Biological control of Fusarium head blight (Fusarium graminearum) by application of three native Trichoderma species in field

Fusarium disease of wheat is one of the important diseases in wet and subtropical regions in Iran. Using the biological agents is effective in controlling this disease. In this experiment, were used 3 species of native Trichoderma: T. atroviridae, T. harzianum and T. virens as biological agents. Also to compare between the effects of fungicide and antagonist agents were used of Propiconazole. Tested on two wheat cultivars Falat & Moghan, in the form of spilet plot-factoriel with 3 replications in the field conditions. When spikes were in the pollination stage they were sprayed in three different times: T1 (first sprayed with Trichoderma suspensions (3×107/ml) and two days after sprayed with Fusarrium suspentions (3×105/ml)), T2 (sprayed with Fusarium and Trichoderma simultaneously) and T3 (first sprayed with Fusarrium suspentions (3×105/ml) and two days after sprayed with Trichoderma suspensions (3×107/ml)). The mean comparisions showed that all control treatments had a significant difference, with infected control treatment(p=95%), and in infected control treatment was higher infection rate and severity of pollution and was less thousand grain wighte, compared with other treatments. In other treatments, fungicide treatment was less infection rate and severity of pollution and was higher thousand grain weight and yield compared with antagonistic treatments (p=95%). In different times of sprayed in relation to infection rate and severity of pollution and yield, the results showed that the treatments which were used at T1 better results compared with the time T2 and T3. Consequently, the time T1 was known as the most efficient use Trichoderma. In relation to varieties of wheat the results showed that, between two cultivars wheat were significant difference and cultivar of moghan showed the better results compared with falat cultivar.