Afghanistan has been the greatest illicit opium producer in the entire world, ahead of Burma (Myanmar), the "Golden Triangle", and Latin America since 1992, excluding the year 2001.
Source: "UNODC 2010 world drug report, page 43" (PDF). Retrieved November 30, 2011.
During the Taliban rule, Afghanistan saw a bumper opium crop of 4,500 metric tons in 1999,. However, in July 2000, Taliban leader Mullah Mohammed Omar, collaborating with the United Nations to eradicate heroin production in Afghanistan, declared that growing poppies was un-Islamic, resulting in one of the world's most successful anti-drug campaigns. As a result of this ban, opium poppy cultivation was reduced by 91% from the previous year's estimate of 82,172 hectares. The ban was so effective that Helmand Province, which had accounted for more than half of this area, recorded no poppy cultivation during the 2001 season.
Sources: "Press conference on afghanistan opium survey 2004" (Press release). United Nations. November 18, 2004. Retrieved January 14, 2006. United Nations International Drug Control Programme (UNDCP) (PDF). Annual Opium Poppy Survey 2001. Retrieved January 20, 2008. Taliban's Ban On Poppy A Success, U.S. Aides Say, By BARBARA CROSSETTE nytimes.com, Published: May 20, 2001