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Roundup sugar beets a success for Wyoming Sugar

Written by Christy Hemken

Casper – Part of any discussion on weed control, the recent Wyoming Weed Management Association annual meeting was no exception when it came to discussing the use of Roundup herbicide on an ever-increasing list of glyphosate-tolerant crops. 

Wyoming Sugar’s Chuck Duncan, who has spent the last 38 years working with sugar beets, was present at the meeting to give an update on what his company found in their research with Roundup Ready sugar beets last summer in the Big Horn Basin.

“When I started many years ago, I would never have believed we’d have something like Roundup Ready sugar beets,” he said as an introduction. Last year Wyoming Sugar decided they wanted to increase their acreage in the Big Horn Basin, and that one of the ways they could do that was through the introduction of Roundup Ready sugar beets.

“We had discussions with Monsanto and the seed companies, in which we decided it might work so then we met with the Wyoming Sugar board, the Washakie Beet Growers Association the Sugar Industry Biotech Council. We were able to get everybody on board and got this thing started,” said Duncan.

“We started in the spring with watching the stands to see how they’d turn out. When we stared spraying we found some of the plants died from the spray, but in a very small amount, which was less than one percent,” he began to explain.

“Most of the time the sugar beets will jump out and grow and look wonderful and are way ahead of the weeds, but sometimes the weeds were way ahead of the sugar beets, which becomes a major problem and would be a disaster if we didn’t have Roundup,” he said.

Duncan said sprayers could run from 12 to 20 miles per hour to apply the herbicide. As part of their research, in some of the fields tarps were laid so the grower could see exactly what kind of control he was getting on the crop.

The applicators used 32 ounces of Roundup and 17 pounds of ammonium sulfate per hundred gallons of spray, which was the recommendation from Monsanto and was required in all of the applications. “The ammonium sulfate increases the control of Roundup on the weeds,” said Duncan.

In some of their side-by-side trial fields comparing conventional sugar beets to a Roundup Ready variety, Duncan said after the conventional field was sprayed and had gone through its “chemotherapy,” they were yellowed and set back, while the Roundup Ready field remained lush and full with no adverse reaction.

“But not all varieties are equal, and there’s a difference between them,” he noted. “That’s something we’re going to have to work on to find out what the disease package is and how well they’ll emerge in the spring.”

Duncan said Roundup didn’t control Canadian thistle, but did set it back. “Where the flower came out it quit growing and turned yellow but the old leaves stayed green and it took a long time for them to dry up. That was a concern for us.”

However, he said whitetop burned very heavily and was taken out 100 percent. The Roundup also controlled sunflowers and kochia “that you couldn’t have gotten out with a hoe,” according to Duncan.

The Roundup also didn’t kill volunteer Roundup Ready corn, but Duncan assured that wasn’t a problem. “We can put Select in the mix and take care of it, but this year we chose to use just Roundup in our research. Wyoming Sugar was the only one in the whole world that tried this last year and so we wanted to be sure we knew exactly what was happening on it.”

“Monsanto didn’t think we could control alfalfa, but it burned down very well and we were impressed,” said Duncan. “We learned that we can control alfalfa, if that’s a concern. We didn’t control it 100 percent, but what did escape was insignificant.”

Duncan stressed the importance of eradicating the weeds while the beets are small. “If the weeds get too tall the beets are still there, but the competition from the weeds reduces the size and growth of both the beet tops and roots.” Although Monsanto recommends an application when the beets reach three inches, Duncan said he thinks they should be sprayed when they’re one inch tall.

Obviously, some consideration needs to be given to neighboring crops while spraying Roundup. “You can spray without doing damage to an adjacent crop,” said Duncan, citing a field where they waited until the breeze was right and thus had no damage to the adjacent barley. “It was very well done.”

However, Duncan said the right breeze is key. “We had a case where the applicator sprayed when it was absolutely calm. You need a little breeze moving the herbicide from the conventional to the Roundup Ready crop because we took out a few plants even in the second row over because the Roundup was just hanging in the air.”

“Another thing we learned about Roundup Ready is that some of the plants turn yellow at harvest, but the crop was nice,” said Duncan.

“We’re looking for clean beets going into the truck headed for the piler and being put into piles so they store well,” he continued. “If those weeds are not there to block the flow of air there are considerably better storage conditions in the pile. We recognize you still have to fight mud and the neighbor who didn’t have Roundup beets, but we had a good harvest.”

“Overall, we learned this is a great tool and an exciting time for the industry, and it’s very comparable to the introduction of monogerm seed 40 years ago,” concluded Duncan.

University of Wyoming Research Scientist Andrew Kniss worked with Wyoming Sugar in their research and compiled the input costs and production after harvest. The research was conducted on 20 paired fields managed by 18 growers. “The paired fields were in similar locations and managed in the same way by the same grower,” explained Duncan.

With the cultivator or ditcher, the conventional field was driven across 1.8 times and the Roundup Ready field was only crossed .9 times. The sprayer traveled across the conventional field 2.5 times, and across the Roundup Ready field 2.2 times. The cost of conventional herbicide was $61 dollars on average, while the Roundup cost $19 on average.

“When you take into account the Roundup Ready royalty, cultivation, herbicide, application and hand labor, the cost was $177 on conventional versus $87 on the Roundup Ready in paired fields,” said Duncan.

The conventional beets produced 22.6 tons per acre, “Which we would say is reasonably good for an average of all 20 fields together,” he commented. However, the Roundup Ready beets produced 24.6 tons per acre.

The sugar content on the conventional varieties came in at 16.5, while the Roundup Ready ended up at 17.1, “Which is impressive,” he said. “Both things were better in the Roundup Ready fields on the 20 fields paired.”

“When you take the weed management savings, which were $90 per acre, and the increase payment, which was $133 per acre, the grower made $223 per acre more on average on those fields,” said Duncan. “Keep in mind there were some good and some bad, but the average turned out $223 more under Roundup Ready sugar beets.”