Interactions between Heterodera filipjevi and Fusarium culmorum, and between H. filipjevi and Bipolaris sorokiniana in winter wheat

Pot experiments with winter wheat were conducted for two successive years to study the relationship between the cereal cyst nematode, Heterodera filipjevi, and the soil-borne fungi, Fusarium culmorum and Bipolaris sorokiniana. Plant height, shoot weight, and root weight were significantly (P ≤ 0.05) reduced by simultaneous inoculation of the nematode and F. culmorum. Simultaneous and sequential inoculation of H. filipjevi and F. culmorum reduced the grain yield more than inoculation with each pathogen alone. Maximum reduction in grain yield occurred with simultaneous inoculation of H. filipjevi and F. culmorum and was significantly different from the other treatments. Grain yield was not affected significantly by any combination of H. filipjevi and B. sorokiniana treatments. Nematode reproduction on wheat roots was reduced significantly when the nematode and the fungi were inoculated simultaneously or sequentially compared to H. filipjevi inoculated alone. No synergistic interactions were detected when plants were co-infected by the nematode and either one the fungi.