International Journal of Applied Agricultural Research

In order to assess possibility of application the fungicides and biocontrol agents simultaneously, sinsitivity of five Trichoderma species to Carboxinthiram, Triadimenol, Carbendazime and Rovral TS fungicides commonly used to control common bunt of wheat and barly was studied in Iran. The various concentrations comprising of 0.01, 0.1, 0.5, 1, 10, and 100 mg/l active ingredient from each fungicide in ¼ -strength PDA medium were used on mycelial growth and sporulation rate of Trichoderma species. Results showed that the range of EC50 for Carboxinthiram, Triadimenol, Carbendazym and Rovral TS was 17.1–21.87, 2.71–17.09, 0.13–0.40 and 0.19–0.48 mg/l respectively on mycelial growth of Trichoderma species with 95% confidence limitation. On the basis of EC50, carboxinthiram and triadimenol were selected for more evaluation. Inhibitory property of both fungicides was than examined on spore germination of Trichderma species in PDB medium containing 1000 mg/l active ingredient of fungicides in vitro. Carboxinthiram and Triadimenol reduced the spore germination of Trichoderma at the rate of 100% and 41–52.3% respectively. Consequently, on the basis of obtained EC50 of fungicides on the rate of colony growth and percentage of spore germination, Triadimenol was distinguished more compatible than other experimented fungicides with Trichoderma species in typical application rates against common bunt.