14 April 2014
by Brett Aronson
The neem tree (Azadirachta indica) has been valued since antiquity. According to the book Neem: A Tree for Solving Global Problems, “the earliest Sanskrit medical writings refer to the benefits of its fruits, seeds, oil, leaves, roots, and bark.” This tree offers not only medicinal uses but can also be used for farming, fuel wood, food, or as an attractive ornamental.
Neem is a hardy and fast-growing tree which can reach between 15 to 20 meters in height. It is native to seasonally dry sub-tropical India, Pakistan, and Myanmar, where it has been used by humans for over two-thousand years. It has been introduced to and grows well throughout the world, including arid and semi-arid regions with dry and infertile soils, where it can tolerate drought. Neem trees can survive dry seasons seven to eight months long. The trees, however, don’t tolerate poorly-drained, water-logged soils.
The neem tree is known throughout the world for its effectiveness as a natural pesticide and specifically as a fungicide, nematicide, bactericide, and insecticide. It contains a chemical compound called azadirachtin, which can be extracted from its seeds and leaves and used to repel insects, as well as harm their digestive and reproductive properties.
According to the World AgroForestry Center, neem trees can be used as shade trees for livestock in hot climates or as a windbreak to reduce soil erosion and moisture loss and thus help increase production of other crops. Neem trees have been planted to rehabilitate degraded land in parts of Asia, Central America, and sub-Saharan Africa. Oil pressed from neem seeds can be used as protein-rich cattle and poultry feed or made into a nitrogen-rich neem-seed cake which can be applied to soils as a fertilizer.
For commercial cultivation, the neem tree is usually grown from seed or tip-cuttings in nurseries. However, cultivation from seed can be challenging since neem seeds are only viable for eight to ten days from collection. They can be quite difficult to propagate in nurseries, according to a report produced by the Winrock International Institute for Agricultural Development.
Neem has a variety of traditional medicinal uses. In East Africa, the leaf decoction has been used to treat malaria. The aromatic neem oil has been used to treat skin conditions, such as fungal infections, infected burns, and eczema, while the bark, leaves, and fruit have been used to make a bitter-tasting drink remedy for intestinal worms.
Neem oil, which is similar to other vegetable oils in composition, is used in cosmetics, hair products, soaps, and lotions, and is used especially in India. The wood has become increasingly valued for its use in furniture production while neem flowers produce a tasty honey. In India, neem shoots, leaves, and flowers are consumed in a soup-like dish or fried, seasoned, and served as an appetizer. In Southeast Asia, it is consumed by some people, but many find the leaves too bitter. In Myanmar, leaves and buds are boiled with tamarind to reduce the bitter flavor.
According to the World AgroForestry Center, “the market for neem-based pesticides is booming in India-growing by 7 to 9 percent annually–and Europe is expected to be the fastest growing market for the future.” Therefore it has the potential to be an important component of sustainable rural development programs.
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by Brett Aronson, International and Community Development Practitioner
Brett is a recent graduate from the Heller School at Brandeis University, where he studied Sustainable International Development. His interests include agricultural technologies and management practices that support sustainable livelihood development, food waste reduction strategies, culinary history, and the power of gardens and farms to bring communities together.