Skip to main content Accessibility help

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

  • Robert P. Rice (a1) and Alan R. Putnam (a1)


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.


Corresponding author

This is a portion of the senior author's thesis for the M.S. Degree.


Hide All

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



Hide All
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.
2. Davis, F.S., Wayland, J.R., and Merkle, M.G. 1973. Phytotoxicity of a UHF electromagnetic field. Nature 241:291292.
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.
4. Menges, R.M. and Wayland, J.R. 1974. UHF electromagnetic energy for weed control in vegetables. Weed Sci. 22:584590.
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.
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.
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.
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.).
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.).


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed