Figure 1. Side-by-side comparison of 2,4-D and dicamba symptoms from a Pioneer soybean herbicide response demonstration. Plants exposed to 2,4-D display leaf strapping, with the veins pulled into a more parallel orientation, while leaves exposed to dicamba show more of an upward cupping/drawstring effect.
Figure 2. Soybean plants showing upward leaf cupping characteristic of dicamba injury. Symptoms are limited to newer growth, with older leaves unaffected.
Figure 3. Soybean plants in a field near Waterville, KS showing symptoms of exposure to a low dose of dicamba. Left: Plants showing leaf crinkling, upward leaf cupping, and whitish leaf margins on new growth characteristic of dicamba injury. Right: Symptoms of a very low dose of dicamba exposure, including crinkling at the leaf tips and slight downward cupping.
Figure 4. Soybean trifoliate showing symptoms of 2,4-D injury. Leaflets are strapped, with parallel venation.
Figure 5. Soybean injury after foliar application of a PPO herbicide. Leaves show some degree of distortion and midrib shortening, which could be mistaken for other types of injury, but also show burning of leaves exposed at the time of application characteristic of PPO damage
Figure 6. Soybean plants showing characteristic symptoms of Group 15 herbicide injury. The midribs are shortened, resulting in heart-shaped leaflets.
Figure 7. Curling and stippling of soybean leaves caused by spider mites
Figure 8. Curling of soybean leaves caused by potato leaf hopper feeding.
Figure 9. Soybeans with leaves folded in and flipped over in response to drought stress.
Anderson, M., and R. Hartzler. 2020. Identifying Common Herbicide Symptoms in Soybean. Integrated Crop Management. Iowa State University Extension. https://crops.extension.iastate.edu/blog/bob-hartzler-meaghan-anderson/identifying-common-herbicide-symptoms-soybean
Gonsolus, J. 2018. Symptoms of Dicamba Exposure in Soybean. University of Minnesota Extension. https://extension.umn.edu/herbicides/symptoms-dicamba-exposure-soybean#postemergence-applications-of-soil-residual-herbicides-1037961
Hager, A. 2019. What Causes Cupped Leaves Other than Dicamba? Successful Farming. https://www.agriculture.com/crops/pesticides/what-causes-cupped-leaves-other-than-dicamba
Hager, A., and C. Sprague. 2000. Soybean Leaf Cupping/Puckering. The Bulletin. University of Illinois Extension http://bulletin.ipm.illinois.edu/pastpest/articles/200013f.html
Hartzler, R., and M. Anderson. 2018. Crop Injury Associated with Growth Regulator Herbicides. Integrated Crop Management. Iowa State University Extension. https://crops.extension.iastate.edu/cropnews/2018/07/crop-injury-associated-growth-regulator-herbicides
Osipitan, O.A., J. Scott, and S. Knezevic. 2019. Effects of Dicamba Micro-Rates on Yields of Non-Dicamba Soybeans. Crop Watch. University of Nebraska-Lincoln. https://cropwatch.unl.edu/2019/effects-dicamba-micro-rates-yields-non-dicamba-soybeans
Werle, R., R. Proost, C. Boerboom. 2018. Soybean Injury From Dicamba. A4161. University of Wisconsin Extension. https://ipcm.wisc.edu/download/pubsPM/DicambaInjurySoybean_A4161.pdf
Zimmer, M., C. Hayden, F. Whitford, B. Young, and W. Johnson. 2019. Differentiating 2,4-D and Dicamba Injury on Soybeans. WS-56/PPP-126. Purdue University Extension. https://ag.purdue.edu/btny/purdueweedscience/wp-content/uploads/2021/01/WS-56.pdf