Expert opinion

May 31, 2011

I have been told that that Neem tree leaves and seeds can be used to control pests. Is it true? How do they work?

I have been told that that Neem tree leaves and seeds can be used to control pests. Is it true? How do they work?

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.

These compounds belong to a general class of natural products called ‘limonoids’.
The liminoids present in neem make it a harmless and effective insecticides, pesticide, nematicide, fungicide etc.

The most significant liminoids found in neem with proven ability to block insect growth are: azadirachtin, salanin, meliantriol and nimbin. Azadirachtin is currently considered as neem’s main agent for controlling insects. ‘It appears to cause 90% of the effect on most pests. It does not kill insects – at least not immediately – instead it both repels and disrupts their growth and reproduction.

Research over the past years has shown that it is the most potent growth regulator and feeding deterrent ever assayed. It will repel or reduce the feeding of many species of pest insects as well as some nematodes. In fact, it is so potent that a mere trace of its presence prevents some insects from even touching plants.’
Online source

(adsbygoogle = window.adsbygoogle || []).push({});