Trouble has again struck the experiment in which live, genetically engineered microbes designed to retard frost were to be taken from a laboratory and sprayed on strawberry blossoms. It would be the first time such microbes would be released into the environment.

In the latest round of a controversy spanning three years, the Board of Supervisors of Monterey County, Calif., has said it is opposed to allowing the experiment, which has been approved by two federal agencies and a state board.

Further, the Monterey Bay Unified Air Pollution Control District board has declared that more tests are needed before the experiment can go ahead, and the board said it will go to court if necessary to make certain that the company performs additional tests.

Executive officer Lawrence Odle said the board is not opposed to agricultural projects of this type, but said this one has been handled badly by the company, which he said has given little information to local officials. "They were asking us to sign a blank check. My reaction is that I don't see this project going through, at least in this area."

On Wednesday, demonstrators also appeared with banners and signs in front of the company, Advanced Genetics Sciences (AGS) Inc., a small biotechnology business in Oakland. The experiment was intended to take place on a strawberry patch near Castroville in Monterey County.

To top it off, more than two dozen members of the Green Party in the West German Parliament have sent a telegram to the surprised chairman of the Monterey County Board of Supervisors. They objected to the experiment, saying they supported the local effort to ban the experiment and would soon introduce legislation in their own country to prohibit such experiments.

Critics, such as social activist Jeremy Rifkin, have said there is a risk in releasing a live, multiplying organism that has been altered by man and so far has been confined to the lab. Once released, the microbe cannot be recalled and may become a permanent fixture in the environment, critics said.

Douglas Sarojak, AGS director of product development and marketing, after fielding more than 30 calls a day for several days, said in a telephone interview that the issue is "most frustrating."

The most disturbing part, he said, is the feeling that "the people against us feed misinformation to others" for the purpose of setting off emotional reaction rather than discussions about the science of the project. "There are some real, concerned citizens that have questions. But I do think some irrational people would just as soon that biotechnology would never see the light of day."

He said the experiment, a "pre-preliminary study," has jumped through more official hoops than any review on record, producing more data and scientific support for its proposal than any comparable experimental use permit.

The company has already spent "a few million" dollars in trying to get the experiment approved. Initially, it submitted its proposal to the National Institutes of Health panel that has reviewed biotechnology projects.

Then, the Environmental Protection Agency reviewed the experiment, asked for more studies, and finally approved it. The EPA was immediately sued by Rifkin and the Foundation on Economic Trends, which contended that the decision was "arbitrary and capricious" because the EPA's methods to determine the risk of such experiments have not been worked out. The suit is pending.

Next, the California board that reviews environmental proposals approved the experiment. Now, Monterey County authorities are diving into the issue, starting from a position of anger at not being informed earlier about the proposed experiment.

County Board Chairman Sam Karas said the board was seeing what legal means are available to eject the experiment from the county.

In the experiment, laboratory-altered microbes would be applied to strawberry blossoms to determine whether they can stop the formation of crystals and protect the budding fruit from frost.

Huge sums are lost annually in frost damage caused by a bacteria that naturally covers leaves of most plants. The "Frostban" bacteria would attempt to displace the bacteria that usually inhabits the plant.