Run the numbers and you see ag biotech went through startling growth with the 1996 introduction of cotton and corn with Bt genes built in, then actually decreased in 2000. Chances are, that's a temporary skid.

Gerald Carlson, North Carolina State University agricultural economist, speaking at the Southeast Vegetable and Fruit/AgTech 2000 Expo in Greensboro, N.C., said Roundup Ready crops captured 52 percent of the nation's acreage in 2000, down from 59 percent in 1999. About 29 percent of the nation's corn crop was planted in Bt varieties in 2000. His numbers show about 40 percent of the cotton crop in Bt varieties.

He says the technology fee for planting Bt cotton dropped to $29 per acre, from $32. The Bt corn fee also dropped, to $6 to $8 per acre, from $10. The fee for Roundup Ready soybeans bumped up to $6 from $5 per acre.

"But the cost of Roundup herbicide decreased 30 percent in 2000. It's looking better to farmers now that fees are coming down," Carlson says.

Carlson figures biotech crops boost yield. His figures show Bt cotton pushing yields six percent, Bt corn three percent in 1998-1999 after showing nine to 10 percent in 1996-1997, and Roundup Ready soybeans improving yield two percent after early-on registering a slight one percent yield drop compared to conventional varieties.

Yield jump correlates to insect population. "If you have insects, you get a yield gain. Southwestern corn borer numbers were fairly high in 1996 and 1997, which is why the yield increase for those years was nine to 10 percent. From 1998 on there have been very low years for Southwestern corn borer. They're not sure why. And Roundup Ready wasn't in the best soybean varieties the first year. Now that it is in the better varieties, it looks like a one to two percent yield gain," he says.

Carlson says Roundup Ready soybeans alone saved farmers $220 million in 1998 and let them use 16 million pounds less active ingredient of herbicides, reducing pesticide usage 19 percent compared to 1995.

Biotech benefits to farmers are obvious, he says: increased average yields, less yield variability, pesticide savings, labor savings, prevention of insect resistance.

Less obvious are what he calls off-site benefits. "Farmers have been able to switch to less-persistent herbicides. They've replaced them with Roundup, a fairly innocuous herbicide that breaks down fairly quickly. There's less tillage and soil erosion associated with herbicide-tolerant crops, so there's less runoff and less sediment in the streams," he says.

"Also, off-site, more related to Bt corn and cotton, there less pesticide drifting. Farmers are better able to manage insect resistance. That's why a lot of farmers initially got into it. There are fewer insecticide sprays, less active ingredient being used."

On the negative side, industry watchers worry about Bt building insect resistance, a reason to pay close attention to refuge requirements for non-Bt acreage. Herbicide tolerance spreading to weeds could become a problem, too, Carlson says.

"This has already been seen in canola in Canada and also in rice, with a lot of the near weed relatives. This is going to have to be watched closely. There are real problems here from the farmers' point of view."

He thinks the great potential for biotech crops lies in developing nations. "The problems we're having with StarLink corn shouldn't distract from the potential in other countries. Seeds are economically neutral. You don't have to be a big farmer to do it. This is where the big potential is. Here in the U.S., we're a wealthy nation. Europe is a lot of relatively wealthy countries. They can afford not to use this technology. Developing countries can't afford not to use it," Carlson says.