Skip to main content

2018 Field Plot Summaries for Soybeans: Plant Disease and Fungicide Trials

Written collaboratively by Dalitso Yabwalo, Connie Tande, and Emmanuel Byamukama


This is a summary of soybean field research studies that were conducted in 2018. The purpose of these studies was to assess efficacies of fungicides for foliar disease management and nematicides/seed treatment products for nematode management. The studies were conducted on growers’ land in Brookings and Volga Research Farm.

Fungicide and nematicide products used in these trials were approved for use in the state of South Dakota although in some instances experimental products were used within the restricted use guidelines. Some of the protocols exercised in these experiments include changes in rate and application timing and should not be taken as recommendations. Therefore, producers should always read and follow product label application protocols such as product use, application method, safety handling, pre-harvest, re-entry intervals and all other safety guidelines.

In general, foliar disease pressure was low at the Volga location. As a result, there were no statistically significant differences among treatments, although some products had numerically higher yield. Overall, fungicide treated plots had on average 3 bu/A increase in yield. For SCN, there were no significant differences among treatments, but the susceptible non-treated check had significantly low yield, indicating that nematicide seed treatments prevented yield loss for the SCN susceptible cultivar but not for the resistant cultivar.


We acknowledge financial contributions from the SD Soybean Research and Promotion Council, SDSU Agricultural Experiment Station and collaborators from private industry. On-farm research host Dave Mack (Brooking, SD) and the grower Rick Kerr are acknowledgement.