ndsucpr_L_sm_W.jpg (13414 bytes)
weeds_Logo_Lg.jpg (6562 bytes)


ISSUE 8   June 21, 2001

 

AIM ON SOYBEAN

Aim is incorrectly listed for use as a broadcast application in the soybean section on page 90 of the NDSU Weed Control Guide Tour. DO NOT use Aim POST on soybean.

Aim does have a label for use in soybean ONLY as a directed application between soybean rows. If Aim was incorrectly sprayed as a general broadcast application severe soybean injury and death will occur.

 

APPLICATION TIMING ON WHEAT

Wet weather has delayed timely herbicide application in wheat. In some cases wheat may be at or beyond the growth stage where most herbicides can be applied. Page 12 of the 2001 ND Weed Control Guide shows the application timing of most herbicides labeled in wheat. Only a few herbicides are labeled for wheat at or prior to flag leaf emergence. 2,4-D, MCPA, Ally, Amber, bromoxynil, and Starane are a few. No herbicides are registered for application beyond the boot stage except for those on page 15 under the small grain preharvest section. No herbicides should be applied beyond the boot stage due interference with flowering, pollination, fertilization and kernal fill. Ultimately, herbicides applied at this time will leave an illegal residue in the seed and/or reduce yield.

Two herbicide with a somewhat ambiguous application window is Discover and Puma. The end growth stage of wheat for Discover is emergence of 4th tiller. Depending on environmental conditions this could be anywhere in the tillering to preboot stage. Puma can be applied until 60 days prior to harvest. Harvest is sometimes delayed for extended periods due to climatic conditions, agronomic factors like swathing, and even farmer preference. The flexibility in this 60 day preharvest interval allow Puma to be applied to wheat in an advanced stage.

 

CALLISTO TANKMIX WITH POST GRASS HERBICIDES

2 (ee) labels have been issued allowing Callisto to be tankmixed with Accent,, Accent Gold, Basis Gold, and Steadfast. All label directions and restrictions must be followed including crop stage at application and adjuvant use.

Richard Zollinger
NDSU Extension Weed Specialist
rzolling@ndsuext.nodak.edu

 

LABELS LIMIT SPRAYING FOR POST APPLICATIONS IN CORN

Use of postemergence corn herbicides dictates knowing when to apply the herbicides. Limitations on harvest intervals between when you spray and when you may harvest must also be kept in mind. Remember the label will provide you all of this information. Much spraying has been occurring in the Valley over the last two weeks. Keep in mind that many herbicides work better under the humid conditions we have been experiencing recently. Also, cool nights will slow down the metabolism of the herbicides through the corn plants and may limit the harmless breakdown of the absorbed chemicals in the corn plant causing weakening or stunting of corn in some cases on certain herbicide modes of activity. As corn gets taller, remember to be careful with sprayer nozzle positioning for those herbicides that can be used later by spraying with drop nozzles. Morning spraying can increase herbicide activity (or cause slight corn injury especially after cold nights) by the morning dew on the corn plant along with the upright leaf structure of the plant allowing chemical to funnel and run directly down into the corn plant whorl. Some general application restrictions include:

 

LABELED LIMITS FOR POST APPLICATIONS ON SOYBEANS

The following label limits are approved for post applications in soybeans. Remember to carefully consider the weather and crop conditions before making a herbicide application.

Denise McWilliams
Extension Crop Production Specialist
dmcwilli@ndsuext.nodak.edu


cprhome.jpg (3929 bytes)topofpage.jpg (3455 bytes)tableofcontents.jpg (4563 bytes)previous.jpg (2814 bytes)next.jpg (1962 bytes)