Cercospora leaf spot relief spelled 'Provysol'

WAHPETON, N.D. -- Sugar beet farmers in the southern Red River Valley and Minnesota will have a rescue from cercospora leaf spot -- a disease that cost southern growers tens of millions of yield and production losses in 2018.

Mike Metzger, vice president of agriculture and research for Minn-Dak Farmers Cooperative in Wahpeton, N.D., is grateful that his co-op and Southern Minnesota Beet Sugar Cooperative at Renville, Minn., received Section 18 emergency Environmental Protection Agency approval to spray Provysol, a new systemic fungicide from BASF, on the 2019 crop when the leaf “canopy” closes, probably sometime in early July. Photo taken June 12, near Moorhead, Minn. (Forum News Service/Agweek/Mikkel Pates)

WAHPETON, N.D. - Sugar beet farmers in the southern Red River Valley and Minnesota will have a rescue from cercospora leaf spot - a disease that cost southern growers tens of millions of yield and production losses in 2018.

The U.S. Environmental Protection Agency on June 7 approved a Section 18 Emergency Exemption for the registration of the trade name Provysol, a systemic fungicide from BASF to control CLS. The disease has been intensifying since 2016, spreading from the south in Minnesota and North Dakota.

CLS is a microscopic spore that lands on the sugar beet leaf, germinates and produces a toxin that kills part of the sugar beet leaf. It causes big reductions in sugar beet quality and overall tons per acre.

A Section 18 Emergency Exemption is a limited-time registration that allows for the use of an unregistered pesticide in defined geographic areas for a finite period of time once the EPA confirms that the situation meets the statutory definition of emergency condition. The effective period of use for this Section 18 label started May 31 and runs through Sept. 25. It will have to be tank-mixed with another fungicide, such as copper.

A tip of the hat


Mike Metzger, vice president of agriculture and research for Minn-Dak Farmers Cooperative, who was instrumental in completing the application, said the exemption is unusual in that the product is not yet used on other crops. Metzger's shareholders lost $40 million to the disease in 2018, with more than 90 percent of acres affected at some level, with yield losses ranging from 10% to 40%. Even co-op members who didn't suffer yield losses saw impacts because of factory inefficiencies.

The exemption this year will apply only to beet producers in certain counties in Minnesota and North Dakota, but also is limited to members of only the two southernmost co-ops - Minn-Dak Farmers and Southern Minnesota Beet Sugar Cooperative at Renville, Minn.

Officials of American Crystal Sugar Co., in Moorhead, Minn., cooperated with the application but none of their growers will benefit this summer. Crystal kept itself out of the final application because officials knew they had little damage in northern factory districts and overall damage needed to be 20%. If Crystal's acres had been factored in, it would have lowered the percentage of acres damaged.

"A tip of the hat to American Crystal," Metzger said. "They recognized our need and they were kind enough and generous enough to be able to withdraw themselves from the (Section) 18 to ensure that Minn-Dak and Southern Minnesota would be able to move forward."

It's the humidity

Brian Ryberg, owner of Ryberg Farms of Buffalo Lake, Minn., and a board member for Southern Minnesota Beet Sugar Cooperative, said cercospora problems have arisen with a more humid climate. In 2018, farmers faced a "perfect storm" of excessive rains and compounded losses due to CLS resistance to fungicides.

Five years ago, growers sprayed three to four times a year and got control of CLS, Ryberg said. "In the past year, most everyone sprayed six to eight times and didn't have control," he said. Farmers paid $150 to $180 an acre with "just very poor results." He says the company lost 2 percentage points of sugar and about 5 to 8 tons of yield per acre. "It's just a big number," he said.

Individual farmers had tried to convince the co-op to allow them not to harvest a crop that they didn't think was worth harvesting, but the co-op needed the beets. "We had to convince people we needed to harvest every beet we can," he said, noting that farmers had to weigh crop insurance issues.


The Southern Minnesota co-op aims to produce 3.6 million tons of beets to run through its Renville, Minn., plant and in 2019 was able to muster 2.6 million tons. As a result, the average beet payment was $27.50 per ton, which is less than the $45 per ton or better payment farmers are looking for adequate profitability.

Crop leaf canopies usually close about July 4, creating an environment that favors the disease and prompts spraying, Metzger said.

Ken Deibert, technical service representative at BASF, said that by protecting the inner leaf tissue in early growth stages with a preventative application of Provysol fungicide, growers can "set their crop up for success and increase effectiveness of subsequent fungicide treatments in the future."

Rules, locations

Provysol fungicide may be applied by ground or air equipment at a rate of 5 fluid ounces per acre. Up to two applications may be made, with an interval of at least 14 days. The annual limit is 10 fluid ounces per acre. People may not enter a treated field within 12 hours. Harvest must come at least 21 days after the last treatment. Any unused product must be returned to the distributor or BASF Corp. after Sept. 25.

Growers interested in purchasing Provysol fungicide can find it at numerous locations. Specifically, providers include:

Minnesota: Anderson Agri Sales, Callaway; Barrett Farm Supply, Barrett; Belgrade Coop, Belgrade; Bird Island Soil Service, Bird Island; Central Counties Cooperative, Atwater; CHS New Horizons, Herman; CHS Prairie Lakes, Elrosa and Hoffman; C-W Valley Cooperative, Comstock; Elbow Lake Coop, Elbow Lake; Farmers Coop Oil, Clara City; Farmers Union Oil, Montevideo; Farmers Union Oil Co., Breckenridge; Farmward Cooperative, Morto; Danube, and Springfield; Glacial Plains Coop, Murdock and Clontarf; Hefty Seed Co., Olivia, Hancock, and Breckenridge; Krabbenhoft Seed & Supply, Sabin; Minn-Kota Ag Products, Breckenridge; Prairie Grain Partners, Clarkfield; Prairie's Edge Agri-Service, Sabin; Prinsburg Farmers Coop, Prinsburg; Trico Ag Service, Hancock; United Farmers Cooperative, Hector; Brownton, and Winthrop; Valley Ag Partners, Rothsay; West Central, Foxhome; Western Consolidated Coop, Holloway and Kensington; Wheaton Coop Elevator, Wheaton; Willmar Aerial, Olivia; CHS Inc., Glyndon.

North Dakota: CHS Dakota Plains Ag, Kindred; Colfax Farmers Elevator, Colfax; Maple River Grain & Agronomy, Casselton; Mooreton Chemical, Mooreton; Nutrien Ag Solutions, Wahpeton.


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