Volatile organic compounds (VOCs) produced by microorganisms are potential alternatives for the development of new nematicides. In a previous study, we identified VOCs produced by Fusarium oxysporum strain 21 (F.o–21). In this study, we tested the eight most abundant VOCs produced by F.o-21 against Meloidogyne incognita. Compounds 2-methylbutyl acetate (1), 3-methylbutyl acetate (2), ethyl acetate (7), and 2-methylpropyl acetate (8) led to in vitro mortality of 100%, 91%, 100%, and 82%, respectively, in second-stage juveniles (J2) of M. incognita at a concentration of 500 μg/mL. The lethal concentration (LC50) for compounds 1, 2, 7, and 8 in M. incognita J2, was 236, 198, 213, and 218 μg/mL, respectively. Under the same conditions, the commercial nematicide called carbofuran (2,3-dihydro-2,2-dimethyl-1-benzofuran-7-yl N-methyl carbamate) showed an LC50 of 191 μg/mL. Eggs exposed to compounds 2 and 7, for 72 h showed up to a 90% reduction in hatching, and the compounds 1, 2, 7, and 8 reduced M. incognita infectivity by 52%, 52%, 36% and 41%, respectively. When the compounds were applied in tomato seedlings infested by M. incognita, compound 1 reduced the number of galls per root gram by 22% when compared to the negative control (without the application of nematicide). The compound 2-methylbutyl acetate (1) showed potential to be used in the field after improvements in the application technology.
- Fusarium oxysporum
- Plant-parasitic nematodes