No person shall--
(a) cultivate any coca plant or gather any portion of coca plant; or
(b) cultivate the opium poppy or any cannabis plant; or
(c) produce, manufacture, possess, sell, purchase, transport, warehouse, use, consume, import inter-State, export inter-State, import into India, export from India or tranship any narcotic drug or psychotropic substance, except for medical or scientific purposes and in the manner and to the extent provided by the provisions of this Act or the rules or orders made thereunder and in a case where any such provision, imposes any requirement by way of licence, permit or authorisation also in accordance with the terms and conditions of such licence, permit or authorisation:
Provided that, and subject to the other provisions of this Act and the rules made thereunder, the prohibition against the cultivation of the cannabis plant for the production of ganja or the production, possession, use, consumption, purchase, sale, transport, warehousing, import inter-State and export inter-State of ganja for any purpose other than medical and scientific purpose shall take effect only from the date which the Central Government may, by notification in the Official Gazette, specify in this behalf:
[Provided further that nothing in this section shall apply to the export of poppy straw for decorative purposes.]