Efficacy of the Fungicide Triflumizole (Trifmin® EC 15%) in Controlling Apple Powdery Mildew Disease

Apple powdery mildew is one of the most important and common fungal disease of apple trees that reduces the quantity and quality of this fruit. The efficacy of Triflumizole (Trifmin® EC 15%) as a target fungicide in controlling apple powdery mildew was evaluated in a randomized complete block design with seven treatments including:  0.5/1000, 0.75/1000, 1/1000 and 1.25/1000 of Triflumizole, 0.3/1000 of Trifloxystrobin + Tebuconazole (Nativo® WG 75%) as control fungicide, control with water spraying and control with no spraying in four replications. The field trials were undertaken in three provinces of Isfahan (Semirom), Kohgiloyeh Va Boyerahmad (Yasuj) and eastern Azerbaijan (Tabriz). Three commercial orchards of susceptible cultivar Golden delicious (seedling rootstock) with a history of infection were selected. Sprayings were done three times (at swelling flower buds stage), at the end of flowering time and two weeks later. The sampling of leaves was carried out at the end of the summer. The evaluation of experimental plots was performed in the second half of September and at the same time with the completion of the apical buds, by random selection of 50 leaves from 10 branches and by calculating the percentage of occurrence and the percentage of disease severity based on Spencer's scales. Data were analyzed for variance and mean comparison with SAS program through Duncan Multiple Test at 5% probability level. Comparison of Mean showed that concentrations of 1/1000 and 1.25/1000 of Triflumizole and 0.3/1000 of Trifloxystrobin + Tebuconazole with 78%-93% and 79%-95% reduction in incidence and severity of the disease compared with the control with no foliar spraying in one group respectively Therefore based on the results Triflumizole with the concentration of 1/1000 is recommended for the management of apple powdery mildew.