Database Research Summaries
2018 Dicamba Effect in Soybean Seed

calendar_today Year of Research: 2018
update Posted On: 12/05/2019
group Kirk Howatt (Principal Investigator, North Dakota State University)
bookmark North Dakota Soybean Council

Research Focus

The focus of this project is to determine the concentration of dicamba and the characteristics of soybean progeny when developed under dicamba exposure.


  • Quantify the dicamba concentration of the seed because it will be an important measurement to understand legal implications.
  • Provide a diagnostic tool to assess damaged seed lots.


  1. Most round-up ready soybean cultivars reported SCN resistance and were confirmed in the greenhouse test. The conventional soybeans also contained some breeding lines being
  2. Soybean in the field expressed mild to severe leaf cupping and apical meristem damage depending on the proximity to dicamba application and whether the plants were covered by tarp.
  3. Although treatment effect resulted in wide variance when comparing most areas, symptom expression was associated with fewer yields. Weight of 200 seeds was less from around treated areas because less seed was retained above an 18/64 screen but more was retained between the 12/64 and 15/64 sizes.
  4. Weight per seed was similar between treatments within a size category, which indicated density of the seed was not affected. Oil content tended to be greater in seed from around treated plots but protein was very similar and variable in rank between the two at each location.
  5. Germination tended to be less and hard seed more prevalent for seed from near treated plots, although differences were not identified. Germination within seed size was generally variable for treatment rank.  Height and growth stage of progeny grown in the greenhouse was very similar within size category.


  • This research provides valuable information on how to preserve the quality of North Dakota soybean.
  • This work pertains to the seed industry because viability of seed lots could be substantially affected. Demonstrating a separation method to remove damaged seeds will preserve the integrity of the seed industry.

For more information about this research project, please visit the National Soybean Checkoff Research Database.

Funded in part by the soybean checkoff.