Question:
Neem oil is used as organic pesticide. If it is true can anybody tell me what makes it so ?
2008-10-08 20:41:21 UTC
It was a question in my examination and I failed to answer it .
Three answers:
Harshal
2008-10-10 07:33:04 UTC
The Neem Tree (Azadirachta Indica) is a native of India.



Every part of the tree is useful, has medicinal, cosmetic and pest inhibiting properties.



Traditionally, the Neem tree's pesticidal and medicinal properties have been known and used for centuries in India.



The bark of the neem tree is used for cosmetics, health care products and medicinal preparations.



The leaves are medicinal The kernel of the neem fruit is crushed to yield an oil which is used chiefly in pest controlling preparations and also in medicinal, cosmetic and health care products.



The residue after crushing the kernel is neem cake, which is an excellent organic fertilizer.



Even the twigs of the tree are used as toothbrushes for dental hygiene. Small wonder that scientists have yet to come across a more beneficial tree!



Ingredients:



Neem is made up of about 40 different active compounds called Tetranortriperpernoids, or more specifically, liminoids.



Chemically these active ingredients or liminoids, are more akin to steroids.



When ingested by the insect, they create hormonal disruptions which prevent the insect from feeding, breeding or metamorphosing.



The main active ingredient of Neem is Azadirachtin.



It is a tetranortriterpenoid. It exhibits antifeedant, insect repellent and insect sterilization properties.



It is so potent that quantities as low as 1 ppm will totally repel certain insects.



It interferes with ecdysone, the key insect molting hormone and prevents larvae and pupae from completing the molting process.Insects treated with Azadirachtin during the larval and pupal stages, comprising 60-70 percent of their lives, generally die within 3 - 14 days.



Unlike chemical insecticides, it works on the insect's hormonal system, not on the digestive or nervous system, and does not lead to development of resistance in future generations.





TECHNICAL SPECIFICATIONS OF NEEM OIL :



1. Colour Dark : Greenish Brown

2. Odour Garlic, : Repulsive.

3. Moisture & Insoluble Impurities : 1 %

4. Refractive Index At 40 C : 1.4615 To 1.4705

5. Specific Gravity @ 30 C/ 30 C : 0.908 To 0.934

6. Titer : 35.8 C

7. Iodine Value : 65 -- 80

8. Saponification Value : 175 -- 205

9. Unsaponifiable Matter % By Wt. : 2 % By Mass, Max.

10. F.F.A. % By Weight : Upto 15 %



11. % Of



A. Myristic Acid : 2.6 %

B. Palmitic Acid : 13.6 To 14.9 %

C. Stearic Acid : 14.4 To 19.1 %

D. Oleic Acid : 49.1 To 61.9 %

E. Linoleic Acid : 7.5 To 15.8 %



12. % Of Glycerides



A. Fully Saturated Glycerides : 0.6 %

B. Tri-Unsaturated Glycerides : 22.0 %

C. Stearodiolein : 34.0 %

D. Palmitodiolein : 26.0 %

E. Oleopalmitostearin : 12.0 %

F. Oleodipalmein : 5.0 %



NEEM OIL Contains several - Terpenoids, Steroids, Alkaloids, Flavonoids,Glycosids, etc.. The isolated Constituents constituents are: Margosic Acid, Nimbin,Nimbidin, Nimbinin, Kaempeerol, Azadirone, Quercursertin, B - Sitosterol, Praisine,Vanilic Acid, Nimbicetin, Meliacins etc..







Pest control:



Some of the pests controlled by neem are Aphids, Army Worms, Beet Army Worms, Blow Flies, Brown Plant Hopper, Caterpillars, Chinch Bugs, Colorado Potato Beetle, Cotton Boil Worm, Cowpea Weevil, Desert Locust. There are many others Diamondback Moths, Fungus Gnats, Grain Borer, Green Rice Leaf Hopper, Greenhouse White Flies, Gypsy Moths, Horn Flies, Horn Worms, Japanese Beetles, Kharpa Beetle, Leaf Beetle, Leaf Hopper, Leaf Miners, Loopers, Mealy Bugs, Mexican Bean Beetle, Migratory Locust, Pink Boll Worm, Plant Bugs, Potato Tuber Moth, Red Cotton Bug, Red Flour Beetle, Rice Gal Midge, Rice Hispa, Rice Leaf Folder, Rice Weevil, Sorghum Shoot Fly, Spiny Boll Worm, Spotted Cucumber Beetle, Sweet Potato White Flies Thrips, Tobacco Caterpillar, Tobacco Horn Worm, Vegetable Leaf Miner, Web Worms, Weevils.
rajathicarolin
2008-10-09 12:40:54 UTC
Neem oil is generally light to dark brown, bitter and has a rather strong odour that is said to combine the odours of peanut and garlic. It comprises mainly triglycerides and large amounts of triterpenoid compounds, which are responsible for the bitter taste. It is hydrophobic in nature and in order to emulsify it in water for application purposes, it must be formulated with appropriate surfactants.



Neem oil also contains steroids (campesterol, beta-sitosterol, stigmasterol) and a plethora of triterpenoids of which Azadirachtin is the most well known and studied. The Azadirachtin content of neem oil varies from 300ppm to over 2500ppm depending on the extraction technology and quality of the neem seeds crushed.



Average composition of Neem Oil fatty acids

Common Name Acid Name Composition range

Omega-6 Linoleic acid 6-16%

Omega-9 Oleic acid 25-54%

Palmitic acid Hexadecanoic acid 16-33%

Stearic acid Octadecanoic acid 9-24%

Omega-3 Alpha-linolenic acid ?%

Palmitoleic acid 9-Hexadecenoic acid ?%
2008-10-09 03:48:44 UTC
Neem is rich in Azadirachtin. It is a chemical compound belonging to the limonoids. It is a secondary metabolite present in the Neem tree seeds. The molecular formula is C35H44O16. Azadirachtin is a highly oxidised tetranortriterpenoid which boasts a plethora of oxygen functionality, comprising an enol ether, acetal, hemiacetal, and tetra-substituted oxirane as well as a variety of carboxylic esters. It is classified among the plant secondary metabolites.

It is toxic to insects rather is agood reppelent. It in third generation pesticide.For Rest Read Unit of Modern Biology of Pradeep's objective Biology.


This content was originally posted on Y! Answers, a Q&A website that shut down in 2021.
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