SEE ALSO

• Neem based Insecticide:
  NeemAzal®-T/S

• Biological Control of Codling Moth:
  Madex®

• Organic Beekeeping Product:
  Thymovar®

The Neem Tree

“THE village pharmacy” — that is what people call the neem tree in India. For centuries people in that country have looked to the neem to provide relief from pain, fever, and infections. Believing that the neem can help purify their blood, many Hindus begin each year by eating a few neem leaves. People also clean their teeth with neem twigs, apply neem-leaf juice to skin disorders, and drink neem tea as a tonic. From time immemorial, Indians have considered the neem tree a miracle. Now, scientists around the world are beginning to share this opinion.

Its Role as a Tree

Found in tropical regions, the neem is a member of the mahogany family of trees. It grows up to 100 feet tall [30 m] and can achieve a girth of over 8 feet [2.5 m]. Since it is seldom leafless, it provides shade year-round. It grows quickly, requires little maintenance, and fares well in poor soil. In addition to providing year-round shade in hot climates, the neem can be used as firewood. Moreover, its termite-resistant wood is useful in construction and carpentry. So, judging solely on the basis of its usefulness as a tree, the neem does very well. But that is just the beginning.

Bugs Hate it

Because the people of India have long known that neem leaves repel troublesome insects, they place leaves in beds, books, bins, cupboards, and closets. In 1959 a German entomologist and his students became involved in neem research after witnessing a massive locust plague in the Sudan during which billions of locusts devoured the leaves of every tree except the neem.

Since then, scientists have learned that the neem's complex chemical arsenal is effective against more than 200 insect species as well as various mites, nematodes, fungi, bacteria, and even several viruses. In one experiment, researchers placed soybean leaves in a container with Japanese beetles. Half of each leaf had been sprayed with neem extracts. The beetles devoured the untreated halves of each leaf but didn't touch the treated portions. In fact, they died of starvation rather than eat even tiny portions of the treated leaves.

Such experiments suggest the possibility of developing an inexpensive, nontoxic, and easily prepared alternative to certain syntheticpesticides.In Nicaragua, for example, farmers mix pounded neem seed withwater-80 grams of seed per liter of water. They soak the pounded seed for 12 hours, strain out the seeds, and then spray the water on the crops.

Neem products do not kill most insects outright. Neem sprays alter an insect's life processes, so that eventually, it can no longer feed, breed, or metamorphose. But while neem products act against bugs, they do not appear to be harmful to birds, warm-blooded animals, or humans.

One of the applications that is of particular interest is the use of neem as a 'soft' pesticide that will allow people to protect crops in benign ways. The neem tree contains several compounds that have pesticidal properties - including Azadirachtin A...L, Salannin, Nimbin, Nimbidin and Meliantriol, etc.

These non—toxic compounds can be developed into natural pesticides that will drastically reduce environmental damage and residues.