LAZARO CARDENAS, Mexico — Soldiers trying to seize control of one Mexico's top drug-producing regions found the countryside teeming with a new hybrid marijuana plant that can be cultivated year-round and cannot be killed with herbicides.
Soldiers fanned out across some of the new fields Tuesday, pulling up plants by the root and burning them, as helicopter gunships clattered overhead to give them cover from a raging drug war in the western state of Michoacan. The plants' roots survive if they are doused with herbicide, said army Gen. Manuel Garcia.
"These plants have been genetically improved," he told a handful of journalists allowed to accompany soldiers on a daylong raid of some 70 marijuana fields. "Before we could cut the plant and destroy it, but this plant will come back to life unless it's taken out by the roots."
The new plants, known as "Colombians," mature in about two months and can be planted at any time of year, meaning authorities will no longer be able to time raids to coincide with twice-yearly harvests.
The hybrid first appeared in Mexico two years ago but has become the plant of choice for drug traffickers Michoacan, a remote mountainous region that lends to itself to drug production.
Yields are so high that traffickers can now produce as much marijuana on a plot the size of a football field as they used to harvest in 10 to 12 acres. That makes for smaller, harder-to-detect fields, though some discovered Tuesday had sophisticated irrigation systems with sprinklers, pumps and thousands of yards of tubing.
"For each 100 (marijuana plots) that you spot from the air, there are 300 to 500 more that you discover once you get on the ground," Garcia said.
The raids were part of President Felipe Calderon's new offensive to restore order in his home state of Michoacan and fight drug violence that has claimed more than 2,000 lives in Mexico this year.
In Michoacan, officials say the Valencia and Gulf cartels have been battling over lucrative marijuana plantations and smuggling routes for cocaine and methamphetamine to the United States. In one incident, gunmen stormed into a bar and dumped five human heads on the dance floor.
The president, who took office Dec. 1, sent 7,000 soldiers and federal officers to Michoacan last week.
Officials have arrested 45 people, including several suspected leaders of the feuding cartels. They also seized three yachts, 2.2 pounds of gold, bulletproof vests, military equipment and shirts with federal and municipal police logos. More than 18,000 people have been searched, along with 8,000 vehicles and numerous foreign and national boats.
"We are determined to shut down delinquency and stop crime in Mexico because it is endangering the lives of all Mexicans, of our families," Calderon said, calling the operation a "success" so far.
In the past week, soldiers and federal police have found 1,795 marijuana fields covering 585 acres in Michoacan, security officials said.
Officials estimate the raids could cost the cartels up to $626 million, counting the value of plants that have been destroyed and drugs that could have been produced with seized opium poppies and marijuana seeds.
On Sunday, federal authorities announced the capture of suspected drug lord Elias Valencia, the most significant arrest since the operation began.
Calderon's predecessor, Vicente Fox, Top of Formstarted out with enthusiastic U.S. applause for his own fight against drug trafficking. U.S. officials called the arrest of drug bosses early in his six-year term unprecedented, while Fox boasted that his administration had destroyed 43,900 acres of marijuana and poppy plantations in its first six months and more than tripled drug seizures.
Yet drug violence has spiked across the country in recent years, with gangs fighting over control of routes following the arrest of drug lords, authorities say.
Mexico has also continued to struggle with corruption among its law enforcement ranks. Garcia said authorities did not tell soldiers where they were being sent on raids and banned the use of cell phones and radios.
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