Inhibitory Effects of Three Trichoderma Species Against three Species of Fusarium in Laboratory Conditions

The gnu Fusarium encompasses economically important plant pathogens. The common strateigies for the disease control, alone, are not fully efficient. Hence, the use of alternatives methods is necessary for the disease management. In present study, the inhibitory effects of three Trichoderma species (T. harzianum, T. longibrachiatum and T. tomentosum) against three species of Fusarium (F. monoliforme, F. semitectum and F. solani) were evaluated in laboratory conditions on PDA medium in 25 oC and five replicates. Experiments were conducted in two parts: dual culture and the effects of volatiles against pathogenic fungi and colony diameters were measured six and four days after incubation, respectively. In dual culture test the highest inhibitory effect was related to T. harzianum / F. moniliforme treatment while the lowest effect was observed in T. tomentosum / F. solani treatment. Inhibitory effects of three Trichoderma species on mycelial growth of F. moniliforme did not significantly different (p< 0.05), while they had significantly different effects (p<0.05) on the other two Fusarium species. Treatments related to volatile production had different results, so that the most and the least inhibitory effects were observed in T. tomentosum / F. solani and T. tomentosum / F. semitectum treatments, respectively. The overall results of this study showed that there are significant differences in interaction among the different Trichoderma species and Fusarium species; such that, primary tests on the efficacy of Trichoderma species on target plant pathogenic fungi is necessary before commercial usage of such products.