Experiments were conducted in vitro and in the field, in Passo Fundo, Rio Grande do Sul, Brazil, in 1999 and 2000 in order to test the combination of bioprotector and fungicide against wheat (Triticum aestivum) seed pathogens. The following products and doses per 100 kg of seeds were used: Paenibacillus macerans (Embrapa 144), 13 g; P. macerans + difenoconazole 15 FS (13 + 200 ml); P. macerans + difenoconazole (13 g + 100 ml); P. macerans + difenoconazole 15 FS (6.5 g + 100 ml); difenoconazole 15 FS, 200 ml. A non treated check was maintained in the experiment. All chemical and biological treatments effectively controlled the wheat seed pathogens. The combination P. macerans Embr. 144) (13.0 g) + difenoconazole 15 FS (200 ml) completely or almost completely eradicated seed pathogens. Powdery mildew was effectively controlled only by seed treatments containing difenoconazole 15 FS, from 35 up to 40 days after sowing. All fungicide treatments significantly improved plant stand and grain yield. The beneficial effects were greater when P. macerans (Embr. 144) was applied in combination with difenoconazole 15 FS, even when the fungicide dose was reduced to half.
