Root-Knot Nematodes - July 2012
[University of Arkansas Division of Agriculture Research and Extension University of Arkansas System. Arkansas Soybean Promotion Board. Dr. Terry Kirkpatrick, Professor and Menatologist, Plant Pathology, Southwest Research and Extension Center.] [Video shows Terry Kirkpatrick standing in a soybean field holding plants with nematode damage.]
[Dr. Kirkpatrick] One of the issues we’re having to deal with in this field is the root knot nematode. And you can see from these galled roots where the nematode gets its name. Nematodes, for those who are not familiar with them, are microscopic round worms that live in the soil. [Picture shows a highly magnified view of immature root-knot nematodes attacking a root tip. Photo courtesy of Nemapix.]
And so, as we begin to think about the damage that is done think about the plant and how the water flows from the roots to the plant. The root-knot impairs the root system to such a degree that water up-take and translocation is pretty well shut down. [Video shows roots of plant with nematode damage and a soybean field.]
Controlling nematodes is sometimes pretty difficult, the options that are available to the farmers are genetic resistance, choosing a resistant variety; the unfortunate truth of that, however, is many of our early maturing varieties are susceptible and those that are most popular many of them are susceptible.
This is Mr. Felix Smart, who owns this farm. Felix, what is your plan for managing this nematode over the next few years?
[Felix Smart, Soybean Producer, Jefferson County] “Well, I think that we will put it in corn next year, and then maybe two years, because we have a weed issue also. [Dr. Kirkpatrick “right”] [Mr. Smart] So were going to control that, try to get that under control. And then probably rice. [Dr. Kirkpatrick “excellent”] [Mr. Smart] And then try soybeans and kind of see where we stand from there.”
[Dr. Kirkpatrick] This is going to be an excellent rotation on a lot of levels, certainly the weed management is a separate issue from the nematodes management issue, but all of them have to be done. From a rotation standpoint relative to nematode management, corn is a host for root knot, for this root knot, but it is not really damaged much by the nematodes. So the crop can be grown profitably here in presence of nematodes. Rice on the other hand, is not a host and the flooding actually will kill the nematodes. A lot of the nematodes won’t survive a year of flood.
For more information you can contact your local county extension agent, or you can go to www.uaex.edu. [www.uaex.edu. University of Arkansas Division of Agriculture Research and Extension University of Arkansas System, Arkansas Soybean Promotion Board.]