WASHINGTON (AP) -- U.S. and UN experts agree that Afghanistan will harvest fewer poppy plants bound for the drug trade in 2008 after two years of record crops. They have radically different estimates, however, about what the decline will mean for opium production.

In a report obtained by The Associated Press before its planned release Friday, the Bush administration contends that production of the heroin precursor will plunge by 31 percent, from 8,000 metric tons in 2007 to 5,500 metric tons this year. That is more than five times the drop in production predicted by the United Nations in late August.
The White House Office of National Drug Control Policy maintains its estimate is accurate. Its director, John Walters, said the UN report may contain ""methodological anomalies"" related to on-the-ground surveys of poppy fields and stocks and not factor poor weather into its production estimate.
The Vienna-based UN Office on Drugs and Crime, which compiled the UN report, was not immediately available for comment, but an official at its New York branch defended its estimate, calling the discrepancy ""surprising"" and ""not logical."" The official spoke on condition of anonymity because he was not authorized to speak out on the matter.
When the UN report was released on Aug. 26, officials said that despite a 19 percent drop in cultivation, opium production would go down only 6 percent because of a rise in yield.
The U.S. report estimates that poppy cultivation is down a similar amount, 22 percent, but says yields also have fallen. Walters's office noted that the United States and the United Nations use different data collection and analysis techniques to compile their estimates.
Walters said the U.S. estimate included factors affecting opium production, such as drought, that the United Nations might not have used. Both reports, however, did factor the weather into cultivation.
UN experts said the drought was a crucial reason, along with anti-drug campaigns, for the significant decline in poppy cultivation from 477,000 acres, or 193,000 hectares, in 2007 to 388,000 acres in 2008. The U.S. report estimates that cultivation fell from 499,000 acres in 2007 to 388,000 acres in 2008.
Regardless of the difference in opinion over what the drop will mean for opium production, Walters said the decline in cultivation, particularly that 18 of Afghanistan's 34 provinces which are now poppy free, up from 15 in 2007 and 12 in 2006, is ""good news"" and a sign that counternarcotics efforts are working after years of failure.
""It gives us a clear indication that we can do this, we just need to sustain it,"" he said, noting that anti-drug campaigns were working especially well in Afghanistan's north and east where incentive programs aimed at rewarding local officials for declines in poppy cultivation have been most successful.
The Bush administration has spent $2.8 billion to fight drugs in Afghanistan since 2002, but until this year it had seen poppy cultivation on the rise and record harvests in both 2006 and 2007.