I recently read this report  and they said....

Comparing four synthetic compounds to a pair of natural pesticides, Hallett and her colleagues discovered that the natural products were generally less effective at getting rid of the aphids. Thus, they needed to apply more of them to get the same result as the traditional pesticide.

"Ultimately, the organic products were much less effective than the novel and conventional pesticides at killing the aphids and they have a potentially higher environmental impact," Hallett said.

Read more: http://www.cbc.ca/consumer/story/2010/06/23/guelph-pesticide-study.html#ixzz1CY4Q8hcO

1.They dont mention what Natual Pesticides they were using

2.  They dont seem to understand the way natural pesticides work.. You cannot grow chemically and then expect natural pesticides to work if at all.

3. To say that natural pestcicides pollute the enviroment just as chemical ones due is total BS

andy