The nation's toughest restrictions on a leading farm pesticide were adopted yesterday by Virginia's Pesticide Control Board, but environmental groups called the action too limited to prevent the deaths of bald eagles and other birds.

The board's 6 to 4 vote on the pesticide carbofuran, sold under the trade name Furadan, was its first major action since members were appointed by Gov. L. Douglas Wilder a year ago. Environmentalists and the chemical industry viewed it as a test of how tough the panel would be. Yesterday's action also sets a potential pattern for Maryland, where the legislature rejected a ban on carbofuran last session, and for other states.

Carbofuran is used to protect about 20 crops from insects, and is a leading pesticide for corn in the Chesapeake Bay area. Federal environmental officials estimate that it kills more than 2 million birds a year -- more than any other pesticide -- including bald eagles that die when they eat smaller dead birds. Virginia's board was spurred to act by the carbofuran-related deaths of 200 songbirds last spring in Essex County, southeast of Fredericksburg.

FMC Corp., which manufactures carbofuran, agreed to the restrictions to avert a ban. But its victory was potentially costly. The limits are projected to cut use of carbofuran in Virginia by more than one-half, partly because many farmers will turn to less-regulated products.

Board Chairman George Gilliam said the restrictions will reduce the risk of bird kills to "as close to zero as possible" without imposing a ban, which would have taken two years to achieve.

The vote "sends two messages: We're not afraid, not unwilling to deal very quickly with the controversial issues," Gilliam said. "It also shows we're pragmatic. We'll accept a compromise that gets us 90 percent of the way there rather than go down in flames looking for 100 percent."

But the state Department of Game and Inland Fisheries, environmentalists and four board members contend the restrictions are inadequate to prevent bird deaths, and they say substitutes for carbofuran are available.

"They just punted," said David Bailey of the Environmental Defense Fund. "Down the road, I don't see much credibility for this board on pesticide regulation."

Under the vote yesterday in Richmond, farmers in 29 eastern counties, including Prince William, must notify the state Department of Agriculture in writing at least five days before applying carbofuran on some fields. That is a first for any farm chemical in Virginia, and Farm Bureau lobbyist John Johnson called it a "very bad precedent." FMC will pay for state inspectors to make spot-checks of the fields to ensure proper use.

The board imposed a ban on use of carbofuran around the edges of some fields and required some farmers to attach a new spillage-prevention device to their planters. It banned use of carbofuran on some crops and required FMC to run an education program for farmers.

Maryland imposes no special restrictions on carbofuran, the eighth most widely used farm pesticide in the state, although some environmentalists hope a new pesticide advisory council will take up the issue now that Virginia has acted.

"We've been waiting to see what EPA does," said Charles Puffinberger, Maryland's assistant secretary of agriculture.

The Environmental Protection Agency, which has been studying the issue since 1985, is expected to decide next spring whether to restrict the use of carbofuran.