Yield Improvement and Stability for Soybean Cultivars with Resistance to Heterodera Glycines Ichinohe

Cultivar selection is the most important management decision soybean Glycine max (L.) Merr. producers can make to achieve high yield. This experiment was conducted to evaluate the contributions to genetic gain and yield stability made by cultivar resistance to soybean cyst nematode ( Heterodera glycines Ichinohe, SCN). Studies were established at three locations in Iowa during 2005 and 2006 in fields where SCN population densities ranged from 100 to 12,500 eggs 100‐cm −3 soil of various Hg‐Types. Twenty‐three cultivars that varied by year of release and resistance to SCN were evaluated. Yield variability among environments was less for new SCN‐resistant cultivars. Genetic gain was 14.9 kg ha −1 yr −1 greater for SCN‐resistant cultivars compared with SCN‐susceptible cultivars. Estimated genetic gain was similar for both high and low‐yielding environments. Yield potential was greater for new cultivars but yield stability was similar to old cultivars. There was no evidence of a negative relationship between yield and yield stability. Cultivars resistant to SCN had greater yields in both high‐ and low‐yielding environments and provided greater yield stability. These data support the selection of new cultivars that yield well at multiple locations and specifically cultivars with resistance to SCN for fields infested with SCN as a method to increase yield and yield stability.