In Colombia, ground crews a bigger part of the cocaine battle

Guarded by a cordon of 120 anti-narcotics police officers, the group uses metal rods to uproot bush after bush on the steep hillside. In a gully below stands a thatched-roof laboratory where farmers processed a kilogram of coca paste a week, worth about $1,000 each, before fleeing last month, police said.

Lopez leads Mobile Eradication Group 5, one of scores of 30-man teams of laborers the government has deployed across the nation to manually destroy coca crops, a program now deemed nearly as important to the drug fight as sprayed weedkiller.

On a recent day, Lopez and his comrades were on the outskirts of this river town in Antioquia state. They marched into the hills that are polka-dotted with distinctive lime green patches of the shrub whose leaves are cocaine's raw material.

"We just keep going until it's gone," said Lopez, 32, a wiry onetime narco-trafficker who gave up coca farming after tragedy struck. "I feel proud of what we do because I know from experience these bushes are the root of all that's evil in Colombia."

Spraying from crop-dusters is still the preferred eradication weapon of Plan Colombia, the U.S.-funded initiative targeting illegal drugs and terrorism. But disappointing results from years of aerial spraying, plus fears of environmental damage caused by the chemicals used, have led U.S. and Colombian officials to put more emphasis on teams like Lopez's.

This year, ground crews will destroy 250,000 acres of coca, 67% more than in 2007, compared with the 325,000 acres of coca to be sprayed this year, Colombian and U.S. officials said. Five years ago, manual eradication represented less than one-tenth of all coca crops destroyed, the officials said.

The shift is having an effect, the White House Office of National Drug Control Policy says. In a visit to Colombia last month, the office's director, John P. Walters, said street prices of cocaine in the States were up 6% in the 12-month period that ended June 30 and up 25% since January 2007.

Higher prices indicate that efforts to control the supply and trafficking of cocaine are working, Walters said.

"There has been a market meltdown in the cocaine business," Walters said in an e-mail to The Times. "We have made huge strides in breaking the machine that delivers addiction, violence and misery to our nations."