SDS and SCN Yield Effect & Interaction by Soybean Variety


  • Examine performance of Pioneer® brand soybean varieties with differing levels of resistance to soybean cyst nematode (SCN) and sudden death syndrome (SDS).
  • Determine yield effect and interaction between SDS and SCN in Michigan.
  • Examine SCN reproduction on varieties with different SCN resistance sources.
  • Determine distribution and effect of SDS in Michigan.
Photo: Differences in SDS severity between Pioneer® brand variety 92M82 (left) vs. 92Y53 (right) on Aug. 17, 2012, near Decatur, MI.

Differences in SDS severity between Pioneer® brand variety 92M82 (RR) (left) vs. 92Y53 (RR) (right) on Aug. 17, 2012, near Decatur, Mich.

Study Description

  • The trial was established under center pivot irrigation on sandy soil with an average of 8,000 SCN eggs/100 cc soil, of HG type 2.5.7.
  • The trial was organized in a RCBD with 5 replicates. Each plot was 40 ft long, trimmed to 34 ft for harvest. Plots contained 6 rows in 15-inch spacing, with the center 4 used for rating and harvest.
  • The trial was located near Decatur, Mich., on ground that had been used for soybean trials in 2011.
  • SDS symptoms were rated using the standard university rating system of disease incidence (DI) on a 0-100% scale and a 1-9 disease severity (DS) scale to derive the disease severity index (DSI), where DSI = (DS/9) x DI
Photo: SCN - soybean roots


  • 92Y53 outyielded all other varieties and had no detectable foliar SDS symptoms.
  • Stand establishment of 92Y53 and 92M82 was significantly lower than that of 92Y51 and 92Y91, though this did not correlate with yield.
  • Final SCN numbers are currently being counted to determine SCN reproduction.
  • In a similar trial in 2011, there was a 17-fold increase in SCN population on 92Y51 and more than a 40-fold increase with 92Y91 and 92M82. No increase of SCN was noted on 92Y53; however, the population did not significantly decrease.
  • SDS was confirmed in Eaton county, bringing the total number of Michigan counties with confirmed SDS to 22.
  • Despite the relatively dry conditions, severe SDS symptoms were observed in scattered fields across the state, including this trial site.
Variety SCN/SDS Yield Bu/A DSI (Aug-17) Population/A
92Y53 (RR) PI548402/6 44.3 a 0.0 a 124,507 b
92Y51 (RR) PI88788/6 31.0 b 9.8 a 155,908 a
92Y91 (RR) - /5 12.7 c 50.9 b 159,924 a
92M82 (RR) - /3 5.8 d 76.3 c 134,000 b
LSD - 4.9 12.9 21,236
Map: SDS Confirmation - Michigan
Photo: SDS - soybean leaf

Research conducted by Martin Chilvers, Ph.D., Michigan State University as a part of the Pioneer Crop Management Research Awards (CMRA) Program. This program provides funds for agronomic and precision farming studies by university and USDA cooperators throughout North America. The awards extend for up to 4 years and address crop management information needs of Pioneer agronomists, sales professionals and customers.

PIONEER® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents. 2012 data are based on average of all comparisons made in 1 location through Nov. 2, 2012. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary.

Glyphosate Tolerant

R - Contains the Glyphosate Tolerant trait. Always follow grain marketing, stewardship practices and pesticide label directions. Varieties with the Glyphosate Tolerant trait (including those designated by the letter “R” in the product number) contain genes that confer tolerance to glyphosate herbicides. Glyphosate herbicides will kill crops that are not tolerant to glyphosate.