Soybean Cyst Nematode Resistant Soybean Trial

Soybean cyst nematode (SCN) was identified in Iowa less than 30 years ago and is now recognized as a major pest of soybeans, particularly in sandy soil regions such as the Muscatine Island. Effective management has relied on crop rotation and the use of resistant varieties. Recently, some SCN resistant varieties have not been performing to expectations in certain fields. The reason for this is thought to be the repeated use of varieties obtaining their resistance from a single source, PI 88788, which has led to the development of SCN populations resistant to PI 88788. This project was initiated to help identify soybean varieties with different and effective sources of SCN resistance to provide management choices that will maintain soybean profitability

Evaluation of Soybean Varieties Resistant to Soybean Cyst Nematode

Use of resistant soybean varieties is a very effective strategy for managing soybean cyst nematode (SCN), and numerous SCN-resistant soybean varieties are available for Iowa soybean growers. Each year, public and private SCN-resistant soybean varieties are evaluated in SCN-infested fields in Iowa by Iowa State University personnel. The research described in this report was performed to assess the agronomic performance of SCNresistant soybean varieties and to determine the effects of the varieties on SCN numbers or population densities

Soybean cyst nematode: Challenges and opportunities for sustained, profitable soybean production

The soybean cyst nematode (SCN), Heterodera glycines, continues to be a widespread and damaging pathogen of soybean. The pest has been found in all soybean-producing states except New York and all Iowa counties except Allamakee (Figure 1). Although the nematode has been present in the Midwest for four decades, the situation with SCN continues to evolve

SCN-Resistant Soybean Variety Trial

Soybean cyst nematode (SCN) was first found in Iowa 30 years ago and it has quickly spread throughout the state and is a major threat to soybeans. SCN management involves growing non-host crops and SCN-resistant soybean varieties. There are hundreds of SCN-resistant varieties available, but almost all have PI 88788 as the source of resistance. Some SCN-resistant varieties have not performed well in certain fields, and SCN populations that can reproduce on PI 88788 may be developing due to frequent use of varieties with resistance from PI 88788. This research effort was designed to identify SCN-resistant varieties that will perform well in these problem areas and help manage SCN populations for long-term soybean profitability

Where do we stand with soybean cyst nematode, resistance, and seed treatments?

The soybean cyst nematode (SCN), Heterodera glycines, is a major yield-limiting factor of soybean in the United States and Canada (table 1). One thing contributing to the large amount of damage caused by SCN is its widespread distribution. The nematode has been found in every soybean-producing state in the United States except West Virginia and in all Iowa counties (figure 1) (Tylka and Marett 2017). And results of repeated random surveys of Iowa done in the 1990s (Workneh et al. 1999) and in the mid 2000s and in 2017 (Tylka unpublished) indicate SCN is present in 60% to 70% or more of the fields in Iowa

SCN females on roots signal infestations and possibly ineffectiveness of resistance

Many fields are not known to be infested with the soybean cyst nematode (SCN) because obvious, above-ground symptoms do not always occur. A reliable way to check for SCN on non-resistant (susceptible) soybean varieties is to dig roots, carefully crumble away much of the soil from the roots, and look for the adult SCN females. The females appear as small, round, white objects on the roots and are about the size of a period at the end of a sentence