SCN Rides On Waves In Flooded Fields

01:19PM Sep 17, 2019
SCN in flooded fields
SCN Rides On Waves In Flooded Fields
( Photos: Sonja Begemann and Stefano Sacchi )

Flooding this past spring won’t just affect fields and productivity in 2019 — the impact will linger for years to come. In addition to addressing compaction and weeds, you need to be mindful of possible soybean cyst nematodes (SCN).

It’s more important than ever to test fields for SCN this year.

“With early season flooding, before seed was even in the ground, how did the soil move?” asks Kaitlyn Bissonnette, University of Missouri Extension professor and director of SCN Diagnostics. “Where did that soil deposit? That matters because the soil could contain cysts that float and move with flooded soils.”

Cysts Don’t Drown

According to research from the University of Arkansas, SCN juveniles can survive in water up to 630 days and possibly longer. In flooded soil, they can survive seven to 19 months depending on soil type. Additionally, SCN eggs can survive through dormancy for years even without soybeans.

“They absorb oxygen through their body wall or cuticle, which is made almost exclusively of proteins (and no chitin),” says Greg Tylka, Iowa State University nematologist and leader of the SCN Coalition. “Waterlogged soils might have greatly reduced levels of oxygen. But many plant-parasitic nematodes, including SCN, can survive for long periods of time with very little oxygen.

“Typically, the eggs are more tolerant of environmental stresses than hatched juveniles,” Tylka explains. “So, it’s likely that SCN eggs in infested fields are not adversely affected by waterlogged soils either.”

GMO Solution On The Way

”BASF is developing a trait that would provide tolerance against cyst nematode in soybeans and protect yields,” says Marc Hoobler, BASF soybean agronomy lead. The company is also testing it against other nematode species.

For more information about where and how to sample for SCN, and where to send samples, visit