Evaluation of Nematicidal Activity of Fluensulfone against Non-Target Free-Living Nematodes under Field Conditions

Abstract

The use of nematicides with reduced toxic side-effects against non-target free-living nematodes is a favorable option for farmers to control plant-parasitic nematodes. The nematicide fluensulfone was registered in several countries for the control of the root-knot nematodes, Meloidogyne spp. among other plant-parasitic nematodes. This study aimed to evaluate the nematicidal activity of fluensulfone against non-target nematode fauna in four field experiments, each under different conditions (soils types and plant hosts). Nematodes extracted from soil samples were classified and counted based on their morphological characters. Fluensulfone significantly reduced damage caused by root-knot nematodes to tomato and sweet potato plants, while overall non-target free-living nematode population densities were maintained at the same level as those in control. Different diversity indices (e.g., Shannon-Wiener H’, Simpson’s D, species richness, evenness J’, maturity indices) and principal component analyses in the four experiments showed that fluensulfone treatment kept a similar diversity level of non-target free-living nematode fauna to that of the non-treated control. The results suggested that fluensulfone may have minimal impact to free-living nematode fauna in both population density and diversity when the nematicide was applied to control Meloidogyne spp.