Few people appreciate the importance of genetic change as well as farmers. Después de todo, weve been cross-breeding to build better plants for eonsgoing all the way back to prehistoric communities thousands of years ago. The crops we grow today arent anything like the ones our ancestors found in the wild and decided to cultivate. And thats true even without recent advances in biotechnology.

So natural selection is a tool weve used to our advantage for longer than anyone can remember. But it can also work against us when the pests who prey on our crops develop resistances to the obstacles we throw in their path.

Thats why the federal government requires farmers who plant bt corn to reserve 20 percent of their corn acres for non-bt varieties. If nobody planted anything but bt corn, corn borers would suffer mightily in the short term but come back with a vengeance in the long term. They would evolve immunities to what has been a fantastic technology that helps us boost yield and reduce sprays.

The good news is that the vast majority of farmers are complying with these rules, which are established by the Environmental Protection Agency. A new study by the Center for Science in the Public Interest, a consumer-advocate group, shows that more than 80 percent of farmers who plant bt corn abide by these guidelines.

Por supuesto, this is not what the news media chose to focus on. We were treated to a series of glass-half-empty stories about how a minority of biotech farmers arent in compliance. And thats the bad newsAbout one in five bt-corn farmers are not using this biotechnology properly.

Thats not glass-half-empty. Thats glass-one-fifth empty.

Aún así, lets get something straightWe ought to have close to 100-percent compliance when it comes to these rules. Theyre in place for our common goodand so this form of agricultural biotechnology can remain helpful to us for years to come.

Theres no evidence so far that corn borers are developing resistance to bt corn. Yet if we fail to improve upon this 80-percent mark, were going to invite intrusive government regulations. Esto, de hecho, is exactly what CSPI wants. Noncompliance on this scale shows that current regulations arent up to the task, said Gregory Jaffe, director of CSPIs biotechnology project, in a press release. Both the EPA and the biotech industry must do more to make sure that farmers meet these very basic obligations, so that the benefits of this technology wont be squandered.

While I dont believe we need bureaucratic busybodies tramping through everybodys cornfields, I do think people in the business of selling bt corn seeds need to remind their buyers of the 20-percent refuge rule. Ive been a farmer-seed salesman and I understand the reluctance to tell customers how they should use what theyve purchased. Por otra parte, we want the people who use our products to use them as effectively as possibleand the effective use of bt corn also means growing non-bt refuges.

Reminding farmers of this obligation should be no more intrusive than car salesmen telling customers that they ought to change their oil every 3,000 millas. Most of us already know this, but a handful of us may notand were all better served when everybody understands the rules of the road.

Having said all that, the news about compliance is actually better than CSPI lets on. Its study examines farms rather than acres. It turns out that small farmers are less likely to comply with the EPA rules than big onesso it follows that compliance, when tracked against acreage, is actually higher than 80 por ciento.

So thats even more good news. The bottom line is that the vast majority of farmers are complying with these important rules and that an even vaster majority of bt-corn acres are also complying.

We can do better and we will do better. But were also doing pretty well right now.