Annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum) are significant weeds in Australian winter cropping systems. These species have developed significant herbicide resistance and new control strategies need to be developed. Microwave energy has been considered for weed control for some time. The research considered the effect of varying amounts of microwave energy on plants and their seeds for each species. Several experiments explored the interaction between microwave energy and seed depth in the soil. Plant responses to microwave energy were also determined for each species. Seed treatment requires higher energy applications than plant treatment and is conceptually similar to soil fumigation treatments. Soil treatment may have application in some high value horticultural crops, which already use soil fumigation. Microwave treatment of plants requires less energy, with wild radish requiring about 60 Jcm-2 to achieve 100% mortality, while ryegrass plants require about 370 Jcm-2 to achieve 100% mortality. Microwave treatment of growing plants can be compared to the application of herbicide. Therefore control of growing plants should be the focus of developing a commercially viable microwave weed control device for cropping systems.
McGillon T and Storrie A. Integrated weed management in Australian cropping systems - A training resource for farm advisors. CRC for Australian Weed Management: Adelaide, South Australia 2006.
Stanton R, Pratley J and Hudson D. Annual ryegrass control affected by choice of management system. In: Proceedings Cairns, Queensland, Australia 2008; 306-308.
Heap I. The international survey of herbicide resistant weeds. www.weedscience.com. (accessed 21 October 2013.
Brodie G. Derivation of a Cropping System Transfer Function for Weed Management: Part 1 – Herbicide Weed Management. Global Journal of Agricultural Innovation, Research & Development 2014; 1 (1): 11-16. http://dx.doi.org/10.15377/2409-9813.2014.01.01.2
Relyea RA. The Lethal Impact of Roundup on Aquatic and Terrestrial Amphibians. Ecological Applications 2005; 15(4): 1118-1124. http://dx.doi.org/10.1890/04-1291
Wickerham EL, Lozoff B, Shao J, Kaciroti N, Xia Y and Meeker JD. Reduced birth weight in relation to pesticide mixtures detected in cord blood of full-term infants. Environment International 2012; 47(0): 80-85. http://dx.doi.org/10.1016/j.envint.2012.06.007
Davis FS, Wayland JR and Merkle MG. Phytotoxicity of a UHF Electromagnetic Field. Nature 1973; 241(5387): 291- 292. http://dx.doi.org/10.1038/241291a0
Davis FS. New techniques in weed control via microwaves. In: Proceedings to Southern Nurserymen’s Association Conference. Nacogdoches Texas USA. 1974; 75-78.
Davis FS, Wayland JR and Merkle MG. Ultrahigh-Frequency Electromagnetic Fields for Weed Control: Phytotoxicity and Selectivity. Science 1971; 173(3996): 535-537. http://dx.doi.org/10.1126/science.173.3996.535
Brodie G, Ryan C and Lancaster C. Microwave technologies as part of an integrated weed management strategy: a review. International Journal of Agronomy 2012. http://dx.doi.org/10.1155/2012/636905
Vidmar M. An improved microwave weed killer. Microwave Journal 2005; 48(10): 116-126.
Nelson SO. A review and assessment of microwave energy for soil treatment to control pests. Überblick und Beurteilung des Einsatzes von Mikrowellenenergie zur Schädlingsbekämpfung in Böden 1996; (1): 281.
Sartorato I, Zanin G, Baldoin C and Zanche C. Observations on the potential of microwaves for weed control. Weed Research 2006; 46(1): 1-9. http://dx.doi.org/10.1111/j.1365-3180.2006.00484.x
Brodie G. The influence of load geometry on temperature distribution during microwave heating. Transactions of the American Society of Agricultural and Biological Engineers 2008; 51(4): 1401-1413.
Cronin NJ. Microwave and Optical Waveguides. J W Arrowsmith Ltd: Bristol 1995.
Nikolova NK. Modern Antennas in Wireless Telecommunications. http://www.ece.mcmaster.ca/faculty/nikolova/antennas.htm. (accessed 5th of August, 2013).
Velazquez-Marti B, Gracia-Lopez C and Plaza-Gonzalez PJ. Determination of dielectric properties of agricultural soil. Biosystems Engineering 2005; 91(1): 119-125. http://dx.doi.org/10.1016/j.biosystemseng.2005.02.004
Von Hippel AR. Dielectric Materials and Applications. M.I.T. Press: Cambridge 1954.
Shen JB, Xu LY, Jin XQ, Chen JH and Lu HF. Effect of temperature regime on germination of seed of perennial ryegrass (Lolium perenne). Grass and Forage Science 2008; 63(2): 249-256. http://dx.doi.org/10.1111/j.1365-2494.2008.00630.x
Brodie G, Jacob MV, Sheehan M, Yin L, Cushion M and Harris G. Microwave modification of sugar cane to enhance juice extraction during milling. Journal of Microwave Power and Electromagnetic Energy 2011; 45(4): 178-187.
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