Minnesota Science
Vol. 45, No. 4
Integrated Controls Fight Sugarbeet Diseases
by Larry Etkin
Carol Windels is a unique researcher. She spends her time with plant pathogens in labs and sugarbeet fields in Crookston, the Red River Valley and west central Minnesota. She's the only professional plant pathologist based at a branch of the Minnesota Agricultural Experiment Station.
Windels has been at the Northwest Experiment Station at Crookston for six years, working on diseases endemic to the Red River Valley, and particularly on problems associated with sugarbeet stand establishment. "The previous common view was that wind, insects and seed bed preparation were important. Most producers didn't consider plant diseases, but we've found that diseases are one factor of the stand establishment problem," she says.
"I was working with one grower in 1986 who had not planted a field to sugarbeet in ten years, but he still had problems." She says that's because plant pathogens can be very persistent. Some can lay dormant in the soil for years, until proper conditions are present – say wet weather and an appropriate host for a water loving fungus.
Windels' research focuses on developing integrated controls for soil borne diseases of sugarbeet. This integration has her looking at resistant varieties, effective and safe chemicals, sanitary improvements in processing techniques, green plant residues and rotation effects. Because sugarbeets must be grown on a three to five year rotation, she also looks at the interactions of other crops on disease cycles. Small grains, particularly barley and wheat, command her attention as common rotation crops.
Windels' work has contributed to stabilizing several areas of the region which were poised to experience severe production losses from the spread of pathogens. Working with other University researchers, she's had one particular success in slowing the spread of a pathogen responsible for sugarbeet root rot. That was in 1988, when the practice of returning tare soil to fields was discontinued at the Southern Minnesota Beet Sugar Cooperative in Renville. Tare soil is now disposed of at designated sites where it won't be able to spread the pathogen to acreage previously not infected.
Tare soil is the field residue that is removed from sugarbeets when they are piled at receiving stations. It can carry the fungus Aphanomyces cochlioides, which is not yet widespread, but for which no chemical controls are available.
What made that development exciting for Windels was the speed with which the industry adopted the new disposal recommendations. "The clientele are progressive and ready to implement the latest research results into their operations," she notes.
Because of the effects of recent years' droughts, it's difficult to estimate a dollar value for her work to the industry, but she says, "I do know that we have much more grower awareness of disease problems, what to look for, and better cultural methods based on having more knowledge of plant diseases." In fact, the industry funds most of her research through its annual checkoff program, and growers provide ready access to their fields when research sampling requires.
PHOTO CUTLINE: Annual field day visitors at the Northwest Experiment Station,
Crookston, are eager for the information Carol Windels provides on sugarbeet
and rotation crop disease identification and control strategies.