LibertyLink Soybeans As A Weed ManagementTool

With weed resistance quietly developing throughout Minnesota and the Dakotas, LibertyLink soybeans are gaining interest with regional growers as a rotational tool in their weed management program.

Many farmers have moved to a high, if not 100%, glyphosate resistance weed control program. It is easy to understand that if problem weeds do slip through, dirty fields will soon follow. When just five plants remain per acre, they can potentially produce up to 400 plants / acre the following year.  And by year three, there is the potential of 32,000 plants / acre producing resistant seed.

We have watched the weed resistance problem gain momentum as it has moved from Missouri and Arkansas through the Midwest and now into our part of the world. Common Ragweed, Giant Ragweed, Waterhemp, and Common Lambsquarters have all been identified in our region as resistant to glyphosate. So far, the problem has been in isolated areas and is not widespread yet. But it will not take long to spread if not controlled.

Recognizing the need in this region, particularly with sugarbeet growers, our company now offers a full lineup of LibertyLink soybeans across maturities. These varieties are able to compete with any of the RoundupReady varieties on-the-market and have the agronomic traits to handle our variable soil conditions. Most of the current varieties have great IDC tolerance and Soybean Cyst Nematode resistance as well.

Ignite herbicide for LL soybeans is the only alternative, on the market, to glyphosate for complete weed control. I have used Liberty/Ignite since it became available in the early 90s with Bt corn. It really fits better with soybeans because we are spraying in warmer conditions. There are also tank-mix options for grass control issues if they arise. LibertyLink soybeans also control volunteer RR crops from the previous year, including corn and canola. We saw excellent control this year in the fields we examined. Even with the wet weather and the several applications made by air, excellent weed control was achieved.

Don’t get me wrong though – LL soybeans are not the only answer to weed resistance. Another management strategy we need to embrace is the use of  pre-emerge herbicides in both our corn and soybean fields. This practice is becoming essential because: a) early weeds do the most damage to yield; b) a pre-emerge gives timing flexibility with post-applied herbicides; and c) university data has shown increased yields by including pre-emerge chemicals in your program.

Another management strategy to look at is tank-mixing other herbicides with glyphosate in post-applied applications. There has been more research on this lately and chemical companies have some very good options. Talk to your local chemical supplier for recommendations.

This winter, get educated on what the weed resistance pattern looks like in our region. And then think through the various options available to you as you plan your farm’s weed management program.