It took nine years, but Alan Lewis, a former member of the Maine Board of Pesticides Control, got what he wanted.

In December 1998, when the board was considering license applications for several varieties of biotech-enhanced, insect-resistant corn, Lewis said, "This board needs more than anecdotal evidence. ... The words I keep hearing are 'guess' and 'assume.' In my training as a scientist, the first thing we try to get away from is guessing and assuming."

Faithful to Maine law, the board turned down the applications because the applicants could not provide evidence there was a need for the products.

Fast-forward to 2007. In July, the pesticides control board reversed itself and voted unanimously (with one abstention) to approve seven varieties of insect-resistant field corn used to feed cows. The evidence of need was convincing.

A scientific study showed that the insects the corn is designed to resist were in fact active in Maine. Farmer after farmer testified that the biotech corn would make a difference in their dairy operations by increasing yields and cutting chemical pesticide use. Indeed, it was exactly the evidence Lewis, now no longer on the board, asked for nine years ago.

The final chapter in this saga, however, is still being written.

After approving the registrations, the board invoked its rulemaking authority and began considering rules governing the use of the corn products. Though the rules are still in draft form, there is cause for concern.

One of the proposed rules would require farmers to obtain a pesticide applicator's license before planting insect-resistant corn. Why? The 191-page study manual for the licensing exam has good information about chemical pesticides, but has no information -- none -- about planting insect-resistant corn.

Another rule would require plots of insect-resistant corn to include 660-foot buffers separating it from organic corn, seed corn and sweet corn.

Again, why? Organic growers are required by national organic standards to maintain their own buffers. Same for seed growers. The rule would only duplicate buffers already in existence. Much of the sweet corn sold in Maine grocery stores is already biotech-enhanced, so public safety isn't an issue.

The Maine Board of Pesticides Control took an important step when it considered the corn registration applications. It appointed a technical committee to analyze the scientific evidence supporting the products and to address the concerns of opponents. The 34-page report was full of information and analysis, all of it based on facts and science -- just what Lewis was looking for in 1998.

Though the report did not contain a recommendation on whether to approve the registrations, the conclusion was inescapable. Science supported the products. That and testimony from Maine farmers about the need for the products led to the unanimous vote for registration.

The draft rules take a step back from the science-based standard the board used to evaluate the original applications. Findings in the technical committee's report actually contradict the draft rules. The board's conclusion in 1998 that the products pose no health or environmental risks also conflicts with the draft rules.

Most disturbing is the abandonment of the "need" standard in the rulemaking process. It took nine years of data gathering and a scientific study to establish the need for the insect-resistant products in Maine. In the face of that, the board had no choice but to approve the products. Now, because a well-organized minority of Maine farmers and backyard gardeners is crying foul, the board is considering onerous rules that would make the products impractical to grow in Maine.

Why shouldn't the same standard of need apply to both groups -- those who want the products in Maine and those who don't? The proponents of insect-resistant corn did their homework, conducted studies and presented the board with a solid science-based argument for registering the products.

Now it's time for the opponents to do the same. If opponents believe rules are necessary to protect organic farmers or the public, it's their job to do the homework and make the case. As Lewis so correctly said, guessing and assuming aren't enough.

Douglas R. Johnson, Ph.D., is executive director of the Maine Biotechnology Information Bureau. www.mainebioinfo.org, which is funded by pharmaceutical and biotechnology companies, some of which manufacture bioengineered, insect-resistant corn.