Bollworm Infestation Warning - August 2012
[University of Arkansas Division of Agriculture Research and Extension University of Arkansas System. Arkansas Soybean Promotion Board. Gus Lorenz, Extension Entomologist, University of Arkansas Division of Agriculture, Lonoke Research and Extension Center]
[Video shows Lorenz standing in a soybean field.] I’m Gus Lorenz, Extension Entomologist with the University of Arkansas Division of Agriculture.
As you can see, I’m standing in front of a soybean field today. It’s mid- to late August, and as you can see behind me, I can see the ground down the middles. So we haven’t achieved canopy closure and that’s worst-case scenario for beans at this time of year to be infested with corn earworm. [Video shows soybean rows and soybean plants.]
You can see the size of the plant, you can see the stage of development that we’re in. We’re just beginning to bloom and set pods and right now in this particular field, we’re running right at five to six times threshold in this case. [Video shows soybean plants with bollworms on the plants.]
We’re currently evaluating a lot of insecticides and looking at what’s working for us. [Video shows Lorenz sweeping with a net to collect bollworms and then shows the worms collected in the net.] And I can tell you, we’re seeing really good control this year with Belt and Steward, we’re getting good control with pyrethroids plus a half a pound of acephate.
Unfortunately, the residual control in that situation is not very good. We’re getting at least three weeks it looks like based on our data with Belt, about two weeks or so with Steward. But this is the time of year when getting that sweep net out and taking a look at these fields can really save some yield for our growers.
For more information on sampling soybeans and developing worm problems in Arkansas, contact your local county agent.
[For additional information visit www.uaex.edu. University of Arkansas Division of Agriculture Research and Extension University of Arkansas System. Arkansas Soybean Promotion Board]