Glyphosate Resistant Pigweed in Round-up Ready Soybean - June 21, 2010
[Title Slide – Glyphosate Resistant Pigweed in Round-up Ready Soybean. Your Arkansas Soybean Podcast, University of Arkansas Division of Agriculture, Arkansas Soybean Promotion Board. Number 35 - June 21, 2010]
[Dr. Bob Scott, Extension Weed Scientist standing in a soybean field holding pigweed] Glyphosate resistant Palmer Pigweed is one of the most troubling weeds to try and control in Round-Up Ready or conventional soybeans. [Picture of a soybean field] The particular field that we are standing in here was determined the previous year to be fully infested with glyphosate resistant pigweed. [Picture of Dr. Scott walking across a soybean field] This year the Cooperative Extension Service came in and we recommended a residual program of Valor applied early in a burn-down, followed by Authority MTZ pre-emerge, followed by Flexstar GT early post. [Title slide - Valor Herbicide - Early Burndown, Authority MTZ pre-emerge, Flexstar GT early post.]
[Dr. Bob Scott] We‘re a few days out from that early post application now and we’ve basically [Picture of weeds that have been burned down] thrown several herbicides at this problem with fairly good results. One problem in controlling glyphosate resistant Pigweed in [Dr. Bob Scott] Round-Up Ready soybeans is that we need to use the concept of overlapping residuals. [Title slide - Overlapping Residuals. Valor Herbicide - Early Burndown, Authority MTZ pre-emerge, Flexstar GT early post.] In other words we try to use enough residual products to never let the pigweed get started.
[Title slide - Flexstar GT, Flexstar, early post-emergence pigweed control.] Flexstar GT or Flexstar does a pretty good job post-emerge controlling emerged Palmer Amaranth if we get them when they’re very small. [Slide showing pigweed that is 2-3 inches tall] Two to three inch Palmer Pigweed can be controlled early post with Flexstar. [Dr. Bob Scott showing two different pigweeds] If we let the Pigweed get too big such as the one in my left hand, we get very good burn [Slide - picture showing a pigweed that has been burned down] or necrosis of the plant however we get reemerging leaves and [Dr. Bob Scott] stems at the axillary buds and this particular pigweed will probably recover.
It’s very important to start early with a residual and stay on top of your early post program and spray pigweeds when they are very small in Round-Up Ready soybeans.
[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]