Propagation of Neem and Harvest of Seeds

Neem tree can grow under various condition of climate and soil types. The ripe seeds should be grown soon after collection. It can be sown directly or it can also be transplanted. Neem can also be propagated in a variety of other ways. This chapter briefly describes the propagation techniques of neem. besides instead of collecting seeds that fall on the ground.

Propagation Techniques of Neem
The tree can be easily propagated both sexually and vegetatively. It can be planted using seeds, seedlings, saplings, root, suckers, or through tissue culture. However, it is normally grown from seed. neem seeds are not viable for a very long time. After about two weeks they will no longer germinate. The seeds that are removed from the fruit should be put in water. Those seeds which sink are good ones and should be used. Some studies have shown that they can be used even after many years but only under specific condition and germination capacity is under 50%. Neem cuttings have to be planted as soon as they are cut for the neem to survive. The part that is cut is covered with straw and should be kept wet if it is to be planted after some time.

Preparation of nursery and Sowing
The soil should be dug 30 cm deep. Raised beds of 10m length, 1 m breadth and 15 cm height should be prepared. Farmyard manure, sand and local soil should be mixed in the ratio 1:1:3. This should be put on top of the soil for a height of 2.5 to 5 cm. Seeds are normally sown in the nursery in the months of July and August. The seeds should be sown at a distance of 15 to 20 cm and a depth of 1 to 1.5 cm, and then watered. There is no dormant period for neem seeds. Hence they can be sown as soon as they are collected. They germinate in a week’s time.
 

After 5 to 6 weeks the seedlings are removed from the nursery and planted in second nursery or in polythene bags. if polythene bags are used for transplanting, the bag should be filled with silt, sand,clay and farmyard manure in the ratio of 1:1:1:1. The seeds can also be sown directly in the polythene bags at the rate of 2 per bag. The healthy seedling is maintained and the other one removed. if the seeding are raised in the polythene bag they can be transported for long distances when required and then transplanted. The polythene bags that are used should be 150-200 gauge in weight. In the nursery a thatch should be provided for seedlings.

Transplantation
The place where neem seedlings are to be transplanted should be properly ploughed, The seedlings are ready for transplantation when they are six months old (15 to 22.5 cm height). If the seedlings which are kept for a long period the tap roots become very long and it is difficult to take out without breaking of roots. Seedlings which are healthy and not afflicted with any diseases should be chosen. Pits of dimension 30*30*30 cm should be dug at intervals of 3*3 m. The neem seedling should be transplanted during the period of the South East Monsoon. This increase their survival rate. Initially, they should be watered once in two or three day. After they grow well they can be wanted once in seven to ten days.

Harvesting of Neem Seeds
In most parts of India today, seeds that fall on the ground are simply collected. Neem fruit fall coincides with the monsoon. A known health hazard may arise because of poor handling. At moisture content above 14%, neem fruits carry the fungus Aspergillus flavus. This fungus under many conditions produce aflatoxins. Aflatoxins are extremely potent among carcinogens known and these could also contaminate seeds inside the fruits. They are extracted and concentrated along with pesticidal ingredients. This could prove to be a great barrier to the wide use of pesticides from this most promising tree.
From the human health point of view neem oil which is contaminated with aflatoxins can be of great significance in that it cannot have the same type of pesticidal property. Seed viability is also lowered. To avoid all this actual harvesting of seeds is recommended rather than a simple collection of seeds.
 

While harvesting neem seeds it must be ensured that the fruit colour is neither greenish yellow nor brownish yellow but plain absolute yellow. Greenish yellow fruit are not fully mature and are low in Azadirachtin content. After indentifying trees which have yellow fruit a tarpaulin cloth or plastic paper is spread under the tree. A stick is used to beat the branches the same way as one would to collect Tamarind.
 

Neem fruits now drop on the tarpaulin or plastic sheet. Since they do not come in contract with soil, there is no fear of fungus attack and aflatoxin development. Seeds thus collected are brought to the shade where one can further work on them. By twisting yellow fruits between index finger and thumb the pulp is removed. After the removal of pulp the seeds should be milky white in colour. The seeds are dried in shade for two or three days. The seeds are turned upside down while they are put to dry.
 

This type of harvesting increase the germinating capacity and viability of the seeds. The seeds also have better bio-efficacy and can be sold at absolute premium price in the markets.