The efficacy of furfural (2-furfuraldehyde) as a nematicide was studied in greenhouse and microplot experiments. Mixing furfural with soil at rates of 0.1-1.0 ml/kg prior to transferring soil to greenhouse pots suppressed initial populations of Meloidogyne arenaria and Pratylenchus brachyurus. The number of root galls induced by Meloidogyne arenaria in 'Summer Crookneck' squash (Cucurbita pepo) after 8 weeks was reduced proportionately to the rate of furfural applied to the soil before planting. Similar results were obtained for M. incognita, Heterodera glycines, and other species when soybean (Glycine max) was used as a host. Furfural also was effective as a nematicide when its vapor was allowed to diffuse through a soil column. In microplots, preplant injection of furfural was simulated by pouring it into a 25-cm-deep trench that was immediately covered with soil. When furfural was applied to microplots at rates of 53-159 ml/m soil, initial populations of M. arenaria and P minor we
