Research Papers: Nematicidal Activity of the Fungicide 2,3,4,5-Tetrachloronitrobenzene

Abstract

The fungicide 2,3,4,5-tetrachloronitrobenzene (TCNB) applied to Norfolk sandy loam at rates ranging from 0-0.1 g a.i./kg soil resulted in sharp declines in numbers of stunt (Tylenchorhynchus claytoni), lance (Hoplolaimus galeatus), root-knot (Meloidogyne incognita), dorylaimoid and saprophagous nematodes in soil planted to M-8 cotton; higher rates produced little additional effect. A similar pattern of reduction was observed for numbers of lance nematodes and the larvae of M. incognita in the root, number of galls/g root and the galling index. Numbers of lesion (Pratylenchus brachyurus) nematodes in the roots increased above those in the control in soils with 0.0125 g TCNB/kg soil; however, higher concentration reduced the numbers so that roots from soils with 0.1-0.5 g TCNB/kg contained few of these nematodes. Application of TCNB to soil resulted in a marked improvement in the appearance of the root systems.