title: Spot drip application of dimethyl disulfide as a post-plant treatment for the control of plant parasitic nematodes and soilborne pathogens in grape production.
abstract: BACKGROUND
  Plant parasitic nematodes and soilborne pathogens can reduce the overall productivity in grape production. Not all grape growers apply soil fumigants before planting, and there is no single rootstock resistant to all nematode species. The aim of this investigation was to evaluate the effect of dimethyl disulfide (DMDS) applied at 112, 224, 448 and 897 kg ha(-1) as a post-plant treatment against soilborne plant parasitic nematodes and pathogens on the grape yield in established grapevines.
  
  
  RESULTS
  In microplot and field trials, post-plant fumigation with DMDS controlled citrus (Tylenchulus semipenetrans), root-knot (Meloidogyne spp.), pin (Paratylenchus spp.) and ring (Mesocriconema xenoplax) nematodes in established Thomson Seedless grapevines. However, DMDS did not control the soilborne pathogens Pythium ultimum and Fusarium oxysporum. No indications of phytotoxicity were detected after post-plant fumigation with DMDS. In the field trial, grape yield was significantly higher with the lowest DMDS rate, but no difference among other rates was observed in comparison with the untreated control.
  
  
  CONCLUSIONS
  Post-plant fumigation with DMDS controlled plant parasitic nematodes in established grapevines but was less efficacious against soilborne pathogens. Low rates of DMDS were sufficient for nematode control and increased the grape yield, probably without affecting beneficial soil organisms. Further research on evaluating the potential effect of DMDS against beneficial soil organisms is needed.
authors.affiliation: US Department of Agriculture, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Water Management Research Unit, Parlier, CA, 93648, USA; Department of Environmental Sciences, University of California, Riverside, CA, USA.
authors.forename: J Alfonso
authors.initials: JA
authors.lastname: Cabrera
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: James S
authors.initials: JS
authors.lastname: Gerik
authors.forename: Jay
authors.initials: J
authors.lastname: Gan
mesh_terms: D000818:Animals; D000969:Antinematodal Agents; D004220:Disulfides; D005651:Fumigation; D005659:Fungicides, Industrial; D005670:Fusarium; D010935:Plant Diseases / Q000517:prevention & control*; D011775:Pythium; D017187:Tylenchida; D027843:Vitis / Q000254:growth & development
chemical_list: D000969:Antinematodal Agents; D004220:Disulfides; D005659:Fungicides, Industrial; C021181:dimethyl disulfide
keywords: Fusarium oxysporum; Meloidogyne spp; Mesocriconema xenoplax; Paladin; Paratylenchus spp; Pythium ultimum; Tylenchulus semipenetrans; dimethyl disulfide; spot fumigation