Gary Carmichael thinks a lot of alfalfa growers don’t realize how much money they’re losing to weeds, especially in the seeding year.

“We didn’t, either, until last year when we did Roundup Ready,” says the Evart, MI, commercial hay grower.

He seeded 165 acres of Roundup Ready alfalfa on May 1 and sprayed the fields with 1 qt/acre of Roundup a month later, when weeds – mostly pigweed, ragweed, witchgrass and foxtail – were 2-3” tall. He applied an insecticide and a foliar fertilizer with it. The first cutting began July 12, and irrigated fields yielded 2¾ tons of dairy-quality hay per acre from three cuttings.

“The first cutting was spotless and uniform, and where it had adequate moisture, it was almost knee-high.”

Carmichael grows 2,000 acres of alfalfa, grass and alfalfa-grass mixes, and sells to a variety of clients, including dairy producers who want pure alfalfa. But harvesting high-quality hay from new spring seedings has always been a challenge because of weeds.

The preplant herbicide he used for several years doesn’t work well if it rains too much or too little, and other postemergent products stunt alfalfa and don’t kill as many weeds as Roundup, he says.

Carmichael would have tried Roundup Ready alfalfa when it was reintroduced in 2011, but thought seed prices were too high. Prices came down in 2012. With volume and other discounts, his cost, including Monsanto’s technology fee, averaged $285 per 50-lb bag. That was about $100/bag above the cost of comparable non-Roundup Ready varieties, he says.

He seeded 18 lbs/acre, so his seed cost was just over $100/acre. He plans to make annual Roundup applications as needed, and thinks the cost was reasonable when spread over the stands’ useful life. Later, when a stand thins, grass seed could be broadcast or no-tilled in for a different hay market.

“Guys who planted Roundup Ready alfalfa in 2005 made it last eight to 10 years, so I’m thinking that might be a possibility,” he says. “There may be a direct relationship with weed control and the alfalfa plant’s longevity.”

With hay supplies tight and prices expected to stay high, he thinks some Midwestern farmers may seed more alfalfa this spring. For them, Roundup Ready would be a “great weed-control option.

“It’s a tremendous way to get a good yield right away and not struggle through that seeding year,” Carmichael adds.

Read on for more on Roundup Ready alfalfa: