Ankeny, Iowa, USA
August 6, 2010

Sudden Death Syndrome (SDS) is disease of major concern for soybean growers due to its ability to significantly reduce yields. “Depending on the soybean variety, it can cause slight to 100 percent yield loss, and it is one of the top four yield-robbing soybean diseases,” says David Wright, director of contract research and strategic initiatives for the Iowa Soybean Association (ISA.)
Iowa State University Extension Field Agronomist Mark Licht says growers are starting to see signs of SDS in their fields this growing season.

“We started seeing SDS show up in central and west central Iowa. Early in the week, it was fairly mild and at the end of the week, we were seeing places in the field that were quite severely affected. We loss the yellowing [of the leaves] and went straight into dropping of the leaves and seeing the death that occurs from that.”

The disease is spreading more than most expected; SDS has shown up in eastern and northern Iowa, Illinois and Minnesota. It’s developing in areas it has not been in the past, and Licht says weather is a major factor.

“SDS is typically found when we have periods when it’s really wet, especially if it’s cool and wet shortly after planting. In Iowa, we have been really wet ever since that cool period we had in early May. For us to see it in the lower, wetter areas where we have compacted soils should be of no surprise because we have had conditions nearly perfect for SDS to show up.”

Fungicides do not help with SDS so there’s not a lot growers can do this season. Licht advises to think ahead to the next year by start scouting now.

“It is good to take note of the areas in the field that are more severely affected, and take note of the soybean varieties that are planted out there and how they are responding—how tolerant or susceptible they are to the pathogen,” Licht says. “Keeping an eye on these two things is good because when we start planting for the 2011 season, we’ll know we should target certain soybean varieties that are known to have a higher tolerance. Additionally, fields that are more severely affected can be planted a little later when the conditions for SDS infection are less risky.”

Licht urges growers to watch their fields for SDS and then begin a dialogue with extension specialists and seed agronomists to get a plan in place for the next year.

To hear this podcast and others, go to ISA’s Production Research website, www.iasoybeans.com/productionresearch/productionvideo.html.

To learn more about ISA, visit its website at www.iasoybeans.com.

The Iowa Soybean Association develops policies and programs that help farmers expand profit opportunities while promoting environmentally sensitive production using the soybean checkoff and other resources. The Association is governed by an elected volunteer board of 21 farmers.

Website: http://www.iasoybeans.com

Published: August 6, 2010