VIEW ARTICLE

Detection of the Systemic Fungicide, Thiabendazole, in Cotton Plants and Soil by Chemical Analysis and Bioassay. D. C. Erwin, Department of Plant Pathology, University of California, Riverside 92502; J. J. Sims(2), D. E. Borum(3), and J. R. Childers(4). (2)(3)(4)Department of Plant Pathology, University of California, Riverside 92502. Phytopathology 61:964-967. Accepted for publication 12 March 1971. DOI: 10.1094/Phyto-61-964.

Thiabendazole, 2-(4-thiazolyl)benzimidazole, translocated from roots in treated soil to stems but was not always detected in leaves by the agar diffusion bioassay method. By analysis of plants utilizing ethyl acetate as extractant, thiabendazole was detected in roots, stems, and leaves, but the concentrations in upper parts of the plants were much less than in lower parts. By analysis of treated soil utilizing hot methanol, HCl, and ethyl acetate, 77% recovery of thiabendazole was obtained. A similar recovery was obtained by a bioassay method in which crude extracts of thiabendazole from soil were diluted in dimethylsulfoxide (DMSO) and delivered to a paper assay disc on agar. When soil from a treated field (35-40 ppm) was assayed by the DMSO extraction method, only a trace of Thiabendazole was detected after 2 months in the field.