Abstract :
We aimed to investigate the effect of tebuconazole, a fungicide, on in vitro development of the 10 isolates of Fusarium culmorum (WG Smith) Sacc. collected from the diseased wheat plants in Çanakkale. For this purpose tebuconazole at different concentrations (0.01, 0.05, 0.1, 0.5, 1, 5, 10, 50, 100, 500 ppm) was added into PDA nutrient medium and then fungus mycelial growth, conidium germination, germ tube elongation, germ tubes changes were observed. Mycelial growth was slower at 1 ppm and lower doses, but inhibited completely at doses of 10 ppm and over. Conidia of the fungus germinated even at as high as 50 ppm concentration althoght germination was deteriated in few isolates. Time course studies showed that germ tube length could be measured at 6 hours after incubation, however measurement was imposible below 10 ppm concentration at 12, 18 and 24 hours after incubation. The fungus continued to alongate even at 100 pp concentration 18 hours after incubation, and no measurement could be done later on. We observed that conidium germination occured no matter how high the tebuconazole concentration was; however mycelial growth and germ tube elongation affected with the higher concentration of the fungicide. We concluded that tebuconazole could be effective to control F. culmorum, taking in conseridation that some external factors will affect the success such as climate, resistance of the variety and application procedure.
Keyword :
Fusarium culmorum, Germ Tube, Codinia Germination, Wheat, Tebuconazole