The soybean cyst nematode (SCN), Heterodera glycines, causes over $1 billion in revenue loss throughout the U.S.; and in South Dakota, the estimated revenue loss is over $4 million, considering a conservative two bushel loss per acre and considering 250,000 acres impacted and $8 per bushel. This makes SCN the most economically important soybean production constraint. SCN management is highly prolific, since each cyst can produce up to 300 eggs and the nematode can complete up to three reproductive cycles in one season under South Dakota conditions, making it difficult to eradicate from soil. Although SCN was first reported in South Dakota over 24 years ago, awareness and periodic sampling for SCN in South Dakota are still limited. A continued outreach program and sponsored SCN testing are therefore crucial in creation of SCN awareness and monitoring of SCN populations in soils.

Continue to offer sponsored SCN testing services to South Dakota producers.

We will continue to foster/create SCN awareness and to demonstrate effective SCN management practices. Producers and crop consultants will continue to submit SCN soil samples for free SCN testing. This incentive will encourage sample submission, and each sample’s results will be communicated to the submitter with recommendations for management, depending on the level of SCN found.

Currently, SCN has been detected in 32 counties, with Brule being the latest confirmed to have SCN. This indicates the widespread occurrence of SCN in major soybean-producing counties, and therefore requires continued effort to create awareness of SCN and the need to periodically test soil for SCN. With the recent floods in the eastern part of the state, it is possible that SCN-infested soil may have been moved around to different locations, and therefore a need for continued testing of soil for SCN. Soil testing for SCN can reveal presence of SCN in new locales, and also note SCN population changes. Increasing SCN populations in previously positive fields would necessitate a change in management strategies, such as switching between sources of SCN resistance or using nematicide seed treatments.

Growers test their soils for SCN and receive information on management strategies specific to their fields.

Updated January 20, 2021:
I. Statement of the project objective(s):
Continue to offer sponsored SCN testing services to SD producers.

II. Statement of quantifiable progress toward project objective(s) achieved during this reporting period:
In the first quarter, 153 soil samples were tested for SCN. These came from 12 counties. So far the majority of the samples are showing less than 3000 eggs/100 cc of soil. Complete results will be posted in the next quarter.

III. Activities planned between now and the next reporting period:
Continue to promote SCN testing via radio, social media, extension talks. This testing will be free to South Dakota producers, thanks to this grant.

Updated February 26, 2021:
I. Statement of the project objective(s):
Continue to offer sponsored SCN testing services to SD producers.
II. Statement of quantifiable progress toward project objective(s) achieved during this reporting period:
In the 2nd quarter, 263 soil samples were tested for SCN. The majority of the samples are showing less than 3,000 eggs/100 cc of soil.
III. Activities planned between now and the next reporting period:
The next quarter being the winter months, we dont expect soil samples to be submitted for SCN testing. We will continue to promote SCN testing via social media and extension talks.
IV. Problems and/or obstacles that may impact the completion date, cost or scope of the project:
The plant defense inducers component of this research proposal was not funded, therefore, no work is being done on this topic.

Updated July 30, 2021:
I. Statement of the project objective(s):
Continue to offer sponsored SCN testing services to SD producers (other objectives were not funded)
II. Statement of quantifiable progress toward project objective(s) achieved during this reporting period:
The 3rd quarter being winter months, no SCN samples came through the diagnostic clinic.
III. Activities planned between now and the next reporting period:
We will continue to promote SCN testing via social media and extension talks
IV. Problems and/or obstacles that may impact the completion date, cost or scope of the project:
The plant defense inducers component of this research proposal was not funded, therefore, no work is being done on this topic

Updated July 30, 2021:
I. Statement of the project objective(s):
Continue to offer sponsored SCN testing services to SD producers
II. Statement of quantifiable progress toward project objective(s) achieved during this reporting period:
We continued to create soybean cyst nematode awareness among growers, crop consultants and agronomists through webinars, field days, pesticide trainings, and social media especially twitter. Stakeholders were encouraged to sample their soil and send it in for SCN testing especially this year due to drought conditions which tend to make SCN worse. Emphasis was also placed on the awareness of one source of SCN resistance PI88788 failing to provide protection against some SCN populations and hence the need to rotate between sources of SCN resistance. A total of 416 soil samples were submitted and tested for SCN from July 1 2020 through June 30, 2021. The majority of these samples were negative for SCN or had less than 500 eggs/100 cc of soil. Each soil test report was accompanied with management recommendations, depending on the level of SCN in the soil.
III. Activities planned between now and the next reporting period:
None
IV. Problems and/or obstacles that may impact the completion date, cost or scope of the project:
None

Soybean producers in South Dakota will be afforded the opportunity to submit soil samples for free SCN testing of their fields. This will allow producers to determine if they have SCN infestations, giving them the chance to implement management strategies to limit damage and control SCN on their fields.