The value of opium produced in Afghanistan increased by 133 percent last year to $1.4 billion, or about 9 percent of the country’s GDP, according to a new Afghanistan Opium Survey [PDF] released by the United Nations Office on Drugs and Crime (UNODC).

UNODC estimates the 2011 export value of Afghanistan’s opium to be $2.4 billion — or 15 percent of GDP. “These amounts cannot easily be substituted by other economic activities,” according to the report, which noted farmers can make 11 times more growing opium than wheat — the largest disparity since 2003.

Sixty percent of the opium farmers surveyed reported that they were motivated by the high prices the crop fetches.

As we reported two weeks ago in Opium Brides, Afghanistan produces 90 percent of the world’s opium, fueling the global heroin trade and funding both the Taliban and government-linked warlords and bringing billions of dollars a year into the country’s economy.

But, as Opium Brides shows, the Afghan government’s efforts to eradicate poppy crops across the country has had a horrifying, unintended consequence, as young Afghan girls are kidnapped or traded to smugglers to meet the debts of impoverished opium farmers. In this clip, a number of Afghan farm families discuss the deadly bargains they’ve been forced to make with the smugglers.

You can watch the full film here, or read more about why eradication won’t solve Afghanistan’s poppy problem.