Submitted to: Encyclopedia of Agrochemicals
Publication Type: Review Article
Publication Acceptance Date: June 5, 2002
Publication Date: September 1, 2003
Citation: Chitwood, D. J. 2003. Nematicides. In: Plimmer, J. R., editor. Encyclopedia of Agrochemicals. Vol. 3. New York, NY: John Wiley & Sons. p. 1104-1115. Interpretive Summary: Plant-parasitic nematodes are microscopic soil worms that annually cause crop losses in the United States of $10 billion. Historically, control of crop damage caused by nematodes has relied upon the use of chemicals called nematicides. A major problem currently facing growers is that the number of available nematicides has declined in the past 20 years because of environmental problems associated with the use of the now-prohibited compounds. This review article briefly describes the history of nematicide research, the different types of chemicals available to growers for nematode control, and the formulations and application techniques utilized by growers in order to maximize nematode control and eliminate possible environmental contamination. The review also describes research developing new kinds of chemical control measures for nematodes, such as naturally occurring plant or animal products, as well as new types of synthetic chemicals that degrade into harmless materials already present in soil. This review will be useful to scientists developing novel methods for nematode control; such research will eventually benefit the public by providing safer methods for reducing crop losses caused by nematodes.
Technical Abstract: Few chemical nematicides remain registered for agronomic use because of the deregistration of many soil fumigants. The major chemical nematicides presently available include 1,3-dichloropropene, metam sodium, methyl bromide, aldicarb, oxamyl, ethoprop and fenamiphos. Most of these may face additional future restrictions. Various formulations and application techniques are utilized in order to maximize nematicidal efficacy and minimize environmental contamination. Although resistance of plant-parasitic nematodes to chemical nematicides in agricultural fields is insignificant, in some cases enhanced microbial degradation reduces nematicidal effectiveness. Two biopesticidal nematicides are registered in the United States: a chitinous material and a plant extract. Future control of phytoparasitic nematodes will involve increased use of nonchemical, sustainable or site-specific management tactics. Fumigants receiving increased research attention as methyl bromide alternatives include the registered sodium tetrathiocarbonate and the unregistered methyl iodide and propargyl bromide. In addition,phytochemicals and other biorational chemicals are providing leads for discovering future nematicides. Future implementation of safe and effective chemical nematode management will be challenging.