive trees

Abstract

The olive moth Prays oleae (Bern.) is the major insect pest on olive trees, causing flower depletion and fruit drop in Bursa (Turkey). An economic evaluation was performed in this study based on our observations from an olive grove plot different insecticide treatments, pyriproxyfen versus deltamethrin+diflubenzuron and deltamethrin+thiacloprid mixtures, were applied against larvae of the pest in 2013 and 2014. Economic parameters total turnover and total costs of cultural and crop protection activities were obtained from untreated and sprayed plots. The real cost of the treatments was calculated using factors such as effects to the environment, cost and efficacy of spraying. Total turnover was computed using prices of the crop depending on fruit quality. Higher blooming, fruit formation and yield were recorded in all plots in 2013 than 2014. Although there was no significant difference between the damage and yield parameters of sprayed plots, significantly higher market value and profit were obtained in the plot to which insecticide mixtures were applied compare with the plot sprayed with pyriproxyfen in the year of higher yields, because of the larger fruit size, but not in the year of lower yields. Compared with the untreated plot, the rates of increase in yield and total receipt were higher in 2014 than in 2013. The cost effect of insecticide spraying was more in the year of lower yields. In any case, the damage rate of the pest was not reduced below the economic threshold recommended in Turkey for insecticide treatments.