KABUL, Afghanistan – Springtime is on the way and already hundreds of farmers are tending pale green shoots of Afghanistan’s chief crop and economic mainstay: opium poppies.

It looks to be a bumper year. Some 320,000 acres are currently blanketed in rows of dandelion-like sprouts that eventually produce almost 90% of the world’s heroin.

But drug agents are counterattacking. An army of 500 tractor-driving Afghans hopes to plow the plants under before producers grow powerful enough to corrupt the country’s fledgling government.

“There’s going to be a continuous effort in spring and summer,” U.S. Army Lieutenant General Karl Eikenberry, the top American commander in Afghanistan, said in an interview Tuesday with the Associated Press.

When the Taliban ran Afghanistan, its leader enforced an effective ban on poppy growing under threat of jail. As a result, cultivation dropped to practically nothing in 2000.

But Afghan and Western counter narcotics officials say the hardline Taliban militia fighting the American-backed government is now implicated in the trade and uses the proceeds to help fund its insurgency.

The dramatic increase in poppy cultivation since American forces ousted the Taliban from power in late 2001 has caused alarm in the West, particularly Europe, the destination of most of the drugs. Only a fraction of the output is consumed inside Afghanistan.

Getting farmers to stop growing the flowers – which thrive in Afghanistan’s poor soil and abundant sunshine – will take decades, General Eikenberry said. Thailand’s largely successful campaign took 25 years. Afghanistan’s crop is being eradicated amid a guerrilla war and some of the world’s starkest poverty. It will take longer, General Eikenberry said.

One farmer in Kandahar’s poppy belt, Haji Abdul Karim, says planting his 12 acres with poppies is the only way to feed his six sons and two daughters. Revenue from wheat or grapes wouldn’t even cover cooking fuel, Abdul Karim said.

“I have no other option,” the 40-year-old farmer said. “I don’t like growing poppy. If I had another way to earn money, I wouldn’t grow it.”

The U.S. Agency for International Development has earmarked $146 million this year for economic development and export-oriented farming projects meant to wean Afghans from the crop. American funds are paying for replanting poppy fields with orchards of apricot, apple, pomegranate and nut trees and grape vines.

Even so, a U.N. survey released Monday said this year’s crop would be larger than last year’s – though smaller than the record 2004 crop of about 500,000 acres.

One reason cultivation has risen is that threats to cut down last year’s crop never materialized, an American drug agent said, speaking on condition of anonymity because of his involvement in sensitive counternarcotics operations. This year, agents hope threats are now backed by action.

Making matters more difficult, farmers like Mr. Abdul Karim may receive protection from drug gangs who have warned of attacks on government eradication teams. Last year, several team members were killed in action.

And drug gangs are finding unlikely allies among radical Muslim insurgents, especially in southern Afghanistan, according to General Eikenberry.

“We’ve seen some evidence of cooperation with the Taliban,” he said.

The heroin industry has become so strong that the corruption and crime it fosters are endangering the government, General Eikenberry said.

“You’ve already got a narco-economy here. We don’t want it to become a narco-state,” said the drug agent, who estimated that opium and heroin smuggling accounts for more than 35% of Afghanistan’s economy.

American and British narcotics agents hope to eradicate 50,000 acres of this year’s crop before sap is collected and smugglers trundle heroin to markets across Asia and Europe.