The government's effort to wipe out marijuana growing was so successful last year that more pot was burned than officials thought existed.

"Obviously, our estimates of how much [marijuana] is growing in the U.S. will have to be revised," said a spokesman for the Drug Enforcement Administration, which worked with 25 states last year to find and burn marijuana crops.

"In 1982, 38 percent more domestic marijuana was eradicated than was previously believed to exist," a new DEA report said. The program exterminated 2,590,388 marijuana plants, or about 1,818 tons, in 4,657 plots.

The government once estimated that only 900 to 1,200 tons were grown here. The DEA report has now raised that estimate to at least 18,000 tons.

For years the government's estimates have been criticized as being far too low. The current report acknowledges that previous estimates were low, raising the new estimate spectacularly and making them far higher than other groups estimate.

The National Organization for the Reform of Marijuana Laws (NORML) estimates that 8,000 to 10,000 tons of marijuana, worth about $10.4 billion is grown in the United States.

"We think the DEA numbers are high, but we are glad to see that our numbers have finally been confirmed by the government," said George Farnham, president of NORML.

"The NORML position always has been that with emergence of domestic growing of marijuana in such quantities is has become futile to continue even to try to eradicate it . . . . It is now clear, in last year or two, that growing it is so out of control and continues to spread at such an alarming rate, the only sensible thing to do to control it is to regulate and tax marijuana."

Bills have been introduced in two states, Oregon and Pennsylvania, to do that, and Farnham said three other states may follow.

The amount of marijuana destroyed varies from state to state, and the DEA report states that in some states as much as 50 percent of the marijuana believed to be growing was wiped out.

Virginia, with about two tons of marijuana destroyed, was said to have had 50 percent of its crop destroyed. California and Oregon crops were said to be 40 percent destroyed.