Soybean varieties that are resistant to the soybean cyst nematode are tremendously effective management tools. These resistant varieties produce greater yields and result in lower SCN numbers at the end of the season than nonresistant (susceptible) varieties. Thanks to the hard work of plant pathologists and soybean breeders, there are literally hundreds of SCN-resistant soybean varieties for Iowa growers to choose from. That's awesome. And overwhelming. How do you pick a good SCN-resistant soybean variety from the hundreds that are available? Gregy Tylka, an Iowa State University Extension plant pathologist and nematode expert, offers the following answer. There is some debate about how to select the best variety, says Tylka. Do you need to consider SCN reproduction data from the field as well as yield data? Should you look at single-site yield data from locations near you, yield data averaged from across the state, or yield data averaged across multiple years? And, should you consider yield data from small plots or large strip trials or both? To select high-yielding SCN-resistant soybean varieties that keep SCN numbers in check, Tylka says you should look for:
• Data from as many different reliable sources as possible, including university variety trials and company-sponsored strip trials.
• Data from experiments that measured SCN reproduction on the soybean varieties in the field as well as yield (high-yielding varieties don't necessarily control SCN numbers the best.)
• SCN-resistant varieties that yielded consistently well in numerous SCN-infested fields. Yield data from noninfested fields are not useful.
• SCN-resistant varieties that kept SCN population densities from increasing or that decreased numbers during the growing season
• Consistently high-yielding SCN-resistant varieties with resistance from various sources – i.e. PI 88788, Peking, Hartwig, etc.
"There's no way to ensure that you select the absolute best SCN-resistant soybean variety for your fields," he sums up. "But using the points listed here should help you select SCN-resistant varieties that allow soybeans to be grown profitably for many years to come."