There are definite ways to minimize the risk of unwanted gene flow so farmers can continue to successfully produce for organic, export or other sensitive markets,” says Dan Putnam, University of California Extension forage agronomist.

First, buy certified seed, he says. “In the case of growing for sensitive markets it’s particularly important, because then you will be assured that what you’re planting does not have the Roundup Ready trait.”

Growers of crops sensitive to genetic engineering (GE) should test seed to ensure it’s “non-detect.” Or buy seed with the new Association of Official Seed Certifying Agencies designation that’s given to seed grown with strict isolation distances to prevent contamination, Putnam says. Test strips for seed or hay to detect the Roundup Ready trait are inexpensive and easy to use.

Also be sure that planting and baling equipment are cleaned so Roundup Ready alfalfa isn’t moved into GE-sensitive fields.

Keep good records so non-GE hay is kept separate from a transgenic crop, he adds. Again, test strips can be used to assure buyers of the crop’s non-GE status.

Putnam also advises boning up on gene flow and learning just how much or little contamination risk there is in hay crops vs. seed crops.

“In seed, gene flow is a significant issue in order to protect seed purity; with hay crops, it’s not as much of a factor. It’s a risk but a fairly small risk. The question then is: How do you further minimize risk?”

One way is to communicate with neighbors. If Roundup Ready alfalfa is grown in your area, find out where and how far away.

“At about 165’, Larry Teuber at UC-Davis measured the probability of gene transfer from a hay field to seed field at about 0.25%. At 500’, it goes down to near zero.

“But 0.25% is a worst-case scenario for a seed crop, not hay,” he says. “In hay, if 99% of the crop is harvested before seed is produced, gene flow risk goes from 0.25% to 0.0025% at 165’. If all of the crop is harvested, with no remaining seed-producing plants, gene flow goes to zero.

“A lot is under the control of the hay grower. I’ve grown Roundup Ready alfalfa varieties side by side within a few feet of conventional for three years in our trials with zero gene flow, since we harvest regularly before significant flowering.”

For hay crops to be permanently contaminated, viable seed would need to fall to the ground, germinate and contribute to the next hay crop – a low-probability event, Putnam says. The potential risk is also proportional to the degree of tolerance, which depends on the markets. Some may be sensitive to very small amounts of contamination; others may not be as sensitive.

“The main thing for people who are growing Roundup Ready alfalfa is to be knowledgeable about their neighbors’ needs and as to where they might have an inadvertent effect on neighbors’ production,” he adds.