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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Publications at this Location » Publication #419838
Research Project: Resilience of Integrated Weed Management Systems in Midwest Crop Production Systems

Location: Global Change and Photosynthesis Research

Title: Soybean (Glycine max L.) canopy response to simulated dicamba vapor drift using unmanned aerial sensing

Author
item KERR, DYLAN - University Of Illinois
item HAGER, AARON - University Of Illinois
item ALLEN, DYLAN - University Of Illinois
item LEAKEY, ANDREW D B - University Of Illinois
item BOWMAN, DENNIS - University Of Illinois
item Williams, Martin

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2025
Publication Date: 6/23/2025
Citation: Kerr, D., Hager, A., Allen, D., Leakey, A., Bowman, D., Williams, M. 2025. Soybean (Glycine max L.) canopy response to simulated dicamba vapor drift using unmanned aerial sensing. Pest Management Science. https://doi.org/10.1002/ps.8954.
DOI: https://doi.org/10.1002/ps.8954

Interpretive Summary: Sometimes applications of the herbicide dicamba can move off-target and injure sensitive vegetation, particularly soybean that is not engineered to tolerate the herbicide. We evaluated how reflectance of the sensitive soybean canopy changes with low-level exposure to dicamba. We were able to detect modest soybean injury from dicamba with sensors that measure specific regions of the electromagnetic spectrum. Sensors that measure the same spectral channels are mounted on space-based platforms, which may lead to methods quantifying the extent of dicamba off-target movement in the landscape.

Technical Abstract: BACKGROUND: Concerns about off-target dicamba exposure to sensitive vegetation have escalated following the commercialization of dicamba-tolerant (DT) soybean [Glycine max (L.) Merr.] and cotton (Gossypium hirsutum L.) The spectral response of plant injury at the field scale is a crucial knowledge gap that may help researchers understand dicamba's fate in the environment. Non-DT soybean (hereafter referred to as 'soybean') is the ideal sentinel crop due to extreme sensitivity to dicamba. Field experiments were conducted to characterize the multispectral signature associated with vapor drift injury in soybean from dicamba. The objective was to use remote sensing to determine the extent to which the visible portion of the electromagnetic spectrum relates to soybean canopy injury from simulated vapor drift of dicamba. RESULTS: At only 1/10,000th of a labeled use rate of dicamba, soybean injury was observed 8 days after treatment. Correlations between simulated vapor drift and changes in reflectance at the single spectral channel red-edge and vegetative indices excess red (ExR) and green leaf index (GLI) were observed. This study demonstrates the potential of single spectral channels for detecting off-target dicamba injury in soybean, with changes in reflectance following dicamba treatments observed at all channels. CONCLUSIONS: The ability to differentiate the spectral response between dicamba-injured and dicamba-tolerant soybean canopies from simulated dicamba vapor drift can be achieved using both single spectral channels and vegetative indices. These findings usher in the possibility that remote sensing satellites, which are well documented for identifying crop stress on the landscape, could be harnessed to understand the extent to which dicamba injury appears following over-the-top (OTT) application in DT soybean. Remote sensing technology could be instrumental in monitoring off-target herbicide injury and mitigating the effects of dicamba drift.