Northern Research and Demonstration Farm
The primary method of managing yield loss due to the soybean cyst nematode (SCN) is through the use of resistant soybean varieties. Most SCN-resistant varieties available in Iowa have the PI 88788 source of SCN resistance. There are concerns that over time, SCN will be able to overcome the PI 88788 resistance. Small plots (two or four rows wide and up to 20 ft long) often are used to evaluate yields and nematode control of SCN-resistant soybean varieties. Yield results are more variable in small plots than in larger strip plots, but data from soil samples in small plots more accurately represent SCN population densities from the areas in which yield data are being collected.
Iowa State University
Tylka, Gregory L. and Marett, Christopher C., "Comparing Yields of Soybean Varieties with Different Sources of SCN Resistance in Strip Trials" (2010). Iowa State Research Farm Progress Reports. 404.