How Much Do Weed Escapes Cost?
As harvest wraps up, it's time to reflect on this year's cropping decisions. One of the things you should be thinking about is your weed control. Did your weed control program do its job this year? Did you really get the best yields or did weed escapes get in the way of your profits? The answers to these questions will influence the decisions you make for 2014.
Overreliance on a single weed control method causes resistant weeds to develop. It also adds to the risk of a consequential loss of a particular herbicide-tolerant system, and may eventually jeopardize the ability to grow a specific crop in a specific field. Growers face additional costs to control resistant weeds through unplanned herbicide applications, intense manual labor, and in extreme cases, total crop loss. Use Integrated Weed Management (IWM) practices for successful management of a resistant weed population.
Weeds that emerge with the crop, or shortly thereafter, have the greatest potential to adversely impact yields. The yield loss associated with this flush of weeds is strongly influenced by how long weeds are allowed to remain in the field and compete with crops for light, water and nutrients.
Soybean Yield Losses
According to Purdue University research, season-long competition by waterhemp (more than 20 plants per square foot) reduced soybean yields 44 percent in 30-inch rows and 37 percent in 7.5-inch rows. Waterhemp that emerged as late as the V5 soybean growth stage reduced yields up to 10 percent.1
Studies out of North Carolina State University and the University of Georgia2 in 2012 show soybean yield loss of as much as 68 percent as a result of Palmer amaranth interference at a density of one plant per square foot.
Corn Yield Losses
Research indicates that delaying a postemergence herbicide application until weeds are 6 inches tall results in a significant yield loss. Many factors come into play, such as weed species and the density of the plant present.
Early season competition from a heavy waterhemp infestation (more than 30 plants per square foot) reduced corn yields 15 percent by the time the waterhemp was 6 inches tall. With lower waterhemp densities (less than 10 plants per square foot), yields were reduced by only 1 percent when waterhemp was controlled at 6 inches.1
Canola Yield Losses
Research3 in western Canada has shown that a 5 percent yield loss in canola can result from just two weeds per square meter.
Making informed decisions are imperative to your profitability. The above information can help you make those decisions for your operation in preparation for 2014 and beyond.
The LibertyLink System Protects Yields, Controls Weeds
Crops with the LibertyLink® trait provide excellent weed control and preserve the yield of your high-performing varieties. By using LibertyLink growers can spray Liberty® in-crop for nonselective postemergence control of even the toughest weeds, including Palmer amaranth, giant ragweed, waterhemp and marestail, as part of an IWM program. With a unique mode of action, Liberty allows growers to control weeds within days, not weeks, under favorable conditions.
- With soybean seed available through more than 100 seed companies, growers can manage their weed pressures with LibertyLink varieties that fit their growing conditions.
- LibertyLink corn hybrids are available in Herculex®, SmartStax® and Agrisure® hybrids with corn borer protection. They are also available as in-bag refuge products in Genuity® SmartStax RIB Complete®, Refuge Advanced® powered by SmartStax, Optimum® AcreMax®RW (AMRW), Optimum AcreMax (AM), Optimum AcreMax XTRA (AMX), Optimum AcreMax 1 (AM1) and Optimum AcreMax XTreme (AMXT).
LibertyLink trait technology is part of the Crop Science commitment to leading innovation that enhances world food security through a robust pipeline of new seeds, traits and crop protection solutions.
The right residual program will save time and money. In this photo, Verdict® followed by Liberty controls Palmer amaranth in soybeans.
- Nordby, Dawn, Bob Hartzler, and Kevin Bradley. "Biology and Management of Waterhemp." The Glyphosate, Weeds, and Crop Series. Purdue Extension. Nov. 2011. Web. http://www.extension.purdue.edu/extmedia/BP/gwc-13.pdf.
- Chandi, Aman, et al. "Interference of Selected Palmer Amaranth (Amaranthus Palmeri) Biotypes I Soybean (Glycine Max)." International Journal of Agronomy. 2012 (2012): 1-7. Print.
- "Canola Grower's Manual." Canola Council of Canada n.p. n.d. Web. 2003.http://www.canolacouncil.org/canola_growers_manual.aspx.
Verdict is a trademark of BASF Corporation. Herculex Insect Protection Technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex and Refuge Advanced are registered trademarks of Dow AgroSciences LLC. Genuity, RIB Complete and SmartStax are registered trademarks of Monsanto Technology LLC. AcreMax and Optimum are registered trademarks of Pioneer Hi-Bred. Agrisure is a trademark of a Syngenta Group Company.