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
HerbicidesScouting Key To Next Season’s Soybean Herbicide Program
August 12, 2014
When growing soybeans, growers need to think ahead to stay one step ahead of weeds. That means examining weed threats and evaluating which herbicides work best. Read More
HerbicidesArysta Touts Burndown Herbicide For Brome Management In Wheat
June 4, 2014
Arysta LifeScience North America recommends PRE-PARE Burndown Herbicide for effective brome management in winter wheat. Read More
HerbicidesFall Herbicide Applications More Effectively Manage Resistant Italian Ryegrass
May 14, 2014
Field studies show that a fall application of certain herbicides before weed emergence, leads to more successful crop planting and weed control in spring. Read More
Waterhemp in soybean stubble
HerbicidesThe Weed Resistance Problem: A Matter Of Billions
April 1, 2014
Not only is the amount of money being spent to control these yield robbers high, but the toll it has taken on the human population is growing lager by the day. Read More
Top 100 Articles
CropLife 100The Andersons Starts Venture Capital Subsidiary
January 26, 2015
The Andersons has established Maumee Ventures, a venture capital subsidiary designed to foster promising innovations that strategically align with the company’s core businesses. Read More
CropLife 100CHS Partners With Northern Partners Coop On Fertilizer Warehouse
January 21, 2015
In addition, the two companies will form a joint venture to build and operate a grain barge loading facility that will handle corn, soybeans and wheat for export through the CHS terminal at Myrtle Grove, LA. Read More
CropLife 100Wilbur-Ellis Move To Colorado Complete
January 20, 2015
Wilbur-Ellis Co. announces the opening of its new Agribusiness Division location in the Denver, CO, Metro Area. The new facility will host key personnel as the company shifts the base of its Agribusiness operations from California to Colorado. Read More
CropLife 100United Suppliers, McGregor Co., Five Others To Form Aligned Ag Distributors
January 20, 2015
These companies will continue to operate as independently owned and operated businesses, however, their crop protection divisions will now be formally aligned under the umbrella of Aligned Ag Distributors. Read More
CropLife 100Bozeman Named SEEDWAY Chief Operating Officer
January 16, 2015
He succeeds Donald Wertman, who will retire at the end of August 2015 after 40 years with the GROWMARK subsidiary. Read More
CropLife 100Wilbur-Ellis’ Craig Bair Honored For Safety Contributions To Ag Aviation
January 14, 2015
The William O. Marsh Safety Award recognizes significant achievements in safety, safety education or an outstanding operational safety program. Read More
Latest News
FertilizerH.J. Baker Hires New Crop Protection Marketing Manager
January 27, 2015
As Marketing Manager for the Crop Performance division, Usman Khalid will work out of H.J. Baker’s global headquarters in Westport, CT, and will drive new initiatives for the division. Read More
CropLife 100The Andersons Starts Venture Capital Subsidiary
January 26, 2015
The Andersons has established Maumee Ventures, a venture capital subsidiary designed to foster promising innovations that strategically align with the company’s core businesses. Read More
Exclusive state-of-the art Stueve Construction designed “Vista View” Elevated Control Room.
Eric Sfiligoj2015 Agricultural Market Read: Mixed
January 26, 2015
The agricultural market could look radically different this year, profit-wise, depending upon which segment you do business in. Read More
Edward Chell Biosafe
Crop InputsBioSafe Systems Names Ed Chell California Territory Man…
January 26, 2015
BioSafe Systems has announced the recent addition of Ed Chell as California Territory Manager for the agrichemical division, supporting the crop protection, water treatment and food safety business segments. Read More
InsecticidesBayer CropScience Introduces Sivanto Insecticide
January 26, 2015
Sivanto precisely targets key damaging pests at multiple insect life stages to prevent damage to plants and help minimize the spread of diseases from insect carriers. Read More
ManagementRetail Collaboration, Communicating Agriculture’s Good …
January 23, 2015
Editors Paul Schrimpf and Eric Sfiligoj discuss the recent creation of Aligned Ag Distributors, and the US Farmers and Ranchers Read More
FertilizerOSU Expert: Toledo Water Crisis A Turning Point For Ohi…
January 23, 2015
The August 2014 water crisis in Toledo, OH, impacted Ohioans’ views of Lake Erie algae problems by increasing the attribution of blame of algae growth on agriculture. Read More
FertilizerH.J. Baker Launching TIGER XP
January 22, 2015
Tiger-Sul introduces this next generation sulphur-bentonite product with a proprietary activator – ensuring farmers have a well-balanced nutrient replacement program. Read More
Crop InputsH.J. Baker Expands China Sales Force
January 21, 2015
Global Agricultural firm H.J. Baker announced that sales veteran Shi Dongshen has joined their Shanghai office in China. This newest hire follows the recent opening of their Lianyungang Sulphur Bentonite Plant. Read More
CropLife 100CHS Partners With Northern Partners Coop On Fertilizer …
January 21, 2015
In addition, the two companies will form a joint venture to build and operate a grain barge loading facility that will handle corn, soybeans and wheat for export through the CHS terminal at Myrtle Grove, LA. Read More
Matt Hopkins5 Bold Predictions For Ag Retail In 2015
January 21, 2015
This past year was filled with ups and downs for the nation’s top ag retailers, but what will 2015 have in store? Read More
SoftwareDeere Launches App Center
January 20, 2015
The John Deere App Center provides users the ability to search and find apps most useful to their business or operations. Read More
Crop InputsNew Syngenta Herbicide Approved In Soybeans, Sunflowers
January 20, 2015
Syngenta will sell BroadAxe XC herbicide in 2015 for use on soybeans, sunflowers and dry peas Read More
CropLife 100Wilbur-Ellis Move To Colorado Complete
January 20, 2015
Wilbur-Ellis Co. announces the opening of its new Agribusiness Division location in the Denver, CO, Metro Area. The new facility will host key personnel as the company shifts the base of its Agribusiness operations from California to Colorado. Read More
Crop InputsNovozymes Sales Figures Up For 2014
January 20, 2015
Novozymes announces its sales growth in 2014 was in line with expectations as sales grew by 7% compared with 2013. Read More
CropLife 100United Suppliers, McGregor Co., Five Others To Form Ali…
January 20, 2015
These companies will continue to operate as independently owned and operated businesses, however, their crop protection divisions will now be formally aligned under the umbrella of Aligned Ag Distributors. Read More
Eric SfiligojGMO Or DNA? LOL Or WTF?
January 19, 2015
A new survey finds the American public seems generally confused when it comes to any three-letter descriptor for their food. Read More
FertilizerAGROTAIN Wins No-Till Product Of The Year Again
January 19, 2015
This marks the 10th straight year AGROTAIN nitrogen stabilizer has been named the top product in this category; no other product has matched this honor Read More