There was actually less herbicide use with the GMO alfalfa. “One grower used Roundup only twice in two and a half years.”

19 out of the 23 surveyed graded it an A.

RR alfalfa planting seed is twice as expensive as conventional varieties with the technology fee.

However, Putnam said California growers are notorious for planting too much seed, seeding conventional alfalfa at rates of 35 to 40 pounds per acre when 25 pounds or less will give the same stand.

Using a seeding rate of 20 pounds per acre and the cost of herbicides other than glyphosate compared to glyphosate in rotation with other herbicides, he said RR alfalfa is more economical than conventional alfalfa over the life of a three- or four-year alfalfa stand.

“Some growers claim their stands last longer when not damaged by conventional herbicides. Jury is still out on that,” Putnam commented.

While those trying to keep RR alfalfa off the market contend it will contaminate organic hay and seed production, Putnam said the issue of RR alfalfa in the export market is much more important to California where 7 percent to 8 percent of the hay is exported. Less than 1 percent of California’s hay production is organic.

Much of the state’s export hay comes from the Imperial Valley where growers, seed producers and Monsanto have agreed to a ban on RR alfalfa as part of a stewardship program. The gene flow issue is another reason for the RR alfalfa ban in Imperial because seed fields are in very close proximity. It would be difficult to impose the industry-established 2.5 mile isolation for RR seed fields.

“Imperial Valley is a unique situation. They export hay and seed from a relatively small, isolated valley where you have hay and seed right across the road from each other. You also have growers who produce forage and seed from the same stand,” he said. Gene flow is greater there than any other place in California, added Putnam.

The state forage specialist said it was a “wise move” not to have GMO alfalfa there until “growers can understand how to deal with it in the Southern California desert.”

Detractors contend that the introduction of RR alfalfa will eventually eliminate non-GMO alfalfa. Putnam disagrees. Gene flow, he said, can be managed with good stewardship.

Overall, advantages of RR alfalfa far outweigh the disadvantages on Putnam’s list of pros and cons.

hcline@farmpress.com