How to Grow Neem Trees
Neem in Short
- WHAT SORT OF SOIL SUITS THE NEEM ?
The Neem grows on almost all types of soils including clayey, saline and alkaline soils, with pH upto 8.5, but does well on black cotton soil and deep, well-drained soil with good sub-soil water. Unlike most other multipurpose tree species, it thrives well on dry, stony, shallow soils and even on soils having hard calcareous or clay pan, at a shallow depth. The tree improves the soil fertility and water-holding capacity as it has a unique property of calcium mining, which changes the acidic soils into neutral.
- HOW MUCH WATER DOES IT NEED ?
Neem tree needs little water and plenty of sunlight. The tree grows naturally in areas where the rainfall is in the range of 450 to 1200 mm. However, it has been introduced successfully even in areas where the rainfall is as low as 200 – 250 mm. It cannot withstand water-logged areas and poorly drained soils. Neem makes land more fertile
- HOW LONG DOES IT TAKE TO REACH MATURITY ?
The Neem grows slowly during the first year of planting. Young neem plants cannot tolerate intensive shade, frost or excessive cold. A Neem tree normally begins to bear fruit between 3 and 5 years and becomes fully productive in 10 years. A mature tree produce 30 – 50 kg. fruit every year
- HOW LONG DOES THE TREE LIVE ?
It is estimated that a Neem tree has a productive life span of 150 – 200 years
- WHERE CAN I GET THE SEED / SAPLING ?
- HOW TO PLANT NEEM TREES ?
The seeds should be as fresh as possible as older seeds often do not germinate. Provided that only a few trees are to be planted, and there is sufficient moisture available, with minimum weeds, the seeds may be sown directly into the ground. Two to three seeds are placed together about 1 cm deep in loose soil. After germination, only the strongest plant should be retained. When planting a large number, it is advisable to cultivate young plants first in pots, trays or plastic bags. After 3 months, they should be transplanted into the ground. When using bags or pots care should be taken that the plants are not allowed to develop to a stage where the tap root has pierced the bottom and has to be shortened before transplantation. This weakens the trees and substantially slows their growth.
En: neem, Indian lilac, Fr: azadira d'Inde, margousier, azidarac, azadira Pt: margosa (Goa) Es: margosa, nim De: Niembaum Hindi: neem, nimb Burmese: tamar, tamarkha Urdu: nim, neem Punjabi: neem Tamil: vembu, veppan Sanskrit: nimba, nimbou, arishtha (reliever of sickness) Sindhi: nimmu Sri Lanka: kohomba Farsi: azad darakht i hindi (free tree of India), nib Malay: veppa Singapore: kohumba, nimba Indonesia: mindi Nigeria: dongoyaro Kiswahili: mwarubaini (muarobaini)
Neem is a member of the mahogany family, Meliaceae. It is today known by the botanic name Azadirachta Indica A. Juss. In the past, however, it has been known by several names, and some botanists formerly lumped it together with at least one of its relatives. The result is that the older literature is so confusing that it is sometimes impossible to determine just which species is being discussed.(Previous botanic names were Melia indica and M. azadirachta. The latter name (not to mention neem itself) has sometimes been confused with M. azedarach, a West Asian tree commonly known as Persian lilac, bakain, dharak, or chinaberry. The taxonomy of all these closely related species is so complex that some botanists have recognized as many as 15 species; others, as few as 2.)
Uses of the Neem Tree and seeds
The neem tree is a robust tree vartiety growing in a wide range of climates, from tropical to arid climates and can therefore be used for reforestation purposes. Neem has more than 100 unique bio-active compounds, which have potential applications in agriculture, animal care, public health, and for even regulating human fertility. The seeds are used in different forms for their very powerful insecticide effect on a wide range of pests and their armlessness ( at this stage of knowledge) for warmblooded animals and mammals. It can also be used against mosquito proliferation, as insect reppellent and to protect crops agains locusts infestations. Different preparations are used for various medicinal purposes among which contraceptive effect is being researched about. See the article: What to Do with Neem Seeds
Neem trees are attractive broad-leaved evergreens that can grow up to 30 m tall and 2.5 m in girth. Their spreading branches form rounded crowns as much as 20 m across. They remain in leaf except during extreme drought, when the leaves may fall off. The short, usually straight trunk has a moderately thick, strongly furrowed bark. The roots penetrate the soil deeply, at least where the site permits, and, particularly when injured, they produce suckers.
This suckering tends to be especially prolific in dry localities.
Neem can take considerable abuse. For example, it easily withstands pollarding (repeated lopping at heights above about 1.5 m) and its topped trunk resprouts vigorously. It also freely coppices (repeated lopping at near-ground level). Regrowth from both pollarding and coppicing can be exceptionally fast because it is being served by a root system large enough to feed a full-grown tree.
The small, white, bisexual flowers are borne in axillary clusters. They have a honeylike scent and attract many bees. Neem honey is popular, and reportedly contains no trace of azadirachtin.
The fruit is a smooth, ellipsoidal drupe, up to almost 2 cm long. When ripe, it is yellow or greenish yellow and comprises a sweet pulp enclosing a seed. The seed is composed of a shell and a kernel (sometimes two or three kernels), each about half of the seed's weight. It is the kernel that is used most in pest control. (The leaves also contain pesticidal ingredients, but as a rule they are much less effective than those of the seed.)
A neem tree normally begins bearing fruit after 3-5 years, becomes fully productive in 10 years, and from then on can produce 30- to 100kg of fruits annually, depending on rainfall, insolation, soil type, and ecotype or genotype.It may live for more than two centuries.
Fifty kg of fruit yields 30kg of seed, which gives 6kg of oil and 24kg of seed cake.
Neem is thought to have originated in Assam and Burma (where it is common throughout the central dry zone and the Siwalik hills). However, the exact origin is uncertain: some say neem is native to the whole Indian subcontinent; others attribute it to dry forest areas throughout all of South and Southeast Asia, including Pakistan, Sri Lanka, Thailand, Malaysia, and Indonesia.
It is in India that the tree is most widely used. It is grown from the southern tip of Kerala to the Himalayan hills, in tropical to subtropical regions, in semiarid to wet tropical regions, and from sea level to about 700 m elevation.
As already noted, neem was introduced to Africa earlier this century. It is now well established in at least 30 countries, particularly those in the regions along the Sahara's southern fringe, where it has become an important provider of both fuel and lumber. Although widely naturalized, it has nowhere become a pest. Indeed, it seems rather well "domesticated": it appears to thrive in villages and towns.
Over the last century or so, the tree has also been established in Fiji, Mauritius, the Caribbean, and many countries of Central and South America. In some cases it was probably introduced by indentured laborers, who remembered its value from their days of living in India's villages. In other cases it has been introduced by foresters. In the continental United States, small plantings are prospering in southern Florida, and exploratory plots have been established in southern California and Arizona.
The tree is easily propagated - both sexually and vegetatively. It can be planted using seeds, seedlings, saplings, root suckers, or tissue culture. However, it is normally grown from seed, either planted directly on the site or transplanted as seedlings from a nursery.
The seeds are fairly easy to prepare. The fruit drops from the trees by itself; the pulp, when wet, can be removed by rubbing against a coarse surface; and (after washing with water) the clean, white seeds are obtained. In certain nations - Togo and Senegal, for example - people leave the cleaning to the fruit bats and birds, who feed on the sweet pulp and then spit out the seeds under the trees.
It is reputed that neem seeds are not viable for long. It is generally considered that after 2-6 months in storage they will no longer germinate. However, some recent observations of seeds that had been stored in France indicated that seeds without endocarp had an acceptable germinative capacity (42 percent) after more than 5 years.(Information from Y. Roederer and R. Bellefontaine. Refrigeration is also said to extend the viability.) According to the Forest, Farm, and Community Tree Network (FACT Net),the viability of fresh seed decreases rapidly after two weeks, and improperly stored seeds have low germination rates. Ripe seed should be collected from the tree and processed immediately. First the pulp is removed and the seeds are washed clean. Seeds are air dried for 3-7 days in the shade, or until the moisture content is about 30%. They can then be stored for up to four months if kept at 15°C. Seed will remain viable even longer if dried to 6-7% moisture content and refrigerated in sealed containers at 4° C.
They recommend to sow seed in nursery beds in rows 15-25 cm apart, and 2.5-5 cm spacing within the rows. Seedlings can be pricked out when two pairs of leaves have developed (1-2 months), or the rows should be thinned to 15 cm x 15 cm spacing. Plastic pots are commonly used to produce neem seedlings, although rigid container systems are used in Haiti with success. Seeds should be sown horizontally at a depth of 1 cm. Fresh seeds will have the highest germination rate, and seedlings will emerge within in 1-3 weeks. Removal of the seed coat may increase germination rates for stored seeds. Both bare-root and containerized seedlings should be raised under partial shade for the first 1-2 months, or until about 30 cm tall, then gradually exposed to full sunlight.
Bare-rooted seedlings are usually kept in the nursery for 1-2 years before outplanting. The roots and shoots of seedlings lifted from nursery beds should be pruned before transplanting. Bare-rooted seedlings can also be prepared for stump planting. Stumps are made from 1-2 year old seedlings by trimming the root to 20-22 cm root and the shoot to 5 cm. Containerized seedlings should be outplanted after 3-4 months in the nursery, when they reach 30-50 cm. Fuelwood plantations are laid out at a 2.5 m x 2.5 m spacing, and then later thinned to 5 m x 5 m. The recommended spacing for windbreaks is 4 m x 2 m. Neem trees managed to maximize fruit yield should be more widely spaced to allow the crown to develop fully.
The tree is said to grow "almost anywhere" in the lowland tropics. However, it generally performs best in areas with annual rainfalls of 400-1,200 mm. It thrives under the hottest conditions, where maximum shade temperature may soar past 50°C, but it will not withstand freezing or extended cold. It does well at elevations from sea level to perhaps 1,000 m near the equator. The taproot (at least in young specimens) may be as much as twice the height of the tree.
Neem is renowned for good growth on dry, infertile sites. It performs better than most trees where soils are sterile, stony, and shallow, or where there is a hardpan near the surface. The tree also grows well on some acid soils. Indeed, it is said that the fallen neem leaves, which are slightly alkaline (pH 8.2), are good for neutralizing acidity in the soil. On the other hand, neem cannot stand "wet feet," and quickly dies if the site becomes waterlogged.
Neem often grows rapidly. It can be cut for timber after just 5-7 years. Maximum yields reported from northern Nigeria (Samaru) amounted to 169 m3 of fuelwood per hectare after a rotation of 8 years. Yields in Ghana were recorded between 108 and 137 m3 per hectare in the same time.
Weeds seldom affect growth. Except in the case of very young plants, neem can dominate almost all competitors. In fact, the trees themselves may become "weeds." They spread widely under favorable site conditions, since the seeds are distributed by birds, bats, and baboons. For the same reason, natural regeneration under old trees is often abundant. But for all that, in virtually every place it grows neem is considered a boon, not a bane. People almost always like to see more neems coming up.
Neem is renowned for its robust growth and resilience to harsh conditions, but, like all living things, it has various shortcomings, some of which are discussed below.
By and large, most neem trees are reputed to be remarkably pest free; however, in Nigeria
14 insect species and I parasitic plant have been recorded as pests. Few of the attacks were serious, and the trees almost invariably recovered, although their growth and branching may have been affected.
However, in recent years a more serious threat has emerged. In some parts of Africa (mainly in the Lake Chad Basin), a scale insect (Aonidiella orientalis) has become a serious pest. This and other scale insects sometimes infest neem trees in central and south India. They feed on sap, and although they do little harm to mature trees, they may kill young ones. Now that one type has been detected in Africa, the impact could be severe. (It has been suggested that a drastic lowering of the groundwater level around Lake Chad - which nearly dried out during a drought in the Sahel - was the main reason for the outbreak. This is perhaps true; scale insects are usually "secondary" pests that multiply best on plants that are already damaged by other pests or other adverse environmental factors.)
Other insect pests include the following:
· The scale insect Pinnaspis strachani (very common in Asia, Africa, and Latin America);
· Leaf-cutting ants Acromyrmex spp. (common defoliators of young neem trees in Central and South America);
· The tortricid moth Adoxophyes aurata (attacks leaves in Asia including Papua New Guinea);
· The bug Helopeltis theivora (considered a serious neem pest in southern India); and
· The pyralid moth Hypsipyla sp. (attacks neem shoots in Australia).
Even though neem timber is renowned for termite resistance, termites sometimes damage, or even kill, the living trees. They usually attack only sickly specimens, however.
Despite the fact that the leaves contain fungicidal and antibacterial ingredients, certain microbes may attack different parts of the tree, including the following:
· Roots (root rot, Ganoderma lucidum, for instance);
· Stems and twigs (the blight Corticium salmonicolor, for example);
· Leaves (a leaf spot, Cercospora subsessilis; powdery mildew, Oidium sp., and the bacterial blight Pseudomonas azadirachtae);(5) and
· Seedlings (several blights, rots, and wilts - including Sclerotium, Rhizoctonia, and Fusarium).(6)
A canker disease that discolors the wood and seems to coincide with a sudden absorption of water after long droughts has also been observed.
A lack of zinc or potassium drastically reduces growth. Trees affected by zinc deficiency show chlorosis of the leaf tips and leaf margins, their shoots exude much resin, and their older leaves fall off. Those with potassium deficiency show leaf tip and marginal chlorosis and die back (necrosis).
Fire kills neem seedlings outright. However, mature trees almost always regrow, especially if the dead parts are quickly cut away.
High winds are a potential problem. Large trees frequently snap off during hurricanes, cyclones, or typhoons. Neem is therefore a poor candidate for planting in areas prone to such violent storms.
Seedlings regenerating beneath stands of neem are sensitive to sudden exposure to intense sunlight. Thus, clear-felling neem trees normally produces a massive seedling kill, especially if the seedlings are small.
In some localities rats and porcupines kill young trees by gnawing the bark around the base. Even when not causing any physical damage, rodents can be pests: wherever they are numerous, the fruits may disappear before the farmer can harvest them.
Neem, with its intensely bitter foliage, is not a preferred browse, but if nothing else is available goats and camels will eat it. In fact, in Asia goats and camels have been known to browse young neem trees so severely in times of scarcity that the plants died. In Africa neem is generally ignored by livestock (which makes the tree easy to establish even within villages and courtyards). The reason that livestock treat neem differently in Asia and Africa is unknown at present. It may be differences in the tree specimens, or in the animals' preferences or past experiences.
- How to Grow Neem Trees
- What to Do with Neem Seeds
- How to Use Neem as a Natural Pesticide
- How to Process Oilseed on a Small Scale
- How to Control Termite without Chemicals
- How to Process Oilseed on a Small Scale
- How to Use Garlic as a Natural Pesticide
- How to Use Chillies as a Natural Pesticide
- How to Grow Shea Trees (Karité, Nku, Bambuk Butter tree)
- How to Purify Water with Moringa Seeds
- How to Grow Moringa Trees
References and further reading
- Neem: A Tree for Solving Global Problems (BOSTID, 1992, 127 p.) http://www.cd3wd.com/CD3WD_40/CD3WD/AGRIC/B08NEE/EN/B1163_17.HTM
Books available at the Neem Foundation http://www.neemfoundation.org:
- Guidelines for Plantation (Marathi) Dr. H.M. Behl
- Kadu Nimb Anni Ayurveda (Marathi) Usha Rajendra Joshi
- Neem in Ayurveda (Hindi) Vaidya Suresh Chaturvedi
- Neem Kranti (Hindi) Radhekurnana Dubey
- Neem Yug (Hindi) R.A.S. Khangar
- The Neem Tree Prof. H. Schmutterer
- Proceedings Neem ‘99 Conf. Dr. H.M. Behl
- Neem: A User’s Guide K. Vijayalakshmi, K. Radha & S. Vandana
- Formulation of Neem – Based Products / Pesticides Dr. R.T. Gahukar
- Collection, Processing, Storage of Neem Seeds & Guidelines for Plantation Neem Foundation
- Neem in Ayurveda (English) Vaidya Suresh Chaturvedi
- Neem in Plant Protection Dr. R.T. Gahukar
- Proceedings of NEEM 2002, World Neem Conference, Mumbai – (Vol. 1 & 2) Neem Foundation
- Botanical Pesticides in Integrated Pest Management Dr. M.S. Chari /G. Ramprasad
- Neem: Application in Agriculture, Health Care & Environment Neem Foundation
- Development and Ecological Role of Neem in India Kamal Nayan Kabra
- Neem N.S. Parmar /N.S. Randhawa
- Monograph on Neem Dr. D. N. Tewari
- Neem: Azadirachta indica A. Juss Dr. R. P. Singh /Dr. R.C. Saxena
- Neem and Environment (Vol. 1 & 2) Dr. Singh
- Project Report on Plantation
- Neem: The Hidden Wealth – CD Films Division
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