LibertyLink soybeans slated for 2009
You'll have another option for weed control in soybeans in 2009 when Bayer CropScience rolls out LibertyLink soybeans.
Bayer officials discussed the LibertyLink rollout at this week's Commodity Classic in Nashville, Tennessee. They are positioning LibertyLink as the only other non-selective herbicide option to glyphosate.
Liberty has a different mode of action, and growers will need to tweak their management strategy in comparison to glyphosate, say Bayer officials. However, farmers will still retain a non-selective strategy as they have with glyphosate.
"The bottom line is, we're going to give farmers another choice," says Arlene Cotie, Bayer communications and trait integrity manager. Both domestic and foreign approvals are on track for a 2009 launch, she adds.
Glyphosate is convenient, easy to use, and cost effective. The downside is high use has likely selected for glyphosate-resistant weeds. For example, a 2007 survey of agricultural retailers stated four percent of Missouri soybean acres have glyphosate-resistant waterhemp.
Rotating glyphosate with the LibertyLink system is one way to retain the convenience of non-selective weed control and extend glyphosate's effectiveness, say Bayer officials.
Bayer is working with around 85 seed companies to offer LibertyLink soybean varieties next year. Bayer is working with Soygenetics LLC in West Lafayette, Indiana, in developing these varieties.
In 2009, 23 LibertyLink varieties ranging from mid-group zero to late group four maturities will be marketed to farmers, says Frank Spelbring, vice president of marketing for Soygenetics.
In company tests, yields of LibertyLink varieties have been competitive with glyphosate-tolerant varieties, and have no yield drag, says Spelbring. There may be cases where not all desired agronomic traits are in all varieties. For example, they are working to get resistance to soybean cyst nematode in LibertyLink varieties in 2009.
"This happens anytime a new trait comes in," says Spelbring.
Over time, though, desired traits make it into such varieties, says Spelbring.
You'll have to tweak your application strategy when it comes to applying Liberty. Glyphosate and glufosinate (Liberty's active ingredient) are both non-selective herbicides. Glyphosate is systemic, meaning it moves through the plant after contacting a plant part.
Meanwhile, glufosinate is a contact herbicide, killing only what it touches. To kill weeds, applicators will need to thoroughly coat them with glufosinate. To do this, nozzles that create a medium-sized spray droplet work best, says Andy Hurst, LibertyLink product manager. Effective glufosinate applications will also require at least 15 gallons per acre of water, he adds.
Timing is also key. Bayer officials advise treating with glufosinate no later than 22 days following weed emergence.
One option for a program may be a preemergence application of residual herbicides like Prowl or Valor, followed by the postemergence glufosinate application, Hurst says.