We now know there are no new herbicides with different sites of action in the pipeline, so many growers await the approval of the introduction of soybean varieties with various herbicide traits. For now, we are fortunate to have LibertyLink® soybeans. In recent years, their sales have skyrocketed. The Burrus/Hughes lineup of LibertyLink soybeans is: Hughes 236LL, Hughes 266LL, Hughes 285LL, Hoblit 355LL, Hoblit 384LL, Hoblit 405LL, Hoblit 423LL, and Hoblit 456LL. The use of Liberty® or glufonsinate, a contact herbicide, along with the Burrus LibertyLink soybeans lineup, can be an effective tool to combat weeds like waterhemp, that can be resistant to other herbicide groups. Burrus LibertyLink soybeans also offer yield.
We continue to teach our growers how to achieve successful weed control with a LibertyLink system:
- Before purchasing LibertyLink soybeans, check with your ag chemical supplier to make sure there will be an adequate supply of Liberty herbicide available.
- Start weed free – Fall/spring burndown or tillage might be needed to rid fields of weeds before planting. “Never plant into a stand of weeds, hoping for the best.”
- The use of a full-rate of a preplant residual herbicide product will help to reduce weed populations, slow weed growth, and offer more flexibility on when the post application of Liberty can be applied.
- Thorough weed coverage is key, when it comes to the application of Liberty because it is a contact herbicide. Better coverage with Liberty can be accomplished by particular nozzles (flat fan or others) that provide medium spray droplets (250 to 350 microns), with higher pressures (40 to 60 psi), at slower application speeds (12 mph or less), with the addition of lots of water - 20 GPA), along with adjuvants such as 2.5 to 3 lbs AMS per acre.
- Liberty is rainfast within 4 hours. Be sure not spray Liberty at night or under adverse conditions (fog, heavy dew, rain or stress such as drought, cool temperatures, and extended periods of cloudiness). Spray Liberty after dawn and 2 hours before sunset to avoid the possibility of reduced weed control.
- Apply the first post Liberty application (rate of 22-29 fl oz/A) 22 days after crop emergence or up to V3 soybean growth stage, before weeds reach a height above 3-4 inches. The higher rate (up to 36 fl oz/acre) of Liberty might be needed if environmental conditions prevent timely application and weeds are 6- 10 inches tall. However, an application of more than 22 oz. of Liberty is not recommended past V4 soybean growth stage.
- A second post Liberty application (rate of 22 to 29 fl oz/acre) can be applied if needed, but keep in mind that your total use rate of Liberty cannot exceed 65 fl oz/acre.
- The first and second applications of Liberty should be at least 5 days apart.
- Use a full rate of a post residual herbicide with your post Liberty application if needed for harder to control weeds such as amaranths.