ارزیابی آزمایشگاهی قارچکش‌های مختلف بر میزان تندش قارچ Sporisorium scitamineum عامل سیاهک نیشکر در استان خوزستان

Sugarcane smut with agent Sporisorium scitamineum is an air-borne disease that was discovered at Natal of South Africa for the first time in 1877. Smut is one of the first reported diseases of sugarcane because of the appearance of black whips at the terminal part of a plant. Some commercial varieties of sugarcane such as Nco310 have damaged smut. The primary infection is sett-born and is caused by infected cuttings after cultivation. Ratooning causes the disease to spread indirectly and in ratoon fields, it reduces the yield by about 30-40%. In this study, the effectiveness of several systemic fungicides such as Carbendazim, Thiophanate methyl, Carboxin thiram, Propiconazole, Amistar xtra, and Flutriafol on the germination of teliospores has been investigated in the laboratory and an experiment was conducted in the form of a completely random design with 84 treatments and three replications. These fungicides were prepared with concentrations of 0.5, 1, 1.5, 2, 5, 10, 20, 50, 100, 200, 500, and 1000 PPM and added to the water agar medium. Then the teliospores were cultured on the petri dishes containing water agar medium and kept in the incubator at 28-30 oC for 24 hours. Spore germination was determined under a compound microscope through Shamsul et al. method. Averages comparisons were done through Duncan test by means of SPSS22 software. Based on the results of this test, after control treatment, Carboxymin tyram toxin at a concentration of 1 ppm did not intensify any spores, which in this regard has the best performance among all treatments, and then Amistra xtra toxin at a concentration of 20 ppm was successful. To prevent the germination of 100% spores of the fungus. Also, at concentrations less than 1000 ppm of Flutriafol toxin, 100% of the teliospores germinated and in this regard, the toxin had the least effect on the germination of teliospores of this fungus. According to the results of this experiment, Carboxymin thiram and Amistra xtra were selected for greenhouse and field testing. It should be noted that the greenhouse experiment is underway.