Database Research Summaries2018 Non-Xtend Soybean Response to Simulated Dicamba Drift
Research Focus
The focus of this project is to provide additional data on the susceptibility of non-Xtend soybeans to different dicamba rates, timings, number of exposures, soybean trait, and environmental conditions.
Objectives
- Determine non-Xtend soybean injury and yield loss from dicamba exposure at different growth stages, rates, and multiple exposures.
- Determine injury and yield loss from dicamba exposure on different non-Xtend soybeans traits.
Results
- Soybeans treated with dicamba at the V3 stage expressed early season leaf cupping, but seemed to have recovered fairly well by 8 weeks after treatment, regardless of the application rate.
- Symptoms from the R1 and R3 applications were more persistent and evident through the remainder of the growing season. The most severe soybean injury occurred with the multiple application timings and at the highest rates.
- Soybean harvest was delayed and complicated due to unusually wet conditions in the fall. Soybean yield reduction from dicamba injury was not as great as visual injury ratings. Soybean yield loss was minimal from exposure during the V3 stage, regardless of exposure rate, or from the 1/1000X exposure rate, regardless of exposure stage or with multiple exposure timings. The greatest yield loss was from multiple exposure events and at the highest exposure rate of 1/100X dicamba.
- Visual soybean injury varied among varieties and timings. Soybean injury was higher from exposure at the R1 than the V3 stage of growth, similar to the other experiment. Visual injury from dicamba tended to be highest on the Stine 40BA02 variety and lowest on the Credenz 4746 LL variety. Lower injury on the Credenz 4746 variety may have been partially due to the longer maturity, but application on the same dates.
- Grain harvested from both experiments had extremely poor quality due to early season drought stress and delayed harvest as a result of excess moisture in the fall at harvest time. Consequently, seed viability was very low, highly variable, and not different among treatments.
Importance
This research will help provide new information and a better understanding of the factors affecting dicamba injury to non-Xtend soybeans to help guide management decisions in the future.
For more information about this research project, please visit the National Soybean Checkoff Research Database.
Funded in part by the soybean checkoff.
