wrote in message
...
On Jan 14, 6:01 pm, K wrote:


Chemical fertilisers were introduced before the 50s.

So yes, I might be wrong - but in all respect there
was no use of chemicals before this.



Yes you a
http://pubs.caes.uga.edu/caespubs/pubcd/B1121.htm
Historical Developments with Pesticides
Pesticides are not new. Ancient Romans killed insect pests by burning sulfur
and controlled weeds with salt. In the 1600s, ants were con-trolled with
mixtures of honey and arsenic. By the late nineteenth century, U.S. farmers
were using copper acetoarsenite (Paris green), calcium arsenate, nicotine
sulfate and sulfur to control insect pests in field crops, but results were
often unsatisfactory because of the primitive chemistry and application
methods



pk