Allelochemicals Biologica... - Name

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resulted in lower egg parasitism by the fungus (Siddiqui and Shaukat, 2003).
4.3. Furfural
The biological activity of furfural (also known as 2-furancarboxaldehyde, furaldehyde;
2-furanaldehyde, 2-furfuraldehyde, fural, furfurol) has also been recognized for decades
(Flor, 1926). Furfural is the aldehyde of pyromucic acid and has properties similar to
those of benzaldehyde. Furfural is a derivative of furan and is prepared commercially
by dehydration of pentose sugars obtained from sugarcane, cornstalks and corncobs,
husks of oat and peanut, and other agricultural waste products (Harborne and Baxter,
1993). Commercially available products for disease and nematode control are available
in several countries including the United States. These products include Multiguard
FFA (furfural (75%) + allyl isothiocynate (25%), Harborchem, Cranford, New Jersey),
and Multiguard Protect (furfural (50%) + metham sodium (50%), Harborchem,
Cranford, New Jersey).
Rajendran et al. (2003) reported improved plant growth and reductions in soil
populations of M. arenaria and R. reniformis in groundnut with formulations of furfural
compared to an untreated control, with no effect on free-living nematodes in soil.
Spaull (1997) also found that free-living nematodes were relatively unaffected by
furfural application while parasitic nematodes differed in their susceptibility with
species of Paratichodorus and Xiphinema being more susceptible than Helicotylenchus
and Tylenchorhynchus. Sipes (1997) found furfural to be as effective as 1,3-D for
reduction of preplant soil nematode populations in pineapple production. Rodríguez-
Kábana et al. (1993) found that furfural was an effective nematicide against M.
arenaria, M. incognita, Heterodera glycines, and Pratylenchus spp. on squash, okra,
and soybean. Furfural reduced populations of M. incognita in field microplots with
no phytotoxicity to cotton at 0.18 -2.14 ml/kg soil (Bauske et al., 1994).
4.4. Thymol
NANCY KOKALIS-BURELLE AND RODRÍGO RODRIGUEZ-KÁBANA Thymol (isopropyl-m-cresol) is a volatile, phenolic monoterpene produced by several
plants including thyme (Thymus vulgaris L.) (Baerheim Svendsen and Scheffer, 1985).
Thymol has well-known antiseptic, antifungal, and anthelminthic properties (Wilson
et al., 1977) and is also used for food and fragrance applications (Bauer et al., 1990).
Research by Soler-Serratosa et al. (1996) using combinations of thymol and
benzaldehyde for root-knot and cyst nematode control on soybeans showed that both
compounds exhibited wide spectrum nematicidal activity with Meloidogyne spp. and
Dorylaimid nematodes being more sensitive than cyst nematode and nonparasitic
nematodes (Soler-Serratosa et al., 1996). In addition to the direct toxicity of these
compounds to nematodes, it was hyopothesized that stimulation of beneficial microflora
by the compounds or their products, altered host response, and a deleterious physicochemical
environment may all contribute to reduced gall formation (Soler-Seratosa et
al., 1996).