Bacillus- and Trichoderma-based products control the spiral nematode Helicotylenchus dihystera in soybean

Soybean (Glycine max) is significantly affected by plant-parasitic nematodes. The spiral nematode (Helicotylenchus dihystera) is considered a potential parasite for Brazilian soybean. This study investigated the efficiency of microorganism-based products against H. dihystera in soybean and possible mechanisms involved in the control. Products based on Bacillus and Trichoderma were compared to a chemical nematicide (abamectin). By in vitro tests, all products killed H. dihystera. Production of toxic compounds was tested by using cell-free culture filtrate or by volatile emission. Filtrates of Trichoderma and Bacillus killed more than 85% of H. dihystera. The volatile emitted by Bacillus-based products also killed the nematodes. All products increased soybean growth and controlled H. dihystera in pots with infested soil, where B. amyloliquefaciens-based products stood out. The field experiment confirmed the efficiency of abamectin and Bacillus against H. dihystera. Therefore, the microorganism-based products produced compounds toxic to H. dihystera and benefited soybean under infested soil.

Automated summary

This study investigated the efficacy of microorganism-based products, including Bacillus and Trichoderma, against the potential parasite Helicotylenchus dihystera in soybean. The products killed the nematodes by producing toxic compounds or emitting volatile substances, leading to improved soybean growth in infested soil.