Neem A Tree for Solving Global Problems (1992) / Chapter Skim
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2 The Reality
2 The Reality
Pages 15-22
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From page 15... ...
This is due in part to a lack of experience, in part to a lack of industrial interest (caused notably by the difficulty of patenting natural products) , and in part to a lack of laboratory data to substantiate the claims.
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From page 16... ...
Extracts from trees grown in different parts of the world currently show differing levels of activity, and the relative differences vary with the types of insects being tested. Sorting out just how genetics and environment not to mention handling methods and insect speciesinfluence neem's various ingredients is a knotty problem.
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From page 17... ...
in a barrel of water overnight, and use the resulting "neem tea" on their vegetable crops the next day. On the other hand, the isolation of individual neem ingredients is already being conducted in sophisticated factory settings in the United States.
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From page 18... ...
Instability When exposed to sunlight, neem products degrade and lose their pest-control properties. Typically, the crude extracts remain active for only eight days when exposed to the sun's ultraviolet rays.
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From page 19... ...
Indeed, there is evidence that they can affect certain aquatic life. Most studies with fish in laboratory tests have shown no deleterious effects, but in one trial both tadpoles and the mosquitoeating fish gambusia died when neem extracts were applied to the water.2 And neem seeds falling into fish ponds in Haiti killed tilapia 2 Jotwani and Srivastava, 1981.
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From page 20... ...
Although the end result may be more devastating than that from DDT, people used to seeing rapid knockdown may be initially disappointed, or even discouraged. This lack of quick effect poses a challenge for promoting neem in pest-control markets where people have come to expect instantaneous results.
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From page 21... ...
Recent reports suggest that it has severely damaged neem trees over large areas of northern Cameroon, Chad, northeastern Nigeria, and eastern Niger. It seems likely that this outbreak resulted from the stresses of a decade or more of drought in the Sahel, which has left many neems weak and sickly.4 Nonetheless, further devastating pest outbreaks are certainly possible.
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From page 22... ...
- There are also anecdotal accounts from West Africa of neem-leaf teas possibly causing kidney damage when taken over a long period. In other studies, neem extracts were found to be toxic to guinea pigs and rabbits,6 and leaves fed to goats and guinea pigs (5~200 mg per kg body weight)
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