When you buy hybrids with traits for corn borer or corn rootworm protection, you sign an agreement. It's more than just a formality. You're agreeing to comply with certain regulations, which includes planting hybrid that doesn't have the trait on your refuge acres. How much refuge needs to be planted and where it needs to be located is spelled out by the company that sold you the product.
An environmentalist told Indiana Prairie Farmer in the late 1990s that insects would be resistant to the Bt technology in two years, and it would be useless. Fortunately, his timetable was off. Many traits are still valuable and providing resistance. However, 15 years later, resistance or tolerance, depending upon who you talk to, has developed to one of the early events for corn rootworm control. It's been confined to the Western Corn Belt so far, spilling over into Illinois, and is worse on continuous corn fields where the same trait was used every year. It's not known if farmers who didn't plant refuge contributed to the development of resistance.
However, it is known that many farmers elected not to comply over the year. Some were so brazen as to say so at seed meetings and field days, and wonder why anyone else would do it either. Needless to say, enforcement was lax.
Now refuge in a bag would seem to be the solution to the problem. However, Dave Nanda, director of genetics and technology for Seed Consultants, Inc., isn't sure if 5% of a refuge hybrid mixed in with the traited hybrid is enough to prevent development of resistance long term.
He is encouraged by the fact that recent surveys show more farmers are abiding by the refuge guidelines. No doubt refuge in a bag is playing a part. In the latest numbers, only 10% admitted to not planting refuge where required.
Nanda presents a full discussion of the need for refuge and how to accomplish it in the April issue of Indiana Prairie Farmer.