In South Dakota soybean fields the soybean cyst nematode is the most damaging pest. A field day will be held at South Dakota State University Southeast Research Center in Beresford on Aug. 28 to help growers learn more about strategies to manage SCN and the soybean aphid.

"The soybean cyst nematodes are microscopic parasites that infect roots and rob plants nutrients leading to significant yield losses annually," said Emmanuel Byamukama, SDSU Extension Plant Pathology Specialist.

Byamukama said the challenge with managing soybean cyst nematode (SCN) is that SCN can infect soybean and cause significant yield loss without plants necessarily showing visual symptoms.

"This makes it difficult for growers to make management decisions when soybean plants look just as normal. Consequently, SCN populations in the soil can build up every season unchecked and reach levels that cause even greater yield losses," Byamukama said.

Another soybean pest that is of economic importance is the soybean aphid.

"Soybean aphids have piercing-sucking mouthparts that are used to siphon plant sap; visible damage is subtle or unapparent until plants are heavily infested, but yield can still be reduced before this point," said Kelley Tilmon, SDSU Soybean Entomologist.

Planned activities during the Aug. 28 field day include a SCN demo plot tour, hands-on identification of SCN, and sampling for SCN. Presentations on use of resistant soybean cultivars to manage SCN and aphids, and nematicide effectiveness will also be given. 

All activities start at 6:30 p.m. at the SDSU Southeast Agricultural Research Farm, Beresford. The farm is located at 29974 University Road, Beresford (six miles west of Beresford, SD on Highway 46 and three miles south on University Road).

For more information, visit or call (605) 688-4521.