Fend off soybean weeds and diseases
Soybeans often hover in corn's shadow. It's not like this when it comes to pests, though. Glyphosate-resistant weeds and diseases pay plenty of attention to this legume. Meanwhile, some reports link manganese deficiencies to glyphosate applications on soybeans.
The good news is ways exist to mash these maladies. Companies are developing herbicides and traits to complement glyphosate-tolerant systems. Fungicides and disease-resistant varieties help corral diseases. Meanwhile, most studies show no conclusive link between glyphosate applications and manganese deficiencies.
Here are some factors to consider as you plot future soybean strategy.
“There are weeds that are getting harder and harder to control with glyphosate,” says Bruce Battles, Syngenta Seeds agronomy marketing manager.
That's led to several new soybean herbicides and herbicide-tolerant traits now on the market or in the works. LibertyLink soybeans from Bayer CropScience debuted in 2009. BASF launched Kixor, a new PPO inhibitor compound, in 2010.
Joining these later this decade will be HPPD-tolerant traits from Bayer and Syngenta. These traits give crop tolerance to HPPD-inhibitor herbicides like mesotrione (Callisto) and isoxaflutole (Balance Pro). Officials from both companies say this trait will help complement glyphosate in the herbicide mix and extend the effectiveness of glyphosate.
Dow AgroSciences plans to commercially launch its Dow Herbicide Technology in soybeans in 2015.
“This brings in 2,4-D tolerance,” says Damon Palmer, DHT commercialization leader for Dow AgroSciences. “We are looking to partner it with glyphosate. Growers will be able to enjoy the benefits of glyphosate-tolerant systems and control the weeds glyphosate is increasingly missing like marestail, morningglory, giant ragweed, and common ragweed.”
Monsanto plans to release a dicamba-tolerant trait in 2014, pending regulatory approval. This will be used to complement glyphosate-tolerant soybean varieties and add another mode of action, say company officials. After the dicamba-tolerant trait debuts, Monsanto plans to team it with the Roundup Ready 2 Yield trait.
Also on deck for soybeans pending regulatory approval is Optimum GAT. This is a new glyphosate-tolerant trait with ALS inhibitor activity from Pioneer Hi-Bred and DuPont.
Mark it up
It will be more difficult to keep track of all these different technologies. It's easy to say you'd never apply glufosinate (Ignite) on glyphosate-tolerant (Roundup Ready) soybeans.
In the heat of battle, though, it may be easier to inadvertently apply the wrong compounds than you think. Mixing up herbicides on herbicide-tolerant systems ensures killing of both crops and weeds.
“A flagging system is going to be essential for these technologies,” says Steve Stevens, a Tillar, Arkansas, farmer.
The University of Arkansas has done just that with its Flag The Technology program. It uses color-coded bicycle-type flags conspicuously placed in the field visible from ground and air. Red signifies conventional varieties, white represents Roundup Ready technology, bright green signals LibertyLink systems, and bright yellow represents Clearfield systems.