Fungitoxicity of sodium n-methyldithio-carbamate (Vapam) and its decomposition products Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/t435gh31m

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • An assay for fungicidal activity of sodium N-methyldithiocarbamate (Na-MDC) and its decomposition products was developed in which there was a minimum influence due to the widely varying physical properties of the compounds (i.e. vapor pressure and water solubility). Decomposition of the toxicant during the tests was measured and held to a minimum. Tests were made against Fusarium oxysporum f. lycopersici (Sacc.) Snyd. & Hans. under aerobic and anaerobic conditions. Under anaerobic conditions Na-MDC gave a bimodal dosage response (DR) curve. Vapam, a commercial preparation of Na-MDC, failed to give bimodal DR curve although it did produce a two phase curve. Under aerobic conditions both forms of NaMDC gave straight line DR curves. Methyl isothiocyanate (MIT) produced identical DR curves under aerobic and anaerobic conditions, and thus, must have a different mode of fungicidal action from Na-MDC. There was no decomposition of Na-MDC or MIT during the test period so toxicity differences must be due to the action of the chemicals per se. N, N'-dimethylthiuram disulfide was highly fungitoxic and along with sodium trithiocarbonate, 2, 4-dimethyl-1, 2, 4-thiadiazolidine-3, 5-dithione and 4-methyl-5-methylimino-1, 2, 4-dithiazolidine-3-thione could account for the fungicidal effectiveness of Vapam. However, these compounds are not sufficiently volatile to explain the movement of the toxic principle from Vapam. Carbonyl sulfide, carbon disulfide, hydrogen sulfide, methylamine, N-N'-dimethylthiourea, and sulfur were not sufficiently fungicidal to account for the effectiveness of Vapam in plant disease control. Young spores from an acid culture medium were less susceptible to MIT in buffer than in water. When older cells from a basic culture medium were used the buffer increased the susceptibility of the cells to MIT. Although MIT is probably the main toxic agent from Vapam, this study shows that other decomposition products may contribute to its overall fungicidal activity.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 5.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Rejected by Katy Davis(kdscannerosu@gmail.com), reason: replace on 2014-04-30T19:24:25Z (GMT)
  • description.provenance : Submitted by Alex McFerrin (amscannerosu@gmail.com) on 2014-04-30T18:20:30Z No. of bitstreams: 1 ElsonJOsephE1966_Redacted.pdf: 737423 bytes, checksum: 8af8c1221ba2686219d1bb9745c4e368 (MD5)
  • description.provenance : Made available in DSpace on 2014-05-02T18:40:36Z (GMT). No. of bitstreams: 1 ElsonJosephE1966_Redacted.pdf: 737423 bytes, checksum: 8af8c1221ba2686219d1bb9745c4e368 (MD5) Previous issue date: 1965-12-14
  • description.provenance : Submitted by Alex McFerrin (amscannerosu@gmail.com) on 2014-04-30T19:30:25Z No. of bitstreams: 1 ElsonJosephE1966_Redacted.pdf: 737423 bytes, checksum: 8af8c1221ba2686219d1bb9745c4e368 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2014-04-30T19:31:06Z (GMT) No. of bitstreams: 1 ElsonJosephE1966_Redacted.pdf: 737423 bytes, checksum: 8af8c1221ba2686219d1bb9745c4e368 (MD5)
  • description.provenance : Approved for entry into archive by Katy Davis(kdscannerosu@gmail.com) on 2014-05-02T18:40:36Z (GMT) No. of bitstreams: 1 ElsonJosephE1966_Redacted.pdf: 737423 bytes, checksum: 8af8c1221ba2686219d1bb9745c4e368 (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items