Nematicidal activity of allyl bromide and dibromo(nitro)methane under laboratory conditions

Restrictions on soil fumigants are prompting the development of new compounds for controlling nematodes, other soilborne pathogens and weeds. We evaluated the nematicidal activity of five bromine compounds against Meloidogyne javanica in vitro, and tested the two most effective ones against Pratylenchus penetrans and Xiphinema index in vitro and in soil.

Only allyl bromide and dibromo(nitro)methane showed nematicidal activity against M. javanica juveniles in vitro at <320 mg L(-1) . Allyl bromide killed M. javanica and P. penetrans at 20 mg L(-1), and X. index at 10 mg L(-1), whereas 320 mg dibromo(nitro)methane L(-1) was required to kill P. penetrans. Allyl bromide also showed higher nematicidal activity than dibromo(nitro)methane against M. javanica and P. penetrans in soil. Allyl bromide at 40 and 20 mg L(-1) soil eliminated root galls and nematode eggs on tomato roots grown in M. javanica-inoculated loess and sandy soils respectively, showing higher nematicidal activity than 1,3-dichloropropene. No P. penetrans were recovered from soil treated with 80 mg allyl bromide L(-1) soil or 320 mg dibromo(nitro)methane L(-1) soil.

Allyl bromide showed high nematicidal activity against all three nematode species, and nematicidal activity of dibromo(nitro)methane was discovered. These compounds could serve as new fumigation nematicides, pending further experiments.