• Tough weeds such as waterhemp, Palmer amaranth, and giant ragweed are highly competitive and, particularly with the spread of glyphosate resistance, can be difficult to manage once they get out of control. Post-emerge options can be limited, especially in soybeans.
In soybeans, early-season weed competition poses a potential 6 to 10 percent yield loss.
In corn, weeds allowed to reach 4 to 6 inches in height can reduce yield potential by 3 percent and 7 percent, respectively.
The potential losses due to weeds total almost $10 billion, based on current national projected yields and commodity prices.
Growers should plan pre-emergence applications of a residual herbicide now to help prevent that from happening.
“If you miss weeds early, they get bigger and tougher to control, potentially requiring multiple applications and/or higher use rates for effective control,” said Dan Westberg, Technical Market Manager with BASF. “That early-season weed competition ends up costing farmers more money and diminishes their yield potential.”
Thomas Bauman, Purdue University weed scientist, noted that a field always has its highest yield potential when weeds have yet to appear.
“We recommend eliminating that early season weed competition so you get a higher yield,” said Bauman. “The other thing it does, particularly for some of our larger growers who are farming literally thousands of acres, is provide a bigger window for a timely post-application because we control that earlier flush of weeds.”
Tough weeds such as waterhemp, Palmer amaranth, and giant ragweed are highly competitive and, particularly with the spread of glyphosate resistance, can be difficult to manage once they get out of control. Post-emerge options can be limited, especially in soybeans.
“Weather also can make post-emerge applications difficult, since it can be unpredictable and keep applicators out of their fields when they most need to be there,” Westberg said. “That’s why we hear from growers that it can be easier to control weeds earlier in the season, when application timing isn’t as difficult to manage.”
Additionally, by eliminating early-season weed competition and allowing a wider, more effective post-emerge application window, a preemerge application of a residual herbicide helps protect a grower’s seed and fertilizer investments.
A pre-emerge application also provides an opportunity to introduce a different site of action in a herbicide program to reduce the potential for resistant weeds to develop.
“We look at the best management practices to recommend, and number one would be different sites of action,” said Kevin Bradley, University of Missouri weed scientist. “My recommendation for a different site of action comes in the form of a pre-emergence herbicide, because it is the most efficacious and economical for you.”
With innovative solutions, technical support and educational tools, BASF is the grower’s number one partner for managing weed resistance by providing more corn and soybean herbicide sites of action than any other crop protection company.
“BASF offers a number of effective pre-emerge herbicide options, including Verdict herbicide for corn and new OpTill PRO herbicide for soybeans,” Westberg said. “These are products that are powered by Kixor herbicide technology and provide enhanced residual control to help growers minimize the impact weeds — including waterhemp, Palmer amaranth and giant ragweed — will have on their bottom line.”
Recently released results from two years of crop protection research trials showed that the weed-control benefits from a pre-emerge application of a BASF product helped increase soybean yields by an average 2.3 bushels per acre over a 2,4-D plus glyphosate pre-emerge application. In corn, a pre-emerge application of a BASF product increased yields by an average 19.5 bushels per acre.
“BASF is committed to providing growers with new chemistries and products to help maximize their yield potential and proactively manage weeds,” Westberg said. “These results — as well the recent launches of OpTill PRO and Armezon herbicides — are a prime example of that effort.”
For more information about weed resistance management, visit http://agro.basf.us/stewardship/herbicide-best-practices.html.