Pre-emerge Herbicides Can Control Resistant Pigweed - October 5, 2009
With Ken Smith Extension Weed Specialist
[Title Slide – Pre-emerge Herbicides Can Control Resistant Pigweed; With information from Ken Smith, Extension Weed Specialist; Your Soybean Podcast, University of Arkansas Division of Agriculture, Arkansas Soybean Promotion Board]
[Ken Smith standing in a field] Good day, I’m Ken Smith University of Arkansas Division of Agriculture Weed Scientist. Here today in a soybean field that’s not uncommon for other farmers in the state where we’ve got herbicide resistant pigweed. These pigweeds are all glyphosate resistant. This field has been sprayed numerous times with glyphosate and as you can see, [video shows pigweed in a field] the pigweed infestation is quite severe.
[Ken Smith] Yields will be reduced, and many of our farmers are asking what do I need to do for next year. We know we’ve lost this year but think about next year. I’d like to show you some of our programs in Round-up Ready soybean for program considerations next year.
This is a part of the program that I’d like to do, to share with you some of our successes in our research plots. I think that if we look at this it tells a real story as to where we need to be next year in some of our production practices.
In this particular study that we are standing in the middle of here, [picture of a soybean field that received pre-emerge herbicide] half of this study got a pre-emerge herbicide, [picture of a soybean field that received no pre-emerge herbicide] the other half got no pre-emerge. Now, the half that got pre-emerge, it really does not matter which pre-emerge we use, it could be Prefix, it could be Authority MTZ, it could be Valor but in this particular program, as we can see, this side of the field is clean. [Picture of a soybean field. Clean soybean test plot sprayed with a herbicide before weeds emerge.] And we used a residual herbicide up front we came back with Round-Up, then we came back with Round-Up plus Dual over the top. So we have used a pre-emerge plus another application of Dual, [Picture of a clean soybean field.] a second application of a residual herbicide.
[Ken Smith] Now certainly that is more than what we have just looked at in the study where we just saw Round-Up followed by Round-Up and more than what we see in this part. [Picture of a soybean field with weeds. Soybean test plot sprayed with a herbicide post-weed emergence.] But now in this half of the study many of the same chemicals are applied. For instance in some of this we had Prefix applied post-emergence rather than pre-emerge and where we applied it post-emergence we’ve got infestations. [Picture of a soybean field with weeds.]
[Ken Smith] I think that this is a really, really important point for us next year in our production practices to consider the importance of pre-emerge weed control in soybeans in our glyphosate resistant pigweed areas.
[Narrator] Your Arkansas Soybean Podcast is a production of the University of Arkansas Division of Agriculture and was funded in part by the Arkansas Soybean Promotion Board. For more information on soybean farming in Arkansas contact your local county Extension Office. [Title slide - For more information contact your local county Extension office. Your Arkansas Soybean Podcast, University of Arkansas Division of Agriculture, Arkansas Soybean Promotion Board]