Early Identification Of Palmer Amaranth Essential In Reducing Yield Loss

Is it waterhemp or Palmer amaranth? Though identification can be difficult, University of Illinois associate professor of weed science Aaron Hager said early and accurate identification of Palmer amaranth plants coupled with implementation of an integrated management program are essential to reduce the potential for crop yield loss due to interference of this broadleaf weed.

Accurate identification of weedy Amaranthus species during early vegetative stages can be difficult because many look very much alike, Hager explained. “During the 1990s, waterhemp provided an excellent example of how difficult it can be to differentiate among the various Amaranthus species, especially when plants are small,” he added.

To assist weed management practitioners in accurately identifying Palmer amaranth, Hager said researchers in the U of I crop sciences department will accept tissue samples from suspected Palmer amaranth plants and use tools of molecular biology to identify whether the sample is Palmer amaranth or another species of Amaranthus. Information on how to collect and submit tissue samples from suspected Palmer amaranth plants is described on the Palmer amaranth identification form, found here. Download the form, provide as much information as possible and submit it along with the tissue samples to the address listed at the top of the form.

“Proper management of Palmer amaranth populations can help reduce the potential for seed production that will augment the soil seedbank and perpetuate the population in future growing seasons,” he said.

Palmer amaranth (Amaranthus palmeri) is a summer annual broadleaf weed species taxonomically related to other pigweed species (waterhemp, smooth, redroot) common in Illinois agronomic cropping systems. Hager said Palmer amaranth is not indigenous to Illinois, but rather it evolved as a desert-dwelling species in the southwestern United States, including areas of the Sonoran Desert. “Genotypic and phenotypic adaptability have allowed Palmer amaranth to expand its distribution and colonize the vastly different agricultural landscapes across much of the eastern half of the United States, including Illinois,” he explained.

Research has demonstrated that Palmer amaranth has a higher growth rate and is more competitive than other pigweed species. “Growth rates approaching 3 inches per day and yield losses of 78% (soybean) and 91% (corn) attributed to Palmer amaranth interference have been reported in the scientific literature,” Hager said. “Seed production capability of female Palmer amaranth plants is similar to that of female waterhemp plants.”

Hager described the cotyledon leaves of Palmer amaranth as being relatively long compared with other Amaranthus species. “Like all weedy Amaranthus species in Illinois, the true leaves — those produced after the cotyledon leaves — of Palmer amaranth have a small notch in the tip. Occasionally, a single hair can be found in the leaf notch. This hair may not be present in each leaf notch of a Palmer amaranth plant, and tends to be less common on leaves of waterhemp plants. The stems and leaves have no or few hairs and the stems feel smooth to the touch. Leaves are alternate on the stem and are generally lance-shaped or egg-shaped with prominent white veins on the underside,” he said. “As plants become older, they often assume a poinsettia-like appearance and sometimes have a white or purple chevron on the leaves. Leaves are attached to the stem by petioles that are usually longer than the leaf blade.”

Leave a Reply

Herbicides Stories

Crop InputsArkansas Plant Board Votes to Ban Dicamba — Now What?
June 23, 2017
The Arkansas State Plant Board has voted to pass a proposed emergency rule to ban the use of in-crop dicamba, Read More
Engenia soybeans
Crop InputsBASF: ‘Closely Monitoring’ Dicamba Situation in Arkansas
June 22, 2017
BASF, whose Engenia herbicide is the target of more than 200 drift complaints in Arkansas, emailed the following statement to Read More
Palmer pigweed seedhead in cotton
Crop InputsThreat of Dicamba Ban Looms in Arkansas
June 22, 2017
The Arkansas State Plant Board has rejected a proposed ban on the use of dicamba herbicide, but a procedural error Read More
Power to Do More Contest Winners
HerbicidesDow AgroSciences Announces Three Winners in Power to Do More Contest
June 13, 2017
Thousands of votes have been cast and three farmers have been awarded the power to do more with a $10,000 Read More
Trending Articles
PrecisionAg Vision Conference
Precision AgPrecisionAg® Vision Conference: Focused on the Future
June 13, 2017
PrecisionAg® is pleased to announce the return of its PrecisionAg Vision Conference, October 10-12, 2017. Based on overwhelmingly positive response Read More
Redbanded-stinkbug-on-soybean-Photo-credit-Thomas-County-Ag
Crop InputsExperts: Mild Winter, Early Planting Will Increase Soybean Insect Threat
June 12, 2017
Higher than average temperatures this past winter affected much of the nation, especially the South and Midwest. The National Centers Read More
Eric SfiligojMonsanto ‘Picks Its Battles’ by Nixing Deere Deal
May 23, 2017
Having been in the trade journalism game since the mid-1980s, I remember several watershed moments during my career. One of Read More
Migrant farm workers
LegislationTrump: Immigration Crackdown Won’t Impact U.S. Agriculture
May 16, 2017
President Donald Trump said he would seek to keep his tough immigration enforcement policies from harming the U.S. farm industry Read More
AGCO Ratliff featured
Eric SfiligojRemembering Robert Ratliff
May 15, 2017
With all the fast-paced happenings in agriculture this spring, with multiple mergers in the works and planting season in full Read More
Case sprayer nozzle closeup
EquipmentSpray Application: A Nozzle Renaissance
May 2, 2017
If you had asked four-decade ag veteran Mark Bartel, President of Wilger Inc., just a few years ago what lay Read More
Latest News
Crop InputsArkansas Plant Board Votes to Ban Dicamba — Now W…
June 23, 2017
The Arkansas State Plant Board has voted to pass a proposed emergency rule to ban the use of in-crop dicamba, Read More
Engenia soybeans
Crop InputsBASF: ‘Closely Monitoring’ Dicamba Situatio…
June 22, 2017
BASF, whose Engenia herbicide is the target of more than 200 drift complaints in Arkansas, emailed the following statement to Read More
ManagementConsolidation Update
June 22, 2017
Editors Paul Schrimpf and Eric Sfiligoj discuss progress on manufacturer consolidation, and another big move for Midwest cooperative Central Valley Read More
Palmer pigweed seedhead in cotton
Crop InputsThreat of Dicamba Ban Looms in Arkansas
June 22, 2017
The Arkansas State Plant Board has rejected a proposed ban on the use of dicamba herbicide, but a procedural error Read More
Potash Agrium
Crop InputsAgrium-PotashCorp to become Nutrien upon Merger Complet…
June 21, 2017
Potash Corporation of Saskatchewan Inc. and Agrium Inc. have announced today that once the anticipated merger transaction closes, the new Read More
Crop InputsMidwestern BioAg Hosts TerraNu Fertilizer Plant Opening…
June 20, 2017
Last Friday, Midwestern BioAg was joined by over 80 local farmers, media and staff to celebrate the grand opening of Read More
Soybean Field
Industry NewsAligned Ag Distributors Names New President
June 19, 2017
Aligned Ag Distributors LLC announced this morning the appointment of Mary Tolke to the position of President/CEO, effective July 1. Read More
ManagementPlotting Corn, AGCO/Asmark’s Applicator Training Center…
June 15, 2017
Editors Paul Schrimpf and Eric Sfiligoj talk about their recent visits to Columbus, OH, and Bloomington, IL, along with an Read More
Seed/BiotechDow AgroSciences Announces Launch of Enlist Corn for 20…
June 14, 2017
Enlist corn will be commercially available in the U.S. for the 2018 growing season. Dow AgroSciences announced the launch today Read More
ASMARK AGCO Applicator Training Center
EmployeesAsmark, AGCO Open Training Center for Beginning Applica…
June 13, 2017
AGCO Corp. and the Asmark Institute have opened a new Applicator Training Center, created in a collaboration between the two Read More
Power to Do More Contest Winners
HerbicidesDow AgroSciences Announces Three Winners in Power to Do…
June 13, 2017
Thousands of votes have been cast and three farmers have been awarded the power to do more with a $10,000 Read More
Frogeye leaf spot
FungicidesStrobilurin-resistant Frogeye Leaf Spot Threat Looms wi…
June 13, 2017
Heavy spring rainfall throughout the South and Midwest delayed planting and created the perfect environment for diseases like frogeye leaf Read More
PrecisionAg Vision Conference
Precision AgPrecisionAg® Vision Conference: Focused on the Future
June 13, 2017
PrecisionAg® is pleased to announce the return of its PrecisionAg Vision Conference, October 10-12, 2017. Based on overwhelmingly positive response Read More
CHS St. Paul, MN fertilizer terminal
LegislationICGA Praises President Trump’s Remarks on Waterwa…
June 12, 2017
Illinois Corn Growers Association President Justin Durdan, a farmer from Utica, issued the following statement regarding President Donald Trump’s comments Read More
Wheat Growers
UncategorizedWheat Growers Names Tracy Linbo as Senior Vice Presiden…
June 12, 2017
Wheat Growers has hired Tracy Linbo as Senior Vice President of Agronomy. Linbo joins Wheat Growers after having served 10 Read More
EquipmentAgTech Summit Aiming High for Modern Farming Solutions
June 12, 2017
THRIVE AgTech, in partnership with SVG Partners and Forbes, is hosting the third annual Forbes AgTech Summit June 28-29 in Read More
Central Valley Ag Randolph, NE
Precision AgLand O’Lakes Invests in EFC Systems
June 12, 2017
Land O’Lakes, Inc. has made a minority equity investment in EFC Systems, Inc., an ERP (Enterprise Resource Planning) and precision Read More
BRANDT
Crop InputsBRANDT Products Approved for Use with New Cropping Syst…
June 12, 2017
BRANDT, a leading manufacturer of specialty products for the agriculture and turf markets, has announced that 11 BRANDT formulations have Read More