The way of nature to balance itself
General Description:
Neem botanically known as Azadirachta indica belonging to the family Meliaceace is native to Indian sub-continent and to the parts of South-east Asia. The tree is evergreen and noted for its wide adaptability and thrives in Sub-humid to semi-arid and arid climatic conditions. It can grow in different types of soil and with wide range of pH. Nevertheless, poorly drained soils and waterlogging are not suitable. Neem has ability to improve soil fertility and water holding capacity through its unusual property of calcium mining, thereby neutralizing the pH.
People have known about the multiple uses of Neem since ancient times. They used tender shoots, flowers, and leaves to prepare vegetables. They also prepared medicines using extracts from Neem. People use the wood from Neem as timber. Additionally, they use twigs and barks of Neem as oral deodorant, toothache reliever, and for cleaning teeth. Furthermore, people use Neem oil as a remedy against ticks, mites, and lice on the bodies of domesticated animals. Neem cake was occasionally provided as feed to the cattle as a source of protein and as organic fertilizer. Due to the insecticidal nature, neem was used as pesticide/insecticide in various ways.
However, after studies and research on Neem revealed its toxic effects on humans and animals in higher amounts or doses, the dosage and quantity of neem to be used were then limited or controlled.
Due to all these properties and characteristics, Neem is also called as “Wonder Tree”.
Neem as a pesticide:
Neem has derived its pesticidal property from a general class of phytochemicals it contains called “liminoids”. These includes azadirachtin, nimbin, meliantriol & Salannin. Major effects are being produced against aphids, and the extract from neem is known to act on insects/pests in the following ways:
- Sterilizing adults
- Blocking the ability of insects to “swallow” or suck the cell sap.
- Disrupting or inhibiting the development of eggs, larvae or pupae.
- Blocking the moulting of larvae or nymphs
- Disrupting mating and sexual communication
- Repelling larvae and adults
- Disturbing the females from laying eggs
The following are the ways in which Neem is used as pesticide:
Neem Oil:
Neem oil is extracted from neem seed. The oil smells very pungent. It can be either prepared manually by crushing/grinding the seeds or can be brought ready-made preparation from market. The oil is sprayed to the surface of plant especially to the pest infested area. The recommended dosage is
Neem Cake:
The Neem cake is the mixture of byproduct formed from the residues left after extraction of Neem oil, decomposing neem leaves and crushed neem bark. It is applied directly to the soil. It acts as an insecticide/Nematicide and kills soil borne insects/nematodes. An added advantage of this cake is that it also act as fertilizer; it reduces the loss of nitrogen in soil as it reduces the volatization. It is recommended to apply.
Neem Leaves:
The leaves of neem is used majorly during storage of produce. The leaves are spread in alternate layers while storing cereals/pulses in old earthen/bamboo structures. This method protects from the attack of storage pests and helps in increasing the shelf life. People uses neem leaves during the preparation of any Herbal spray like Jeevamrut/10-leaf extract.
Additional points:
- As the chemical compounds of Neem extracts are instable to direct sunlight/pH, applications must be done in early morning or in evening when there is shade.
- Research institute BARC has invented a product which solves the above mentioned problem.
- Over-dosage must be overseen as it can burn the plant parts
References:
- barc.gov.in
- http://www.agritech.tnau.ac.in/
- www.fao.org
- Personal and other references