“Key Informant Survey” of Production, Value, Losses and ... - DfID

first day after application, and none more than 20% after ten days, but that some were superior at
intermediate times - at day three malation obtained over 80%, dipterex and parathion about 70%, and
sevin, BHC and DDT all less than 60%. In Pakistan, Farooq (unpub.) found dipterex best for cover
spray control of melon fly, attributing this to a slight attractant property, while studies in India found
that in bait sprays, while better than cypermethrin (which is slightly repellent) dipterex was less
effective than dichlorphos because the former, as stomach-acting, is slower in lethal infect than the
contact-action of the latter (Indian Institute of Horticultural Research, pers. comm.).
Botanical and non-conventional pesticides are widely favoured by farmers and consumers, as
(often) cheap or home-cultivable, less damaging to the environment and health of people and domestic
and beneficial organisms, and increasingly allowing certifiably “organic” cultivation with a large price
premium in discerning markets. A survey of organic bait and lure controls, largely from unpublished
sources, recommends tobacco and pyrethrum as lethal components (Stoll, 2000). Neem is widely used
and recommended in India - the plant grows easily along hedgerows and its properties are widely
known by farmers and extended by NGOs and extensionists. It has been successfully used against
pests of Cruciferae (Krishna Moorthy et al., 1998, 2000), Jassids and other sucking pests attacking the
early stages of bitter gourd (Soman et al., 1999) and produced successful fruit fly protection in guava,
jujube and cucurbits, as shown in Table II.4. It may not be a panacea, however. A farmer in Bihar
reported a small-scale student trial where neem control was inferior to that of synthetic chemicals, and
an apparent fertiliser effect deleteriously stimulated weed growth in neem-treated plots. It has also
been reported that neem’s disagreeable smell may discourage consumers - though perhaps not
seriously when set against synthetic chemicals and their need for preharvest intervals, which are of
growing concern among Indian consumers and farmers. Table II.4 also shows a less successful trial
outcome. The different outcomes of these trials offer many interpretations, perhaps because the fly
species and neem plant part and preparation may make considerable differences.
Table II.4. Percentage infestation of cucumbers by Bactocera cucurbitae with different cover
treatments (data from provisional experiments by IIHR) and of little gourd by Dacus ciliatus
with different cover treatments (Patel, 1994, mean of two seasons’ data).
B cucurbitae on cucumber D ciliatus on little gourd
Insecticide Infestation Insecticide Infestation
None 53 None 13
Neem cake 1 6 Fenthion 0.05 4
Neem kernel extract 2 9 Carbaryl 0.2 4
Pon cake 3 21 Endosulfan 0.07 8
Carbaryl 21 Monocrotofos 0.04 9
Nuvacron 21 Dichlorvos 0.05 7
Dimacron 23 Deltamethrin 0.001 7
Metacid 24 Triazophos 0.04 9
Neemark 4 0.3 11
1 - Dry neem cake after crushing for the extraction of oil, crumbled into the soil around the base of plants and covered with
soil.
2 - 75g of crushed kernel, soaked overnight in 1l water and filtered.
3 - Extract of Pongamia glabra, a local insecticidal plant.
4 - Commercial neem extract
Much farm-level fruit fly control depends on the attraction of flies to baits and lures, and
another question is whether neem, which has a slight repellent as well as insecticidal effect, may work
as the killing ingredient in these, or may repel flies and thus undermine attraction and mortality. Table
II.5 shows how on at least one fruit fly its effect as an oviposition deterrent is greater than as an
insecticide. At first glance it would therefore appear unsuitable, but this has never been actually tested,
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