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Southern root-knot nematode costly to soybean farmers

A plant pathologist is mapping the spread of southern root-knot (SRK) nematode to increase awareness of the pest.

Travis Faske is with the University of Arkansas.  “If soybean cyst is an embezzler, you can’t quite see the symptoms then root-knot nematode, or the southern root-knot nematode is dramatic,” he says. “If a susceptible soybean plant is in that field, there’s a high population density of root-knot, and we have the right conditions, the plants will die.”

He tells Brownfield there are limited options available to control the pest, resulting in late detection. “The population density is higher and then they really have a more severe problem at that point,” he says.  “Using a soybean variety that has a moderate level of resistance is your best option moving forward, or trying to rotate with a crop that is a non-host or a poor host.”

He says farmers who have high levels of SRK should consider planting peanuts, if possible, which are not a host, for two years, then planting an SRK-resistant cotton variety before returning to soybeans.   He recommends growing a later-maturing Group 5 soybean rather than a Group 4.  Faske says corn and most cover crops are hosts, allowing infestations to thrive. 

Faske says the mapping project found the pest is problematic for growers beyond the southern U.S. “Now it is into the Midwest,” he says. “If we don’t take some action now, it’s going to be just like soybean cyst and spreading rampant.”

Faske says southern root-knot nematode has been found as far north and west as Adams County, IL (western Illinois) and cost soybean farmers more than 13 billion bushels in 2022.

AUDIO: Travis Faske, University of Arkansas