ارزیابی کارآیی قارچ‌کش پیراکلو استروبین 7/6% + بوسکالید7/26 % (WG 33.4%) علیه Botrytis cinerea عامل بیماری کپک خاکستری فلفل در شرایط گلخانه

Gray rot disease caused by Botrytis cinerea is one of the most important diseases of pepper. In addition to being economically important in the greenhouse and field, this disease is also one of the damaging factors in the post-harvest and storage conditions. Chemical control using fungicides is one of the main components of gray rot disease management of pepper and other greenhouse products, therefore testing and registering new and effective fungicides is necessary to control the disease. In this research, the efficacy of Pyraclostrobin 6.7% + Boscalid 26.7% (Target fungicide) with contact and systemic properties in controlling pepper gray rot disease in laboratory and greenhouse conditions was investigated and were was compared with Captan fungicide WP50%. The research was carried out in laboratory conditions in the form of a completely randomized design and in greenhouse conditions in the form of a randomized complete block design in Hormozgan and south of Kerman province. Each experimental plot consists of two rows of four meters long, and 10 plants in each experimental plot were marked and used for statistical purposes. The treatments included target fungicide with dosages of 1g/L, 1.5 g/L and 2 g/L, Captan at the rate of 3g/L (reference fungicide), and control without any fungicide. After observing the first symptoms of the disease, spraying of treatments was started and continued until the disease severity in the control treatment reached about 75%. The foliar spraying was repeated every 7 to 10 days and three times in total. The disease severity index (DSI) was calculated for each plant with a scoring system. The data were analyzed with SAS statistical software and the mean data were compared using Duncan's multi-range test at the five percent probability level. In laboratory conditions, the results showed that all the treatments reduced the radial growth of the disease-causing fungus compared to the control, and statistically, a significant difference was observed at the level of 1%. The results of analysis of variance in both regions showed that there is a significant difference at the level of 1% between the treatments and the control in terms of the effect of fungicides in reducing the disease severity index. The results showed that target fungicide at concentrations of 1.5 and 2 g/L were the best, respectively, with an average control efficiency of 93.8 and 88.25%, and with a concentration of 1 g/L along with Captan, with control efficiency of 86.08 and 80.94, respectively, located in the next category. According to the average results of both regions and in order to reduce the consumption of fungicides, Pyraclostrobin + Boscalid treatment with a concentration of 1.5 g/L and depending on the conditions, 2-3 times applications are recommended to control the gray mold disease.