Liberty (glufosinate ammonium: 24.5%) is a contact, broad-spectrum, non-selective herbicide for weed control in Liberty Link corn and soybean and a corn hybrid stack with glyphosate and Liberty tolerance. A recent update in the Liberty label will provide an opportunity to apply Liberty at higher rates in Liberty Link corn and Liberty Link soybean.
Six weeds in Nebraska are resistant to glyphosate. Liberty Link corn/soybean is an additional tool for control of such glyphosate-resistant weeds. Using diverse weed management tools is important to the control of herbicide-resistant weeds and to avoiding the further evolution of herbicide-resistant weeds.
Liberty can be applied from emergence up to V6 growth stage in Liberty Link corn and from emergence to R1 growth stage in Liberty Link soybean.
| Liberty Application Direction | Liberty Link Corn | Liberty Link Soybean |
|---|---|---|
| Application window | Emergence up to V6 | Emergence up to bloom or R1 growth stage |
| Application rate | 32 fl oz/acre; a second application can be applied at 32 fl oz/acre; additional application of 22 fl oz/acre can be made | 32 to 43 fl oz/acre; a second application can be applied at 32 to 43 fl oz/acre up to a yearly maximum of 87 fl oz/acre |
| Cumulative maximum per year | 87 fl oz/acre | 87 fl oz/acre |
| Adjuvants | Ammonium sulfate at 1.5 to 3 lb/acre | Ammonium sulfate at 1.5 to 3 lb/acre |
| Spray volume | 15 GPA minimum; if large weeds or unfavorable growing conditions are present, increase water volume to a minimum of 20 GPA. | 15 GPA minimum; if large weeds or unfavorable growing conditions are present, increase water volume to a minimum of 20 GPA. |
| Nozzle spray quality | Medium to coarse nozzles | Medium to coarse nozzles |
| Rainfast | 4 hours | 4 hours |
The Bottom Line
- The new increased application rate of Liberty can help effectively control weeds in Liberty Link corn/soybean.
- Do not rely only on Liberty for weed control in Liberty Link corn/soybean.
- It is important to apply pre-emergence herbicides with multiple effective modes of action within three days of planting Liberty Link corn or soybean. Pre-emergence, residual herbicides labeled for Roundup Ready corn or soybean can be applied in Liberty Link corn/soybean (Figure 1).
- Do NOT apply Liberty in Roundup Ready corn or Roundup Ready soybean or Roundup Ready 2 Xtend soybean (Figure 2a and 2b).
- Liberty is a contact herbicide; therefore, target applications to when weeds are less than 5 inches tall. Applying Liberty when weeds are too tall (more than 8 inches) will result in regrowth.
- If used according to label directions, the Liberty Link system can provide excellent control of glyphosate-resistant and hard-to-control weeds.
For more information, view the updated Liberty label.
Figure 2a and b. Unintended application of Liberty in Roundup Ready corn. Remember that Liberty should be applied only in Liberty Link corn or Liberty Link soybean for post-emergence weed control.
