Fındık üretim alanlarında kullanılan bazı fungisitlerin Trichoderma türlerine karşı etkilerinin belirlenmesi

Received 05 April 2020 Received in revised form 16 June 2020 Accepted 18 June 2020 In this study, the effects of some fungicides (boscalid+kresoxim methyl, fluopyram+tebuconazole, sulphur ve tetraconazole) used for control of powdery mildew disease in hazelnuts on Trichoderma harzianum (11-TTR-2), T. hamatum (F4), T. atroviride (T-4-5) and T. asperellum (T-11-25) were evaluated under in vitro conditions. The study showed that all concentrations (0.25×, 0.5×, 1.0× and 2.0×) of the fungicides significantly reduced the mycelial growth, spore germination and germ-tube elongation of Trichoderma isolates, when comparing to the control (P<0.05). Especially, fluopyram+tebuconazole was found to have the higher inhibitory effect to mycelial growth, spore germination and germ-tube elongation of all the isolates. Even at the lowest concentration (0.0625 mL L) used in the study, fluopyram+tebuconazole completely inhibited the mycelial growth of T. hamatum and T. asperellum, whereas it reduced mycelial growth of T. harzianum and T. atroviride by 93.97% and 89.48%, respectively. On the other hand, tetraconazole at a much higher concentration (1.0 mL L) were able to decrease the mycelial growth of T. harzianum and T. atroviride by 82.16% and 95.61%, respectively. Boscalid+kresoxim methyl and sulphur inhibited the mycelial growth of all four isolates at rates between 26.64-63.59% and 6.75-30.81%, respectively. The EC50 and the minimum inhibitory concentration (MIC) values indicated that fluopyram+tebuconazole was more toxic to all the isolates than tetraconazole. As a result, this study showed that boscalid+kresoxim methyl and sulphur can be recommended in hazelnut orchards, where Trichoderma spp. should be used against Xylosandrus germanus.