Satish Lele satish.lele@gmail.com

Neem trees are normally planted everywhere in India, for purification of air. Billions of trees exist all over India. If the seeds fallen on ground are collected, and oil is extracted at village level expellers, thousands of tons of oil will be available for Lighting the Lamps in rural area. Neem is the best oil for lighting. Since these are spread over a large area, collection of seeds for BioDiesel manufacture is not viable. (A compact plantation can support a BioDiesel plant).
Climate: The Neem has adapted to a wide range of climates. Neem thrives well in hot weather, where the maximum shade temperature is as high as 49^oC and tolerates cold up to 0^oC on altitudes up to 1500 meters. Today, Neem is well established plant in at least 30 countries world-wide, in Asia, Africa and Central and South America. Some small scale plantations are also reportedly successful in the United States of America.

Soil: The Neem grows on almost all types of soils including clay, saline and alkaline soils, with pH up to 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, Neem 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 Neem has a unique property of calcium mining, which changes the acidic soils into neutral.
Requirement of Water: 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, Neem has been introduced successfully even in areas where the rainfall is as low as 200 to 250 mm. Neem cannot withstand water-logged areas and poorly drained soils.
Time to Mature: 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 to 50 kg. of fruit every year.
Life of Tree: It is estimated that a Neem tree has a productive life span of 150 to 200 years.
Organic Farming: The Neem Tree (Azadirachta indica A. juss) and its derivatives have great relevance in organic farming practices. The tree is a renewable resource for home grown agro-chemicals and nutrients which are bio-degradable, non-toxic and effective.
Pest Control: Neem seeds and leaves contain many compounds which are useful for pest control. Unlike chemical insecticides, neem compounds work on the insect's hormonal system, not on the digestive or nervous system and therefore does not lead to development of resistance in future generations. Neem has had a long history of use primarily against household and storage pests and to some extent against crop pests in the Indian sub-continent.
Crop Pests: M. N. Nagendra Prasad, Lecturer in Biotechnology, S. J. College of Engineering, Mysore, has been working on a destructive disease of neem for last 8 years. The disease is called die-back caused by a pathogen called Phomopsis azadirachtae, a deuteromycetes fungi. He has published quite a number of papers on the severity and the incidence of fungi in different parts of India. The disease is so destructive that fungi can kill the tree completely over a period of time and further incidence is as high as 90% in karnataka and Tamilnadu, if you need any other details on Neem contact him at npbiotech@yahoo.com
Fertilizer: Indian farmers have traditionally used deoiled Neem cake as a fertilizer in their fields. The dual activity of Neem cake as fertilizer and pest repellent, has made Neem cake a favoured input. Neem leaves have also been used to enrich the soil. Together, they are widely used in India to fertilize cash crops. When Neem cake is ploughed into the soil Neem cake also protects plant roots from nematodes and white ants. Farmers in southern parts of India puddle neem leaves into flooded rice fields before the rice seedlings are transplanted.

Neem for Sustainable Agriculture and Environmental Conservation: In the past two decades, "Green Revolution Technologies" have more than doubled the yield potential of rice and wheat, especially in Asia. These high input production systems requiring massive quantities of fertilizers, pesticides, irrigation, and machines. However, disregarding the ecological integrity of land, forests, and water resources, endanger the flora and fauna, and cannot be sustained over generations. Also, we cannot look to the sea in future as fishing stocks in many parts of the world are already in crisis due to over fishing or pollution. To a great extent, future food security and economic independence of developing countries would depend on improving the productivity of biophysical resources through the application of sustainable production methods, by improving tolerance of crops to adverse environmental conditions, and by reducing crop and post-harvest losses caused by pests and diseases.
Environmentally Friendly Agricultural Technologies: Appropriate technologies, which do not assault the nature, would have key roles to play in ensuring food security, in improving human health, and in rehabilitating and conserving the environment to safeguard the well being of the posterity. Instead of striving for more "Green Revolutions" with emphasis on miracle seeds, hard hitting, synthetic and engineered pesticides, and increased use of fertilizers, the future must look to natural ways and processes for augmenting agricultural productivity. In fact, all development efforts and activities should be within well defined ecological rules rather than within narrow economic gains. Sustainable agricultural systems must be ecologically sound for long-term food sufficiency, equitable in providing social justice, and ethical in respecting both future generations and other species. For developing countries, the use of the neem tree may provide a key component in more sustainable agricultural system including pest and nutrient management, human health, and environmental conservation.
Neem and Environment: Neem has powerful pest controlling activities and medicinal properties. More importantly, pesticides made from neem are much safer compared to synthetic pesticides. The side-effects of the synthetic pesticides are often not less serious than the problems themselves. They cause environmental contamination and are a great risk to human health. As a consequence, there has been an intense search for safer pesticides.
Environmental Service by Neem: Neem in Indian culture has been ranked higher than 'Kalpavriksha', the mythological wish-fulfilling tree. In 'Sharh-e-Mufridat Al-Qanoon', neem has been named as 'Shajar-e-Mubarak', 'the blessed tree', because of its highly beneficial properties. Although scientific studies are wanting, neem is reputed to purify air and the environment of noxious elements. Its shade not only cools but prevents the occurrence of many diseases.
During hot summer months in northern parts of the Indian subcontinent, the temperature under the neem tree is ~10^oC less than the surrounding temperature. Ten air conditioners operated together may not do the job as efficiently and economically as a full grown neem. Restoration of the health of degraded soils and ultimate use of such reclaimed waste lands through neem is another example of its value as an environmental panacea.
Neem in Reforestation and Agro-Forestry: Neem is a very valuable forestry species in India and Africa and is also becoming popular in Tropical America, the middle-east countries and in Australia. Being a hardy, multipurpose tree, Neem is ideal for reforestation programs and for rehabilitating degraded, semiarid and arid lands.
Biomass Production and Utilization: Full grown neem trees yield 10 to 100 tons of dried biomass per hectare, depending on rainfall, site characteristics, spacing, ecotype or genotype. Leaves comprise about 50% of the biomass, fruits and wood constitute one-quarter each. Improved management of neem stands can yield harvests of about 12.5 cubic meter (40 tons) of high quality solid wood per hectare.
Neem wood is hard and relatively heavy and used for religious icons in some parts of India. The wood seasons well, except for end splitting. Being durable and termite resistant, neem wood is used in making fence posts, poles for house construction, furniture etc.
Economic Potential of Neem: According to some estimates, there are about 20 million neem trees in India. A neem tree normally starts fruiting after 3-5 years. In about 10 years Neem becomes fully productive. Under favourable conditions fresh fruit yield per fully grown tree is about 50 kg per year. There is a potential of about 540,000 tons of seed, which can yield about 107,000 tons of oil and 425,000 tons of cake. However, in spite of good demand, only about 25 to 30 percent of the neem seed is collected in India, indicating a large untapped potential.
The recovery of oil from poor quality seeds is not good. That is why the price paid for such seeds is low. Collection and drying of seeds are the main problems at the village level. The seed needs to be de-pulped immediately after collection, sun dried and stored till crushed for oil extraction. Any delay in de-pulping the seed and drying affects the quality in respect of oil content. Properly dried seeds can be stored up to one year, although Neem seed has been recommended to store for a minimum of three months after collection for maximum oil recovery.
Appropriate Method for Storing Neem Seeds: As the dried sees can also become mouldy during storage, they should only be stored in airy containers (e.g. jute sacks or baskets). Airtight containers such as plastic bags or pots are unsuitable.
Other Uses of Neem Oil: Apart from pesticide application for storage and protection, neem oil has been a trusted remedy for a naturally healthy skin in the villages of India. Derived from the seeds of the neem tree, Neem oil contains all the disinfecting and healing properties of the tree, in a concentrated easily usable form. For centuries, this therapeutic oil has provided protection and oil is used for soap making, pharmaceuticals such as creams. Neem oil is currently used in cosmetics for creams, lotions and shampoos.