The herbicide-tolerant crop revolution isn't leaving alfalfa growers behind.

Monsanto, the force behind the development of Roundup Ready corn and soybeans, recently licensed Roundup Ready technology for alfalfa to Forage Genetics, West Salem, WI. That company in turn will license the technology to other seed companies for development of Roundup Ready varieties.

Once those varieties are available, growers will be able to apply Roundup Ultra herbicide to their crop to control broadleaf weeds and grasses.

Mark McCaslin, a Forage Genetics alfalfa breeder, envisions the herbicide being applied during the establishment year and in later years, when tough-to-kill perennial weeds are often a problem.

"Roundup Ready alfalfa will give growers a lot more flexibility with weed control than they currently have," says McCaslin. "The beauty of Roundup is that it's very effective against a broad array of weeds. Plus, there's a wide window of application."

Even growers who currently use Roundup to kill old alfalfa stands will want to plant varieties that tolerate the herbicide, McCaslin believes.

"There are other herbicides that can be used to take out old stands."

The first Roundup Ready variety will be introduced, following regulatory approval, sometime after the year 2000, he says.

Forage Genetics is conducting field tests on Roundup-tolerant alfalfa this summer.

"The first plants carrying the Roundup Ready gene were initially screened in the greenhouse for tolerance to Roundup," says McCaslin. "The most-tolerant plants were then transplanted in the field in mid-May."

The plants were sprayed with Roundup Ultra in late June.

"The maximum labeled rate for Roundup application is 2 qts per acre, but we've been testing it at 4 qts per acre. We're seeing good tolerance at that rate of application," McCaslin reports.

After the first step of getting the Roundup-tolerant gene into alfalfa plants is completed, researchers will begin the longer process of variety development.

"During the plant breeding process, we'll ensure that new Roundup Ready products will have state-of-the-art pest resistance, forage yield potential, winterhardiness, forage quality, etc. - all of the traits that growers want and expect in new alfalfa varieties."

At the same time, Roundup Ready alfalfa should begin clearing regulatory hurdles.

Several major seed companies are expected to develop Roundup Ready alfalfas. At press time, Dekalb Genetics had signed on to work with the new technology and several others were expected to follow suit.

"It's our desire that this trait be very broadly licensed and incorporated into a broad array of varieties," McCaslin concludes.