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University of Illinois Extension serving Christian, Jersey, Macoupin and Montgomery Counties

Montgomery County
#1 Industrial Park Dr.
Hillsboro, IL 62049
Phone: 217-532-3941
FAX: 217-532-3944
Email: uie-cjmm@illinois.edu
Hours: Monday - Friday 8 am to 12 pm, 1 pm to 4:30 pm

Christian County
1120 N Webster St.
Taylorville, IL 62568
Phone: 217-287-7246
FAX: 217-287-7248
Hours: Monday - Friday 8am to 11:30am, 12:30pm to 4.30pm

Jersey County
201 W. Exchange St.
Suite A
Jerseyville, IL 62052
Phone: 618-498-2913
FAX: 618-498-5913
Hours: Tuesday & Wednesday 8 am to 12 pm and 1 pm to 4:30 pm and Thursday 8 am to 12 pm

Macoupin County
#60 Carlinville Plaza
Carlinville, IL 62626
Phone: 217-854-9604
FAX: 217-854-7804
Hours: Monday - Thursday 8 am to 12 pm; 1 pm to 4:30 pm

News Release

Palmer amaranth could affect Illinois soybean yield

Source: Adam Davis, 217-333-9654, asdavis1@illinois.edu

News writer: Lauren Quinn, 217-300-2435, ldquinn@illinois.edu

 

·        Palmer amaranth, a major weed in southern soybean cropping systems, is able to complete its life cycle and affect soybean yield in Illinois.

·        Although Palmer amaranth currently exists at low levels in Illinois, it is capable of causing greater economic damage if continued seed introductions and mismanagement occur.  

·        Farmers should learn to identify Palmer amaranth at the seedling stage and be aggressive in removing it from fields and equipment.

URBANA, Ill. – Although agricultural weed Palmer amaranth (Amaranthus palmeri) primarily impacts southern U.S. states, new research shows it could soon spread further north and damage soybean yields in Illinois.

 

“We did a common garden study in southern, central, and northern Illinois to ask if different varieties of Palmer amaranth from the south complete their life cycle in all three locations and cause yield loss in soybean. The short answer is yes: there are no current climate limitations to any of the genotypes that we looked at,” said University of Illinois weed ecologist Adam Davis. “This is a serious weed.”

 

Illinois farmers are well acquainted with its aggressive cousin, tall waterhemp (Amaranthus tuberculatus), significant infestations of which can cause soybean yield losses of up to 30 percent. Palmer amaranth is an even bigger threat, causing soybean yield losses up to 80 percent in severe cases.

 

“It’s a real economic game-changer,” Davis noted. In the study, Davis and his colleagues only allowed Palmer amaranth to compete with soybean for five weeks to avoid seed dispersal and local infestation after the plants had reached maturity. Still, in that time, soybean yield loss reached 30 percent in some locations.

 

Unfortunately, Palmer amaranth does not conform to experimental rules in the field.

 

“It can complete its life cycle in a very short period of time. Even if you killed early season populations, if it comes up again in late summer, it can still produce seed by harvest time.”

 

Palmer amaranth already exists in Illinois, but it hasn’t become a major problem. “The short take-home message from this research is that Palmer amaranth is mainly seed limited in Illinois,” meaning the reason it’s not here in greater numbers is simply that not enough seeds have been introduced yet.

 

To avoid population explosion in Illinois and elsewhere, farmers should learn to identify and remove Palmer amaranth before it goes to seed. Davis also urges farmers to buy certified seed, including cover crop seed and meals, and to be careful about cleaning equipment, especially if it has been purchased out of state. He also suggests diversifying cropping systems to include winter annuals. Additional guidelines for identification and management of Palmer amaranth are published by the University of Illinois Weed Science Extension service.

 

"Palmer amaranth (Amaranthus palmeri) damage niche in Illinois soybean is seed limited," appears in Weed Science. The paper was co-authored by Aaron Hager from the U of I, Brian Schutte from New Mexico State University, and Bryan Young from Purdue University. Funding was provided by the USDA Agricultural Research Service and the Illinois Soybean Association.

 

The article is available online at http://www.bioone.org/doi/abs/10.1614/WS-D-14-00177.1.

 

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Local Contact: Gary Letterly, Extension Educator, Energy and Environmental Stewardship, letterly@illinois.edu