Importance of Soil Testing This Fall for SCN

Photo courtesy Guiping Yan, North Dakota State University
Photo courtesy Guiping Yan, North Dakota State University


Soybean cyst nematode (SCN) is the number one yield-robbing pathogen in the U.S.

As we prepare for the 2020 season, MSU Nematologist Dr. Marisol Quintanilla says we could be spreading SCN more since a lot of crops are harvested in wet, muddy conditions.

“With mud sticking to tractors and farm machinery, nematodes are moving around with the dirt and mud,” said Quintanilla. “It’s likely that [you will be] moving them around from infected fields to clean fields even more than past years.”

It’s always a good idea to do soil testing, but Dr. Quintanilla says it’s important to test for SCN to make effective management decisions, especially if your soil tests high for SCN.

“It might be a best management decision to plant corn, not soybeans, the next year, or to plant a source of resistance that the nematodes are not adapted to,” she said. “It might help to choose which variety to buy.”

Before SCN was discovered in Michigan, some farmers experienced yield losses of up to 80 percent. Quintanilla recognizes that it’s because SCN a strong pathogen with the ability to quickly reproduce.

“The soybean plant becomes a slave for soybean cyst nematodes,” said Quintanilla. “The plant is no longer producing soybeans for the farmer, it’s producing nematodes.”

She encourages proper management and testing to avoid devastating results to your crop. She credits farmers planting resistant varieties as a way to combat SCN.

“More than 90 percent of the soybeans that are grown in Michigan are resistant to soybean cyst nematode,” said Quintanilla. “Unfortunately, SCN is developing resistance to this resistance.”

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