Soybean cyst nematode (SCN) remains the number one pest in soybean production in the U.S. Per the 2023 Crop Protection Network review, SCN was responsible for 87 million bushels of yield loss. Today, both public and private researchers and labs have identified SCN in nearly all major soybean-growing areas in the U.S.

Photo submitted by Beck's Hybrids

SCN Map Source: https://www.plantpath.iastate.edu/news/scn-continues-spread-us-and-canada

SCN-resistant germplasm sources have been identified, developed, and incorporated into soybean breeding programs across the industry. These resistance sources are derived from soybean plant introduction (PI) lines with unique resistance gene combinations. Today, most new soybean variety releases contain some form of SCN resistance. There are several sources of genetic SCN resistance, but the PI 88788 source is the most widely adopted.

Over time, SCN populations have evolved tolerances to several sources of resistance in many geographies. SCN populations in these fields can now reproduce on soybean varieties with one or more resistance sources. Currently, most SCN-resistant varieties contain resistance from PI 88788, some with Peking (PI 548042), and fewer still are PI 89772.

In the last decade, Peking (PI 548042) has become a popular source of genetic resistance that remains very effective in PI 88788-tolerant populations. The Peking source of genetic resistance has demonstrated a reduction in SCN's ability to set up feeding sites and reproduce. Reducing reproduction is critical to long-term population management.

FUTURE OPTIONS

Researchers recently discovered a novel way to prevent SCN from attacking soybeans. The loss of function of the GmSNAP02 gene in resistant soybean varieties like PI 90763 and PI 437654 thwarts the ability of SCN to attack the soybean plant.

The next step in SCN management will be integrating the GmSNAP02 gene mechanism into varieties available to the plant.

SCN MANAGEMENT

Left unmanaged, SCN populations lead to a steady increase in yield loss. Reducing population densities once they have reached highly damaging levels is difficult. Scouting fields for the presence of SCN and sampling fields for nematode population densities are important management tactics.

Scouting fields for foliar plant symptomology and SCN egg cysts on roots (Figure 1) and soil sampling for SCN eggs are two critical management tools to define potential SCN populations when determining a cropping sequence and a rotation of SCN-resistant sources.

Photo submitted by Beck's Hybrids

In the cropping sequence, using non-host crops, non-host cover crops, and diligent weed control are essential "must-do" cultural tools. Growing soybean varieties with resistance to SCN, rotating SCN sources of in-plant resistance, and using nematode-protectant seed treatments are critical steps toward reducing SCN populations.

In 2025, Saltro® seed treatment will be added to Beck's Escalate^® yield enhancement system as an upgrade option to their base treatment containing Nemasect®. Nemasect alone has a 3.0 Bu./A. advantage in moderate to high soybean cyst nematode (SCN) infections.^*

Saltro Benefits:

SOIL SAMPLING FOR SCN

Soil sampling is the most important step for all soybean growers looking to define their SCN populations in fields that are or will be planted with soybeans. Although these soil samples can be pulled at almost any time (not frozen), the most representative data will be pulled from a fall or post-R6 (full bean in the pod) sample. For growers conducting annual or system soil sampling for nutrients, the soil samples can be split for nutrients and SCN testing.

Growers have an ally and resource at The SCN Coalition, a public/checkoff/private partnership formed to increase the number of farmers actively managing SCN. Their goal is to help soybean farmers increase their yields and profit potential. Beck's elite team of agronomists are also available to help growers manage SCN in their fields.

_{*8-year test results (2016-2023) from 303 trial sites}

_{Beck's - Farmers At Heart® - revolutionized the customer seed buying experience by remaining true to a foundation built on faith, family, and farming. Founded in 1937, Beck's appreciates the farmers who have helped them become the largest family-owned retail seed company and the third-largest seed brand in the United States. The Beck family is now in its fifth generation of family members who work in the business to honor God and help farmers succeed. The Beck family and team of employees help farmers achieve success from generation to generation through authentic customer experiences, product diversity, seed quality, and performance. With a home office located in Atlanta, Ind., Beck's serves farmers throughout the Midwest and Mid-South. For more information about Beck's Superior Hybrids, Inc., visit www.beckshybrids.com.}