Site-Specific Root Knot Nematode Control in Soybeans
The Problem
Root knot nematodes are microscopic parasites that attack plants at their roots, resulting in swollen root nodules called “galls” that disrupt the flow of water and nutrients through the roots and bind up energy that would otherwise go towards plant growth. Root knot nematodes cause severe damage to crops and result in dramatic yield losses.
The Work
John C. Rupe, professor of plant pathology with the University of Arkansas System Division of Agriculture, obtained funding for a multidisciplinary research effort through the USDA’s Critical Agricultural Research and Extension program. As principal investigator, Rupe coordinated the efforts of plant pathologists, nematologists, soil scientists and agricultural economists in Arkansas, Louisiana, and Mississippi.
There are no high-yield soybean varieties naturally resistant to root knot nematodes, so researchers focused on testing nematicide soil applications and seed treatments. Previous research demonstrated that the pre-plant fumigant Telone II is the most effective of the available technologies. Application of Telone II is costly, so a primary component of the research was to investigate cost-efficient control strategies.
Root knot nematodes are more prevalent in coarse, sandy soils than dense soils and clays. Since soil structure can vary significantly within individual fields, researchers hypothesized that it might be possible to only apply treatments of Telone II in the areas most likely to have larger root knot nematode populations.
In test fields, soil structure was analyzed using electrical conductivity measurements. Using the resulting soil structure maps, researchers were able to selectively apply Telone II on the higher-risk nematode areas.
The Results
Through drone and satellite imagery and evaluation of crop yield data, researchers found that soil-texture-specific applications of Telone II offered good defense against root knot nematode infestation.
About the Researcher
John C. Rupe
- Professor of Plant Pathology
- B.S. in Plant Pathology from Colorado State University, M.S. in Plant Pathology from University of Kentucky, and Ph.D. in Plant Pathology from University of Kentucky.
- Rupe’s primary research focus is on the epidemiology and control of soybean diseases. In close collaboration with soybean breeders, Rupe has also played a role in the creation of numerous soybean cultivars, including ‘Ozark’ and ‘Osage.’