Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-22T19:04:50.096Z Has data issue: false hasContentIssue false

Some Factors Which Influence the Toxicity of UHF Energy to Weed Seeds

Published online by Cambridge University Press:  12 June 2017

Robert P. Rice Jr.*
Affiliation:
Pest. Res. Center, Mich. State Univ., East Lansing, Mi 48824
Alan R. Putnam
Affiliation:
Pest. Res. Center, Mich. State Univ., East Lansing, Mi 48824
*
This is a portion of the senior author's thesis for the M.S. Degree.

Abstract

UHF energy (2450 MHz) was applied to seeds and seed-soil mixtures with a waveguide under controlled conditions. After treatment, seeds were germinated at 27 C to determine viability. Seeds were either killed or seedlings grew normally with no intermediate levels of inhibition typical of that produced with sub-lethal dosages of herbicides. The energy required to kill several species of dry seeds ranged from 88 to 183 J/cm2 and could be reduced 12 to 42% by a 24-hr imbibition period prior to treatment. When several seed-soil mixtures were treated, the greatest toxicity occurred in a moist muck and clay loam soil, with the least toxicity on a dry loamy sand soil. Although attenuation of activity occurred in dry soils of three types, less energy was required to kill seeds in moist soils than was required in the absence of soil. Increasing the power levels reduced the time of exposure necessary to kill barnyardgrass [Echinochloa crus-galli (L.) Beauv.] seeds. Less energy was required to kill seeds as the soil temperature was increased from −20 to +18 C.

Type
Research Article
Copyright
Copyright © 1977 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

1

Mich. Agric. Exp. Stn. Journal Article No. 7586.

References

Literature Cited

1. Davis, F.S., Wayland, J.R., and Merkle, M.G. 1971. Ultrahigh frequency electromagnetic fields for weed control: phytotoxicity and selectivity. Science 173:535537.Google Scholar
2. Davis, F.S., Wayland, J.R., and Merkle, M.G. 1973. Phytotoxicity of a UHF electromagnetic field. Nature 241:291292.Google Scholar
3. Heald, C.M., Menges, R.M., and Wayland, J.R. 1973. Effects of ultrahigh frequency electromagnetic energy on Rotylenchulus reniformis . Proc. Assoc. South Agric. Work (Abstr.). page 200.Google Scholar
4. Menges, R.M. and Wayland, J.R. 1974. UHF electromagnetic energy for weed control in vegetables. Weed Sci. 22:584590.Google Scholar
5. Wayland, J.R., Davis, F.S., Young, L.W., and Merkel, M.G. 1972. Effects of UHF fields on plants and seeds of mesquite and beans. J. Microwave Power 7:385388.Google Scholar
6. Wayland, J.R., Davis, F.S., and Merkle, M.G. 1973. Toxicity of an UHF device to plant seeds in soil. Weed Sci. 21:161162.Google Scholar
7. Wayland, J.R., Merkle, M., Davis, F., Menges, R.M., and Robinson, R. 1975. Control of weeds with UHF electromagnetic fields. Weed Res. 15:15.Google Scholar
8. Whatley, T.L., Wayland, J.R., Davis, F.S., and Merkle, M.G. 1973. Effects of soil moisture on phytotoxicity of microwave fields. Proc. South Weed Sci. Soc. 26:389 (Abstr.).Google Scholar
9. Whatley, T.L., Wayland, J.R., and Merkle, M.G. 1974. Factors affecting the phytotoxicity of a microwave field. Proc. South Weed Sci. Soc. 27:344 (Abstr.).Google Scholar