When it comes to integrated disease management, experts have always considered corn a non-host for diseases like sudden death syndrome (SDS) in soybeans.
But that perception is changing says OMAFRA field pathologist Albert Tenuta. In this episode of RealAgriculture Soybean School, Tenuta says there is growing evidence that corn residue can harbour or allow the SDS fungus to grow and sustain itself.
“What we’ve started to see is residue such as cobs and kernels, and soybean roots that are left in the ground can harbour the SDS fungus,” explains Tenuta. The fungus can then have an impact on the next soybean crop when it comes around again in the rotation.
SDS is typically identified by interveinal chlorosis and necrosis of the upper leaves. SDS in soybeans results in average yield loss of about 20 percent and can reach up to 60 percent.
So how do farmers make sure they’re not creating an invitation for SDS and other yield-robbing diseases to set up shop in their fields? Tenuta says extending rotations is a simple solution to the problem. By adding wheat, growers will likely see less SDS than in corn-soy rotations.
See Related: Genetics Lead Fight Against Sudden Death Syndrome
Tenuta also advises farmers to pay attention to the amount of corn residue they leave on their fields. “From a pathology and disease management side of things, minimizing that residue could definitely decrease your disease risk,” he says. But you don’t have to get rid of all the trash. By maintaining 25 to 30 percent residue, Tenuta believes farmers can get the soil health benefits crop residues deliver while also reducing disease risk.
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