Drought conditions lead to increased soybean cyst nematode reproduction

News

Drought conditions lead to increased soybean cyst nematode reproduction

An extension nematologist says for reasons unknown dryness leads to higher soybean cyst nematode pressure.

Greg Tylka with Iowa State University tells Brownfield that’s bad news for farmers impacted by the drought.

“Every time drought conditions develop, for some reason that we haven’t out, reproduction is increased. So in a normal year where we might end up with a final egg count of 5,000 eggs per half-a-cup of soil, in a drought year that would be 10 or 15,000 eggs per half-a-cup of soil.”

He says more eggs means more potential for crop damage in future years, beginning with acres rotated back to soybeans in 2023.

“The good news is when those fields are rotated to corn in 2022, the egg counts will drop because (during) a year of corn a lot of the eggs hatch out and the little worms starve if they hatch out in a year that corn is being grown. But the problem is they don’t all hatch out.”

Tylka says at most 40 to 50 percent hatch out, and he advises adding another year of corn to help mitigate SCN if egg counts are above 12,000 per half-cup of soil.

.