Environmental Engineering Reference
In-Depth Information
alternatives are under trial. A few are commercially available. One is a bio-pesticide called 'Havana',
which contains Azadirachtin at 0.15%, an extract from Indian neem (
Azhadiracta indica
). This has
been recommended by the manufacturer for use in place of carbofuran as an insecticide/nematicide.
However, it is much more expensive (130 rupees per kilogram or 3 USD per kilogram) when com-
pared to carbofuran (65 to 80 rupees per kilogram or 1.5 to 2 USD per kilogram). Other compounds
such as lantanoside, linaroside and camarinic acid, which are isolated from the aerial parts of
Lantana
camara
(a fl owering plant in the verbena family), were also tested for nematicidal activity against
the root knot nematode (
Meloidogyne incognita
). They were found to be 90, 85 and 100% effective
respectively at a 1.0% concentration (Begum, Wahab, Siddiqui et al. 2000). Such results are compa-
rable to those obtained using Furadan (i.e., 100% mortality at a 1.0% concentration).
Experiments have also revealed that other bio-agents such as
Paecilomyces lilacinus
and
Trichoderma viride
(both naturally-occurring fungi), along with mustard oil cake, were effective in
controlling root knot nematode to an extent comparable with Furadan (Goswami, Pandey, Ratour
et al. 2006). Another bio-agent (and fungi)
Trichoderma harzianum
, was more effective than
Furadan in controlling the root knot nematode in patchouli, an oil-yielding plant (Pandey, Kalra,
Gupta et al. 2009). Certain products (Bionematon, Yorker, Trichostar, Tricho guard, Bioderma and
Ecoderma) containing these bio-agents are now available on the Indian market for commercial use.
Other promising bacterial biological agents with nematicidal activity are
Pseudomonas fl uorescens
and
Pasteuria penetrans
(Khan 2008). However, farmers remain reluctant to switch to these alterna-
tives, in particular because they fi nd compounds such as carbofuran to be highly effective.
In Hawaii, experiments have been undertaken to control banana root borer (
Cosmopolites sor-
didus
) biologically, using predatory beetles (
Plaesius
javanus
and
Dactylosternus hydrophiloides
).
However, results were disappointing. Hence, Furadan is recommended as the only option for com-
mercial farms there (Mau and Martin 2007). It is available only to licensed users, and no other
alternative insecticide has been registered for use in Hawaii for this pest (Mau and Martin 2007).
As far as chemical pesticides are concerned, phorate is the nearest substitute available for carbo-
furan. Both are available in granular form, and they are often used in combination. They are both
referred to as 'kurunai' (meaning granules) by local farmers in the Nilgiris District of Tamil Nadu.
Phorate is available in a 10% (10 G) composition, and was more effective in controlling cut worm
attacks on
Paulownia fortune
plants when compared to Furadan (Singh and Kumar 2006). However,
phorate is even more harmful and is classifi ed as 'Extremely Hazardous' while carbofuran comes
under the 'Highly Hazardous' category as per the 2004 World Health Organisation (WHO) recom-
mendations. Moreover, phorate formulations have been linked with several cases of intentional poi-
soning in India (refer to Table 4.7). Thus, in our opinion, phorate probably currently poses a greater
problem than carbofuran in India.
4.10.2 Should carbofuran be banned in India?
Given the extent to which carbofuran is currently used as a nematicide/insecticide in India, there
is trepidation with regard to banning it here. Crop varieties that offer the highest yield (which are
required to meet the increasing demand for food within India) cannot be cultivated without the use
of potent pesticides since their resistance to pests has now been lowered. While alternatives to car-
bofuran are under trial, and a few products have been introduced onto the market, farmers remain
unconvinced that these offer effective and economical pest control. Farmers will never shift to bio-
pesticides as long as carbofuran is available (especially at a lower cost), or until they are convinced
that the substitute performs better than carbofuran. At this point in time, chemical equivalents to
carbofuran are not available. Substitutes like phorate are even more hazardous and should perhaps be
banned before carbofuran. Nevertheless, the harmful effects of carbofuran, not only as a poison but
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