The sky fell a long time ago for those who feared the introduction of genetically modified crops into Maine. For at least a decade, the state's farmers have grown Roundup Ready canola, corn and soybeans as well as LibertyLink corn -- all plants that have been bred through biotechnology to be resistant to herbicides.

Last week, another significant barrier finally fell when the state's Board of Pesticides Control, or BPC, approved the use of Bacillus thuringiensis, or Bt, corn. That approval was hotly contested by organic farming advocates and came a decade after the first effort by biotechnology companies to gain approval of the corn's use in the state. (A small experiment in growing Bt potatoes here in the last decade failed when the market for them didn't materialize.)

Bt corn is grown as feed for animals and contains normally soil-borne bacteria that kill insects that can decimate a corn crop; insects try to eat the corn and die, instead. Conventional farmers argued that growing it could cut their pesticide use and costs, increase yields and thus give them a competitive edge at a time when farming in Maine is more challenged than ever.

Organic farmers have maintained for years that use of Bt corn would lead to the evolution of pesticide-resistant insects. Equally worrisome was the issue of so-called "genetic drift" -- unlike the earlier experiment with Bt potatoes, which self-pollinate, one corn plant pollinates another. And that raises the specter of Bt corn pollinating organic and non-Bt corn -- a kind of genetic trespass and pollution that scared organic growers who make a living on the certified purity of their crops.

The state needs to do everything it can to help both agricultural sectors, conventional and organic, thrive. The use of Bt corn may well help conventional farmers but it can also harm a robust and growing segment of our state's farming community, organic growers. Conflicts between adjacent farms that grow both kinds of corn are bound to happen; those conflicts could easily escalate into lawsuits. Farmers are more likely to be able to handle a plague of grasshoppers than a plague of lawyers, and time spent in a courtroom is time not spent in the field.

That elevates the importance of ensuring that proper rules are in place to control the interactions between Bt corn crops and organic crops and that rules regarding the safe and ecologically appropriate management of the corn are promulgated and enforced.

The Board of Pesticides Control should ensure that all farmers using the corn are trained in its safe management. Buffer zones will need to be established between the crop and adjacent farms growing organic corn; that will likely entail direct discussions between farmers that should be facilitated and overseen by the board. Federal requirements that 20 percent of a farm's acreage be planted to conventional corn as a "refuge" for insects must be followed. Compliance with these rules will require that farmers file annual reports.

All this will necessitate strong enforcement and oversight by the board, which will be a challenge, given that it's part of an underfunded and understaffed state Department of Agriculture. Yet if there's one place where that kind of state oversight is positively essential, it's in the aftermath of approval for a crop that's never been grown in this state before and whose potential, and perils, are equally great.