Stan Goodman said:
On Mon, 17 May 2004 09:52:39 UTC, (Pat Kiewicz)
opined:
-use Neem extracts on plants (will kill larvae before they pupate; don't remove
infested leaves)
What may this be? Sounds like a trade name. Not everything is marketted
everywhere.
The Neem tree (Azadirachta indica) is native to India. It is marketed under
various names, but generally the active ingredient will be described as
'Neem oil' or as 'Azadirachtin.'
/begin quoted material/
"What's in a Neem?"
Finally, a nature program on TV that has featured a good old, sedentary,
not-fuzzy-and-cute, cold-blooded plant, the neem tree (Azadirachta indica).
CBC's The Nature of Things devoted a full hour to discussing the current and
possible uses of this tropical tree. This native of India is a very good plant for
growing in hot dry areas on poor soils, and it has been spread by humans to
various areas in Africa, the Middle East and the Caribbean. In India almost every
village has its neem tree and the villagers call it their "village pharmacy". There
is a use for all parts of the tree [to repel insects, to treat skin infections, to kill
internal parasites, to treat fevers, to clean teeth, as a contraceptive, etc.].
Neem tree seeds can be processed to produce neem oil and neem cake [solid
residue]. Neem cake is used as a fertilizer (it is said to improve nutrient uptake
by plants and to repel insects in the soil) and can be fed to livestock (it combats
intestinal parasites). A major use of neem oil in India is in the manufacture of
soaps, toothpaste and other toiletries [such products are now being sold in
Germany and other countries]. The effect of neem oil and of aqueous extracts of
neem cake on insects has attracted the attention of large chemical companies.
Concerted efforts are under way to synthesize the main active ingredient,
azadirachtin, which can act [with remarkable specificity to insects] in several
ways. It is an antifeedant, causing insects to stop feeding on whatever the
compound is sprayed on. It can also act as a hormonal substance, interfering
with the normal development of the insect [there are problems with molting to
produce the adult reproductive stage]. Both effects would enable third world
grain producers to combat the massive losses of stored grain that currently
occur. A small amount of neem oil sprayed on the stored grain is effective in
deterring feeding by bruchid beetles [major destroyers of stored grain].
Aflatoxins, potent carcinogens causing liver cancer in humans eating certain
seeds infected with two species of Penicillium, could be controlled by the neem
extract. Experiments with cotton show that the neem extract prevents the
seed-infecting fungi from producing the aflatoxins. There is one problem with
the neem extract, however. It is unstable with respect to heat and light. For
those of you who did not view this program, a research team from U.B.C. which
was featured on the program has published an excellent review of neem tree usage
in the Canadian Journal of Botany [86(1): 1-11, 1990].
The Nature of Things, CBC-TV, December 1, 1993
--
Pat in Plymouth MI ('someplace.net' is comcast)
Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)