Neem is a fast growing tree that usually reaches a height of 15-20 m, and under very favorable conditions up to approximately 30-35 m. As a rule it is a evergreen tree, but under extreme circumstances, such as extended dry periods, it may shed most of nearly all of its leaves. The branches spread widely. The fairly dense crown is roundish or oval and may reach a diameter 15-20 m in old free standing specimens. The trunk is relatively short, straight and may reach a girth of 1.5-3.5 m. The bark is hard fissured or scaly and whitish-gray to reddish-brown. The sap wood is grayish-white and the heart wood reddish.
Binomial name: Azadirachta indica
Nepali name: Neem
English name: Margosa or China berry or Paradise tree
Origin and Distribution:
- Native to India and upper Myanmar or Tropical South East Asia
- India, central and South America, Pakistan, Bangladesh, Srilanka, Mayanmar, Indonesia, Thailand, Sudan, Mauritius, Nigeria, Haiti, South-East Asia, Africa and tropical Australia
- Plant Description:
- A medium large evergreen , perennial tree , 15 to 25m in height,
- Stem – woody aerial, erect, spreading, branched, solid, straight clean trunk.
- The bark of the trunk is 1-2 cm thick , furrowed, longitudinally and obliquely, dark grey outside and reddish brown inside,
- The sapwood is yellowish white and heartwood is red or brown.
- The inner bark is reddish brown glabrous.
- Leaves- alternate, compound bipinnate and imparipinnate
- Inflorescence cymose, axillary panicle.
- Flowers- pedicellate, bisexual, small, pentamerous, white and fragrant purple flowers,
- Flowering usually February to may.
- Sepals – 5, Petals – 5, Stamens 10
- Fruit – One seeded drupe greenish yellow in colour endocarps woody,
- Ripen during June – August. Seed-ellipsoid, albumen thick fleshy 1- 1.5 cm long.
- Neem is a valuable, sacred, miraculous tree for its versatile use and has recently come to the focus of global attention.
- Deciduous in habit.
- It is native to India and the Indian subcontinent including Nepal, Pakistan, Bangladesh and Sri Lanka.
- Typically growing in tropical and semi-tropical regions.
- Neem trees now also grow in islands in the southern part of Iran.
- Its fruits and seeds are the source of neem oil.
- Climate and Soil
- Neem is a tropical, fast growing tree especially suited to semi – arid conditions.
- Grows in the plains in areas that reach an elevation of about 1500m -1800m.
- It can withstand temperature as high as 49˚c and low as 0˚C.
- Rainfall 130 – 200cm / yr.
- It can tolerate as little rainfall as 130mm /yr.
- Frost and hailstorm may affect its growth.
- It can be grown in subtropical and sub temperate climate also.
- The seeds are collected from June to August.
- The seeds remain viable for a short period of 3 to 5 weeks only.
- Ripe fruits, the pulp should be removed by hand (depulped) and seeds dried in the shade.
- Properly air dried seeds survive for at least 1 year in a refrigerator at 4˚C.
- Propagation through seeds,
- Sometimes Root cutting, Shoot cuttings or Root stumps are also planted.
- Preparation of Land:- 2-3 ploughings, 1-2 harrowing and levelling. Aldrex in the soil before planting are recommended.
- Nursery Bed:- Neem seeds are easy to germinate. Water soaking may be done for quick and better germination. Seed are sown in rows in 15 – 20cm apart at 1 to 1.5cm depth. The seedlings can be raised in basket and in polythene bags also. The beds are sparingly watered after sowing. Entire seedlings may be transplanted in the fields or planted inside thorny bushes to provide initial protection from cattle damages.
- Direct Planting: When seedlings become 8–16 weeks old ready for transplanting. In general 12 -18 months old seedlings are planted in the beginning of monsoon. Line sowing method is also practiced.
- Sowing season: May to July\August in nursery bed. Planting in the monsoon season (July to September) in the main field. Stem cutting of neem treated with 1,000ppm of IBA is best treatment which induces profuse rooting. Stem cutting treated with 100 ppm of IAA & NAA and GA3 is also produced roots affectively under mist chamber.
- Seed Rate: – About 5-8 kg / ha.
- Spacing: – Digging of pits, Size – 30 to 45 cm3.
- Manures and Fertilizers:- 20 – 25 tones of FYM / Compost / ha. 80:40:40 kg of NPK / ha. 5kg of organic manure/young tree. 10 -15 kg of org. manure/ adult tree.
- Interculture: 2-3 weeding and hoeing. Water logged condition is not suitable for Soil is put around the base to make small mound. Training and pruning is also needed at regular interval.
- Irrigation:- It needs irrigation frequently in the initial stages during summer months. 4-5 irrigations / year. Seedling stage is a critical stage where adequate soil moisture is needed.
- Intercrops: Cotton, Soybean, Groundnut, Millets, Sorghum, Seasamum, Garlic, Onion, Carrot etc
- Diseases:- Damping off (Fusarium oxysporum), Root rot (Ganoderma lucidun), Powdery mildew (Oiduim azadirchtae), Seedling blight (Fusarium solani), Leaf spots (Colletotrichum capsici), Bacterial leaf spot (Xanthomonas azadirachtae). Spray 0.01 – 0.2 % Dimethoate or Spray a mixture of 0.2% Dimethoate and Vipul @ 2ml /lit.
- Insect Pests: Leaf defoliators (Cleora cornaria and Odites utmopa), Sucking insects (Aspidiotus orientalis, Ceroplastes ceriferus. C. pseudo ceriferus), Shoot borer, Mollusca. The young neem plant should be protected against browsing animals.The mistletoes (Dendrophthoe falcate) are serious parasites of neem.
- Harvesting and Yield:
- The flowering starts in February –March and ends in May –June while shed their leaves during March April.
- Neem fruits are green drupes that golden yellow on ripening in the month of June to August
- The fruits can be collected from June till August.
- Leaves should be harvested just before flowering or after the seeds are set.
- The leaves of neem tree should be harvested when the plant 2-3 years old or 6-8m tall tree.
- Hand plucking is usually done.
- Neem starts bearing fruits at the age of 5 years.
- 15 – 20 years old tree for timber purposes.
- Yield: – 350 – 400kg of dry leaves / yr. and 60 – 100kg fruits / yr. obtained from 8 m. tall tree. It produces about 50 -60 kg berries /tree and the kernel yields 45% of fixed oil.
- Chemical Evaluation:
- The principal constituent is ‘Limonoids’ which is active ingredient, isolated from leaves, flowers, seeds and bark of neem tree.
- ‘Azadirachtin’, Nimbin, Salanin, Nimbolin Beta, Meliantriol Deacetylaza, Quercerin, Myrcetin, Nimbosterin, Nimocetin are most important limonoids.
- Leaves:- It contain Ca, Mg, Fe, P, crude fibers, carbohydrates, fats, proteins, vitamins, and alkaloids. Mainly yield quercetin (flavanoid), nimbosterol, nomicinol. It also contain glutamic acid, tyrosine, aspartic acid, alanine, glutamine, cystine.
- Dry Flowers: – Mainly yield Nimbosterol, Kaempferol, Nimocin, Myricetin, Quercetin..
- Trunk Barks: It contains Nimbin, Nimbinin, Nimbidin, Nimbosterol, Tannins, Margosine, Margosic acid, Essential oils, Nimbicidin. Bark contains about 14% tannin. Neem Seeds: It contains Ca, Mg, P, Azadirachtin, Epinimbin, Margosopicrin, Salanin, Meliantriol, Meliacin and Vilasimin.
- Neem oil: Desacetyl nimbin. It contains various fatty acids and sulphur containing products.Neem oil is colourless or white liquid in pure form, or greenish yellow to brown colour, non-drying, bitter in taste and possess a stong characteristic garlic like odour.
- Key Action: Antifeedant, Antimicrobial, Anthelmintic, Astringent, Antiulcer, Antiseptic, Diuretic, Vermifuge, Dermatis, Insect- repellent.
- Medicinal Uses:
- Leaves: Anthelmintic ; (expel parasitic worms), Insecticidal.;Used in Skin diseases; Scborrhoeie Dermatitis (long-term skin disorder), effective against aflatoxin; (toxin produced by fungi), Feeding green leaves can also help in boosting milk secretion after parturition. Leaves are also useful as mulch manure. Carminative; (prevent the formation of gas in gastrointestinal tract), Expectorant; (promotes secretion of sputum, treat caugh).
- Flowers: Neem flowers are useful for dyspepsia (indigestion), general debility (physical weakness due to illness).
- Bark:- The bark yields tannin and gum. The amber–hued gum is used as a dye in textile and tradition medicine. The bark is useful for leprosy, blood complaints, diuretic, cardio – vascular diseases, ulcers and inflammations. A bitter tonic is prepared from neem bark. Shampoos, Soaps, Hair tonics, Tooth pastes, Gargles have been prepared with Nimbidin and with the salts of the acid derived from it. It is used in the treatment of leprosy and tuberculosis. It is useful as a refrigerant lubricant.
- Neem oil:- It is used for making soaps (Trade name – Neem, Morgosa) cosmetics, tooth paste. Oil is also used as lubricants. It is used to antiseptic, anti bacterial, antifertility, antihelmintic and cosmetic preparations.
- Neem timber:- The timber is very durable and is useful for house building furniture, bullock carts, wooden plough and other agriculture implements.
- Use of Neem in Agriculture:- Neem contains several active chemicals in various plant parts. Several plants products are used for the control of plant diseases, insect pests and grain stored pests.
- Neem Seed Kernel Extract:-
- It is prepared by soaking 5kg of powdered neem seed kernel in 100 lit of water for 8 hrs.
- Then vigorously stirring.
- The extract should be mixed with 100ml teepol (adhesive).
- 500 lit of the extract is required for 1 hectare.
- Diseases and insect pests controlled by using Neem products. Tungro virus, Sheath blight, Mosaic virus, Leaf hopper, nematodes.
- Neem Oil Solution:-
- It is prepared by mixing 3 lit of neem oil to 100 lit of water with 100 ml of teepol.
- The milky solution formed is used for spraying the following diseases. – Blast, Rust, Foot rot, Powdery mildew, Yellow mosaic virus, Aphids
- Neem Cake:-
- It contains oil, N, Mg, Ca, S, ash, carbohydrates and fibers.
- Powdered neem cake is directly applied to the field at the time of last ploughing.
- Apply 150kg of neem cake / ha. Diseases are- Sheath blight, Wilt, Root rot, Tuber rot disease, Root rot of cotton Stem borers, white ants.
- Neem Cake Extract:-
- Ten kg of powdered neem cake is taken in a muslin cloth bag and soaked in 100 lit of water for 8 hrs.
- Then the bag is removed after thorough shaking.
- The extract is mixed with 100 ml of teepol.
- For spraying 1 ha. 500 lit of extract is required.
- Neem Powder:-
- For Store – grain pests.
- Commercial (Trade) Products of Neem. (Used in Agriculture only) Azadil, Amitul, Bioneem, Econeem, Methrin Ninaba, Nimbosol, Nimlin, Neemax, Neem oil Emulsion, Neem Top, Neemhit, Neemba – 2100Margos
- Other Uses
- Traditionally neem is used against a wide variety of diseases which include heat-rash, boils, wounds, jaundice, leprosy, skin disorders, stomach ulcers, chicken pox, etc.
- The timber of neem tree is very durable and is used for house building and carpentry work.
- Dried leaves are placed among clothes to keep moths away.
- It is usually rubbed directly on the infected skin
- Neem seeds are useful in treating tuberculosis.
- It kills germs and cleanses the atmosphere.
- The neem leaves can help to reduce swelling and purify blood.
- Neem should not be: taken by anyone who is pregnant or trying to conceive. Never be used to treat children with fevers. Neem oil should not be taken internally.