INDIANAPOLIS — The Carolinas’ wet 2018 growing season presented tobacco and sweet potato growers with many challenges. Among those was achieving control of a relatively new species of root-knot nematode, Meloidogyne enterolobii.
“Meloidogyne enterolobii is considered a highly aggressive species,” said Lindsey Thiessen, Plant Pathologist at North Carolina State University. “It is very successful at causing infection with high rates of infection on the roots of host plants and causes more severe galling on host plants than other nematodes.”
The nematode, M. enterolobii, was identified in Florida more than a decade ago and was documented in North Carolina in 2011. Its presence has also been positively identified in South Carolina and Louisiana. M. enterolobii is a root-knot nematode, but it is a distinct species from the southern root-knot nematode, Javanese root-knot and peanut root-knot species that generally infect specific hosts in the southern United States.
More aggressive than other species, M. enterolobii has a wide host range, spreads rapidly and swiftly reproduces. There are currently no resistance traits available in commercially grown crops, including tobacco and sweet potato. It also breaks down any available resistance to other nematode species.
Yield losses from M. enterolobii can be substantial, and the especially damaging nematode species pulls nutrients away from tobacco foliage, causing wilting and reductions in harvest quality.
Even after fumigation, populations of this nematode are quick to return to previous levels. M. enterolobii overcomes all known root-knot nematode resistance genes. Currently, grapefruit, sour orange, garlic and peanut are considered non-hosts.
In 2017, Thiessen’s research showed the best treatments for M. enterolobii in tobacco were Telone® II soil fumigant, Telone II plus chloropicrin, or Telone II followed by another chemistry. In each trial, Telone II was applied as a drench treatment or a transplant water application.
While the untreated control plot experienced 53 percent root galling, root galling in the plot treated with Telone II was significantly reduced. According to the study’s results, plots receiving Telone® II soil fumigant experienced 26 percent galling, Telone® II plus chloropicrin had 17 percent galling, and Telone II followed by an insecticide/nematicide had 13 percent root galling.
“It’s imperative to achieve control to minimize economic damage to both tobacco and sweet potato growers,” Thiessen said.
To optimize fumigant activity, Thiessen recommends preplant soil be in working condition with adequate soil moisture, not hard-panned, and with optimum soil temperatures of 40 to 85 F.
Researchers, including Thiessen, are excited about the potential control offered by an experimental contact nematicide produced by Corteva Agriscience™, Agriculture Division of DowDuPont. The nematicide is currently included in university nematode control studies as Q8U80. This experimental product, which contains the active ingredient, fluazaindolizine, may give tobacco and sweet potato growers another tool in their battle against M. enterolobii and other yield-reducing nematodes.
“There is a need for more labeled chemistries to fight this nematode,” Thiessen says.
For more information about recently published research on this topic, visit: https://veggiepathology.wordpress.ncsu.edu/publications/demonstration-trials/.
Treating Meloidogyne enterolobii with Telone® II soil fumigant is especially important because there are currently no resistant tobacco varieties available.
About Corteva Agriscience™, Agriculture Division of DowDuPont
Corteva Agriscience™, Agriculture Division of DowDuPont (NYSE: DWDP), is intended to become an independent, publicly traded company when the previously announced spinoff is complete by June 2019. The division combines the strengths of DuPont Pioneer, DuPont Crop Protection and Dow AgroSciences. Corteva Agriscience provides growers around the world with the most complete portfolio in the industry — including some of the most recognized brands in agriculture: Pioneer®, Encirca®, the newly launched Brevant™ Seeds, as well as award-winning Crop Protection products — while bringing new products to market through our solid pipeline of active chemistry and technologies. More information can be found at www.corteva.com.
™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Telone is a federally Restricted Use Pesticide. In Florida, refer to the 24(c) Telone product specimen label for restrictions in certain counties. Telone is labeled under FIFRA 24(c) for nematode suppression in cotton and as an at-plant application only in the state of Georgia. Telone is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2018 Dow AgroSciences LLC
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