Investigation on the Efficacy of myclobutanil (Atis® WP 40%) against Apple Scab Disease with the agent Venturia inaequalis

Apple scab disease is one of the most important diseases of apple worldwide. Due to its high injury levels use of chemical pesticides for its management is inevitable. In the present study, the efficacy of myclobutanil (Atis®) in comparison with common fungicides including Captan (Captan© WP 50%), Trifloxystrobin(Flint© WG 50%), Trifloxystrobin + Tebuconazole (Nativo© WG 50%), Trifloxystrobin + Fluopyram (Luna Sensation© 500SC) was evaluated against apple scab disease. The experiment was carried out in a Randomized Complete Block Design with 9 treatments and 4 replications in Kohgiloyeh and Boyerahmad (yasuj) and Ardabil (Ardabil) provinces. Treatments included 0.142, 0.228 and 0.314 ml L-1 of  Atis®, 0.2 ml L-1 of Flint®, 0.2 ml L-1 of Nativo® , 0.4 ml L-1 of Luna Sensation®, 3 g L-1 of Captan®, and controls (without any spraying and with water spraying). Treatments were applied at three stages (silver tip stage which followed up at the end of flowering stage and 14 days after the 2nd spraying). The incidence, severity of the disease and mean comparisons were calculated and analyzed. Results show that fungicides treatments were significantly different from both control treatments. The results of the experiments in both locations show the efficacy of Atis at the rate of 0.314 and 0.228 ml L-1 in Yasuj was 97% and 88% and in Ardabil it was 62% and 55% respectively. Similarly, the efficacies of Luna Sensation at the rate of 0.4 ml L-1 and Nativo at the rate of 0.2 ml L-1 were 90% and 86% in Yasuj and 64% and 55% in Ardabil respectively. In conclusion, Atis at the rates of 0.314 and 0.228 ml L-1, Luna Sensation at the rate of 0.4 ml L-1 and Nativo at the rate of 0.2 ml L-1 had the highest efficacy against the apple scab disease.