By Nufarm

While harvest will be shortly underway, it is never too early to start your preparation for next season. Implementing a late season nematode sampling program is a very important practice to know your nematode levels for both next year's corn and soybean crops.  The guidelines below illustrate what you will know about your in-field yield robbing nematode pressure.

Soybean Cyst Nematode (SCN) is considered one of the most damaging pathogens on soybeans in the Midwest and the United States. SCN has a unique biology that allows it to cause great yield loss (greater than 50 percent), to reproduce very quickly and to survive 10 years or more in the absence of a host crop. Utilizing a proactive approach to the 2023 growing season by sampling for SCN this fall will provide the field knowledge you need to make the most beneficial protective seed treatment decisions

Fall is the ideal time to sample fields for presence and population densities of SCN.  Specific reasons to sample fields include:

1. Discover if SCN is present before growing soybeans in 2023
2. Determine if SCN is responsible for lower-than-expected soybean yields in 2022. Review Yield maps for areas showing below normal Average Production History (APH).
3. Monitor SCN population densities after growing SCN-resistant soybean varieties

General guidelines for fall sampling for SCN

• Collect samples from harvested corn fields to determine if SCN is present to have a level of a known population of SCN prior to planting soybeans in 2023.
• Collect soil cores from under the old crop rows if soybeans were grown this season.
• If grid sampling, collect one or two extra soil cores from every grid cell sample and combine these extra cores from the number of cells that represent approximately 20 acres.
• If sampling conventionally (not grid sampling), collect 15 to 20 soil cores in a zigzag pattern from no more than 20 acres (ideally 1 sample per acre). The 20-acre sampling areas do not need to be square or rectangular; samples can be collected from zones according to the agronomic features of the field.
• In fields where SCN has not been discovered, high-risk areas where SCN may be first found include high pH spots, low spots, near fence lines, and other places where soil from other fields may have been introduced, for example, changing field borders or extensive field work.
• Soil cores should be a total depth of 8 inches.
• Trunemco seed treatment can be applied to the soybean seed as early as 12 months prior to planting with initial treatment mix.

Pertaining to corn, live nematode pressure identification and population can be sampled between the V6 and R3 stage.

• Use a soil probe collect cores at least 12 inches long.
• Collect a minimum of 5 cores per acre.
• Be sure and collect cores from root zone of plants showing stress for example, stunting or lack of nitrogen yellowing.
• Keep soil samples cool and in a sealed bag as to not dry out the soil samples. Ship in an insulated container directly to a lab of choice
• Trunemco corn seed treatment can be applied to the seed up to 12 months prior to planting in combination with corn seed treatments.

Trunemco Nematode Management is a seed applied technology with excellent levels of protection against the rising levels of nematodes in soybeans, corn, and cotton, controlling 14 different species of nematodes across the three crop labels.

In soybeans, Trunemco works in combination with all the base level seed treatment combinations.  It activates natural enzymes in soybean plant to provide a high level of protection as soon as the plant germinates. Trunemco has a second component colonizing around the newly established root providing nematode protection to the plant when nematodes cause the greatest plant damage, early in the life cycle of the plant.  Along with this protection Trunemco has been shown to increase plant vigor, helping plants stay one growth stage ahead, and allowing for higher yields at the end of the season.  The season ahead is providing a perfect opportunity to invest in a technology tool to help increase the yield potential of soybeans and corn that will be planted this upcoming spring.  Please consult your seed supplier now on how to source Trunemco treated seed.

We can expect to see the rise in SCN continue, but by taking both hard-wired resistance and layering additional seed treatment protection, growers are able to maximize their genetic potential. As the dollar per bushel goes up, the economic threshold is lowered; therefore, we’ve found the ROI of the additional on-seed nematode protection can be in excess of 3:1 in high-