Many soybean farmers don’t realize their fields may be a buffet for soybean cyst nematodes, despite the use of SCN-resistant soybean varieties.

These microscopic, parasitic worms lurk beneath the soil and can feed off soybean plant roots before any above-ground crop damage is noticed. By then, the SCN population has grown much more numerous and stronger, becoming difficult to control as well as a huge economic threat to soybean farmers.

“In recent years, an increase in aggressive SCN populations, which can feed and reproduce on resistant varieties, has been widely documented throughout the north central U.S.,” said Sam Markell, Ph.D., associate professor and Extension plant pathologist at North Dakota State University.

Soybean farmers are used to selecting a resistant variety and assuming SCN will be managed in their field. A survey of 1,100 soybean farmers across 17 states, conducted in late 2015, identified SCN as one of the biggest foes of soybean crops. Of those surveyed, 63 percent indicated they were growing SCN-resistant soybean varieties, while the majority of respondents knew only “a little” or “nothing” about SCN. Worse yet, 66 percent were not scouting or sampling for SCN.

Syngenta collaborated with five land-grant universities to design the survey.

“Using the same source of resistance for more than 25 years has reduced the efficacy today, in a similar way as if we used the same herbicide over and over again,” said Greg Tylka, Ph.D., professor and Extension nematologist at Iowa State University.

The SCN populations are changing all around the country, but the way we manage SCN is not. “We are on the front end of a crisis similar to herbicide-resistant weeds and even costlier to farmers,” said Shawn Conley, Ph.D., professor and Extension agronomist at University of Wisconsin-Madison. “From an agronomic point of view and to keep productivity high, this is alarming.”

Like herbicide resistant weeds, the looming SCN crisis will not be averted if everyone doesn’t come together for a common goal.

With Resistance Fighter, Syngenta and key universities were joined by grower groups to educate farmers, as well as seed and herbicide suppliers, how to manage and delay the looming threat of herbicide resistance. Diversity was the key to success.

“The time is right to do something similar for SCN,” said Palle Pedersen, Ph.D., head of Seedcare product marketing for Syngenta. “We are standing at the edge of a cliff right now and none of our tools can do it alone.”