Profitable soybean yields can be produced in fields infested with the soybean cyst nematode (SCN) by growing SCN-resistant soybean varieties. SCN-resistant soybeans can keep SCN population densities from increasing and produce high yields.
Each year, Iowa State University compiles a list of SCN-resistant soybean varieties that are available to Iowa soybean farmers for the upcoming growing season. The list is published with support from the Iowa Soybean Association. The updated version of the publication, titled "Soybean cyst nematode-resistant soybean varieties for Iowa," is now available for use in planning the 2013 soybean crop.
Slightly fewer varieties for 2013, almost all with PI 88788 SCN resistance
The publication contains information about 155 SCN-resistant soybean varieties in maturity groups 0 and 1, 325 varieties in group 2 and 291 varieties in group 3. Only 15 of the 771 varieties, or 2 percent, have resistance from a source other than the common PI 88788 breeding line. There are 34 fewer varieties (see Figure 1) and two fewer companies represented in the list compared to last year's list.
Most of the varieties in the list are glyphosate resistant. Some have LibertyLink® herbicide resistance. And 63 varieties, or 8 percent, are neither glyphosate resistant nor LibertyLink®.
Figure 1. Number of SCN-resistant soybean varieties available to Iowa soybean growers from 1991 to 2012. The red portion of each bar represents the number of varieties with SCN resistance from a source other than PI 88788.
Many ISU varieties in the list
There are 21 SCN-resistant soybean varieties in the publication that were developed by Iowa State University scientists with soybean checkoff funding from the Iowa Soybean Association. Of particular note is variety "IAR3001 Phyto SCN," which has SCN resistance from PI438489B and PI90363; this is the only maturity group 3 soybean variety in the list with SCN resistance from a source other than PI 88788.
Publication available online and in print
The list of SCN-resistant soybean varieties for 2013 is available in PDF format online at the Iowa Soybean Association Production Research web site. Print copies of the publication will be available for purchase from the ISU Extension Online Store (PM 1649) by the end of October.
Greg Tylka is a professor with extension and research responsibilities in management of plant-parasitic nematode in the Department of Plant Pathology and Microbiology at Iowa State University. He can be reached at firstname.lastname@example.org or 515-294-3021.
• ISU's annual list of SCN-resistant soybean varieties for Iowa has just been released.
• Resistant soybean varieties can keep SCN numbers in check and produce high yields in SCN-infested fields.
• There are more than 770 varieties to pick from for Iowa in 2013.
• Most of the varieties for 2013 have the common PI 88788 source of SCN resistance.