Inhibition effect of fungicides on mycelium of Fusarium nivale, F. culmorum and F. equiseti

The fungicides inhibition effect of azoxystrobin, carbendazim, benomyl, tebuconazole + triadimefon, kresoxim-methyl + epoxiconazole, carbendazim + propiconazole and carbendazim + prochloraz was investigated on mycelium of Fusarium nivale (strain 44), F. equiseti (strain K-61) and F. culmorum (strain 1/3-5). The fungi were isolated from triticale. The 2% potato-glucose agar was used as cultivation medium, prepared adding of fungicides in concentrations as follows: - azoxystrobin, tebuconazole + triadimefon, kresoxim-methyl + epoxiconazole 0,1 - 0,2 - 0,4%, - carbendazim + propiconazole 0,2 - 0,4 - 0,8%, - carbendazim and benomyl 0,05 - 0,1 - 0,2%, - carbendazim + prochloraz 0,15 - 0,3 - 0,6%. In series A, the fungi were cultivated at 20oC, 12 hours fotoperiods and illumination 4000 lx, in series B at 2 degree C, without illumination. The toxic agar discs were inoculated using a small agar disc of Fusarium mycelium, which was separated from margin of fresh Fusarium cultures. The speed of mycelium growth was evaluated each day in series A, each the fifth day in series B. The efficacy of fungicides was specify as mycelium growth inhibition. In series A, the daily increase of mycelium was calculated using of pattern where d24 and d48 are values of Ð = d48-d24 of radial mycelium growth, measured out after 24 and 48 hours. In series B, the daily increase of mycelium was calculated as follows where - d2 - daily mycelium increase, measured out after five days d = (d2 - d1) : 5, - d1 is diameter of colony, measured out by previous measurement. The 100% inhibition of F. nivale mycelium were recognised using of tebuconazole + triadimefon, carbendazim + propiconazole, carbendazim + prochloraz. It was less under azoxystrobin, kresoxim-methyl, carbendazim and benomyl application. The 100% inhibition effect was recorded using of all fungicides, excepting azoxystrobin, on F. culmorum and F. equiseti mycelium. Different sensitivity of Fusarium spp. to fungicides was found, therefore the efficiency of fungicides is necessary to evaluate separately, specially for each species