Soybean cyst nematode sampling can take place anytime in any crop, but there is likely to be a higher and more detectable occurrence of SCN in the fall following a soybean crop.
Soybean cyst nematode is an all-too-common yield robber; in fact, its considered the most damaging soybean pathogen in North America with research showing that it can cause over 40% yield loss in some cases. This pest can quietly sneak up on growers as it causes yield loss with no obvious above-ground symptoms.
SCN poses a threat to many growers throughout South Dakota, as it has been positively confirmed in many counties. This nematode attacks the root of the soybean plant, which in turn can pose a greater risk for other fungal pathogens to easily infest the plant through open wounds. SCN tends to spread from field to field by equipment, erosion, wildlife, and other environmental factors. Once a field is infested with SCN, it is highly unlikely to eradicate it; however, reducing the population is possible.
If SCN is detected in a field, there are several integrated pest management practices that should be considered. Lengthening crop rotation (three crops or more) removes the host crop (soybean) for a longer period of time, which can help to decrease SCN populations. Other options include purchasing SCN-resistant soybean cultivars for any level of infestation and/or the use of nematicide seed treatments in heavy infestations (>10,000 eggs/100 cc of soil).
Soybean cyst nematode lives in the top 8 inches of the soil, so when testing, use a soil probe or spade to take at least 20 topsoil samples at an 8-inch depth in areas no larger than 15 to 20 acres. Field entrances, low lying areas, and fence lines are good areas to target. When sampling, angling the probe or spade into the soybean row is an ideal practice. Soil should be mixed well and placed in a soil sample bag.
South Dakota soybean growers can obtain SCN soil sample bags and SCN testing free of charge through the SDSU Plant Diagnostic Clinic, courtesy of the South Dakota Soybean Research and Promotion Council. To obtain SCN soil sample bags and submission form/instructions, call 605-688-5545 or 605-688-4521 or stop by a SDSU Extension Regional Office. The sample submission form can also be found at SDSU Plant Diagnostic Clinic website (go to sdstate.edu and search “SDSU Plant Diagnostic Clinic”). Sampling fields every two to three years can help monitor populations (or lack thereof) and help explain yield losses in question. For additional information on SCN and to better understand SCN test results, visit extension.sdstate.edu and search “SCN.”
As we get closer to winter, our programming changes gears and more winter meetings are planned. A heads up for a couple upcoming programs of interest.
Northern Plains Forage Association annual meeting and educational seminars. The Northern Plains Forage Association will host its annual meeting on Dec. 6 from noon to 5 p.m. at the Holiday Inn in Brandon. The program will provide growers and industry people with an opportunity to learn from regional experts and network with others in the forage industry. Topics include understanding feed tests, annual forages for livestock feed, farm transition, forage rye/double cropping, and capturing manure nutrients on growing crops. Speakers include experts such as Dan Putnam, Kevin Sedivec and Glen Arnold, as well as others. Visit extension.sdstate.edu/events to RSVP by Nov. 27.
“Managing Soil: Maximizing Profit” is a one-day meeting designed for growers in eastern/southeastern South Dakota with an interest in learning more about soil health.
This years program will be at the Wagner Movie Theater on Dec. 10.
The program will focus on improving soil health through reduced tillage, diverse rotations, managing for better soil microbiology, and incorporating cattle with annual forages.
Speakers include local farmers and Extension experts. Please RSVP at extension.sdstate.edu/events by Dec. 2 to sign up. Continuing education credits will be offered for certified crop advisers.
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