Pigweed Update: 4 Tips For Curtailing Palmer Amaranth Movement

The known distribution of Palmer amaranth in Illinois based on 2012–2013 surveys by university weed scientists.
The known distribution of Palmer amaranth in Illinois based on 2012–2013 surveys by university weed scientists.

Palmer amaranth (Amaranthus palmeri) has garnered much attention recently in both academic discussions and popular press releases, and with good reason. Among the weedy species of Amaranthus, Palmer amaranth has the fastest growth rate and is the most competitive with the crops common to Midwest agronomic cropping systems. Soybean yield losses approaching 80% and corn yield losses exceeding 90% have been reported in the peer-reviewed scientific literature, reports the University of Illinois-Extension’s Aaron Hager.

Palmer amaranth can be effectively managed in Illinois agronomic crops, but the greatest likelihood for successful management is with systems that employ multiple effective management tactics. Palmer amaranth is perhaps the personification of a weed species that requires an integrated management approach.

Unlike waterhemp, Palmer amaranth is not indigenous to Illinois. Palmer amaranth evolved as a desert-dwelling species in the southwestern United States, including areas of the Sonoran Desert. However, 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. The presence of Palmer amaranth in agricultural landscapes of the eastern United States is perceived by some to be only a recent phenomenon, but Dr. Jonathan Sauer, noted expert of Amaranthus taxonomy, noted in 1957 that, “It looks as if there has been recent and substantial northeastward expansion of A. palmeri resulting in its present wide area of cohabitation with interior species,” (Sauer 1957).

Will Palmer amaranth populations, likely introduced by seeds moved into Illinois from areas where Palmer amaranth has become the dominant pigweed species, be able to adapt to the landscape and growing conditions of Illinois? Perhaps a more important question is to define the damage niche of Palmer amaranth populations in Illinois agronomic cropping systems.

Recent research conducted in Illinois by Dr. Adam Davis, USDA-ARS plant ecologist at the University of Illinois, has examined these important questions. Results from these experiments have demonstrated that there are few landscape-level barriers to the establishment of Palmer amaranth populations in Illinois, and that these populations, once established, are competitive with crop species. In other words, these results indicate that it’s not a question of if Palmer amaranth will become established in Illinois, but rather when and where it will become established.

Similar to female waterhemp plants, female Palmer amaranth plants produce an abundance of seeds. These small black seeds are easily moved within and between fields in myriad ways, including harvesting and tillage equipment. If you identify Palmer amaranth in one or more fields, what can you do this fall to limit movement of the seed?

The following four suggestions were developed by weed scientists in Illinois to help curtail the movement of Palmer amaranth seed:

  1. Fields with Palmer amaranth populations should be the last fields harvested this fall and the last fields planted next spring.
  2. Mark or flag areas where Palmer amaranth plants have produced seed. These areas should be intensively scouted the following season and an aggressive Palmer amaranth management plan implemented to prevent future seed production.
  3. Do not mechanically harvest mature Palmer amaranth plants with crop harvesting equipment. Physically remove the plants immediately prior to harvest and either leave the plants in the field or place in a sturdy garden bag and remove the plants from the field. Bury or burn the bags in a burn barrel as soon as possible.
  4. Fields in which Palmer amaranth seeds were produced should NOT be tilled during the fall or following spring. Leaving the seeds near the soil surface increases the opportunities for seed predation by various granivores.

It’s not too early to begin planning an integrated Palmer amaranth management program. An integrated herbicide program should include soil-residual herbicides applied at full recommended use rates within two weeks of planting and followed by postemergence herbicides applied before Palmer amaranth plants exceed 3 inches tall. Most herbicides that control waterhemp also control Palmer amaranth, but successful, long-term management of Palmer amaranth in Illinois will likely require more than herbicides.

SOURCE: Aaron Hager, University Of Illinois-Extension, The Bulletin

Topics:

Leave a Reply

Crop Inputs 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
Seed/BiotechSyngenta Delivers Two New Winter Wheat Varieties To Eastern Corn Belt
August 6, 2014
Adding to its portfolio of AgriPro brand wheat varieties, Syngenta introduces SY 007 and SY 474 soft red winter wheat varieties. Read More
Aerial view of the West Fertilizer explosion site
FertilizerFertilizer Companies Blame City For West, TX, Explosion
August 6, 2014
El Dorado Chemical Co. and CF Industries contend the city failed to properly train the first responders and had insufficient protocols in place to battle the April 17, 2013, blaze at West Fertilizer Co. that triggered the explosion. Read More
FungicidesResearchers Target Soybean Disease With Genetic Resistance Study
August 6, 2014
University of Illinois researchers will share new information on controlling sudden death syndrome through genetic resistance at this year's Agronomy Day. Read More

Trending Articles

ManagementExpert To Discuss Farmland Value, Rent At Farm Science Review
August 18, 2014
While cropland values in Ohio increased in the past two years, they have remained flat in 2014, declining in some cases, according to an Ohio State University agricultural economist. Read More
EquipmentAdvance Your Technology IQ At MAGIE
August 13, 2014
The Midwest AG Industries Exposition (August 20-21) is the place you need to be to see, study and evaluate how new advances in the equipment, operations, crop protection and fertility sectors can help your business prosper. Read More
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
StewardshipMichigan Agriculture Leaders On Toledo Water Ban: We Want To Be Part Of The Conversation
August 8, 2014
Leaders of Michigan agricultural organizations said Thursday that the government should not have a “knee-jerk reaction” based on last weekend’s water ban in Toledo due to fertilizer run-off in Lake Erie. Read More
CropLife 100BRANDT Acquires Lemon Ag Services
August 4, 2014
The acquisition of Lemon Ag fits BRANDT’s aggressive corporate strategy of providing superior agronomic advice and services for customers in central Illinois. Read More
Eric SfiligojThe Resurgence Of Crop Protection
August 4, 2014
Plenty of new offerings over the next few years should see a rebirth for the crop protection products category in terms of market share. Read More

Latest News

InsecticidesBioinsecticide VENERATE Now Registered In California
August 27, 2014
Marrone Bio Innovations' VENERATE is a new tool to help California growers control crop-damaging insect pests, fight the development of insect resistance and reduce pesticide residues on fruits and vegetables. Read More
CropLife 100Two Iowa-Based Ag Co-ops To Merge
August 27, 2014
The Board of Directors and management of United Western Coop, Missouri Valley, IA has completed a merger with Heartland Co-op, West Des Moines, IA, effective September 1, 2014. Read More
FertilizerKoch Expands AGROTAIN Nitrogen Stabilizer Portfolio
August 26, 2014
Koch Agronomic Services, LLC has added two new innovative nitrogen stabilizers to the AGROTAIN product family – AGROTAIN ADVANCED and AGROTAIN DRI-­MAXX. Read More
Seed/BiotechDuPont To Build Two Seed Treatment Centers
August 26, 2014
DuPont has announced construction on two state-of-the-art centers dedicated to developing and testing seed treatment formulations, applications and seed handling techniques in an important step toward bringing new solutions to growers. Read More
Seed/BiotechLoveland Products Acquires A Controlling Interest In Ag…
August 26, 2014
Loveland Products, a subsidiary of Agrium , has announced the company has acquired a controlling interest in Agricen, a Dallas-area agricultural biotechnology company delivering biochemical-based products for efficient and sustainable plant nutrition. Read More
StewardshipUp Close Look At The 2014 Environmental Respect Award W…
August 25, 2014
The 2014 Environmental Respect Award winners were honored recently at the 24th annual event in Wilmington, DE. Read More
Eric SfiligojAg Science Rejection Carries Consequences
August 25, 2014
As innuendo and fear dog the regulatory process, agriculture can’t get the new tools it needs to combat world hunger. Read More
LegislationFarmers Dismayed As New Farm Bill Dumps Direct Payments
August 25, 2014
The threatened end of cash subsidies to the nation’s row crop farmers dates back through at least the last two iterations of national agriculture policy legislation. Read More
MAGIE 2014 ShowStopper
EquipmentJohn Deere Again Wins MAGIE ShowStopper Award
August 25, 2014
For the second consecutive year, John Deere was honored at the Midwest AG Industries Exposition (MAGIE) for its new R4045 sprayer. Read More
CropLife 100GROWMARK CEO To Retire
August 22, 2014
GROWMARK chief executive officer Jeff Solberg has announced his retirement effective September 15, 2014. Read More
InsecticidesDuPont’s Prevathon Approved For Dry Beans
August 22, 2014
DuPont Prevathon insect control powered by Rynaxypyr has received EPA registration for foliar use on dry bean crops, including dried shelled peas and beans. Read More
ManagementNCGA DuPont New Leaders Program Enters Sophmore Season
August 20, 2014
The National Corn Growers Association and DuPont are pleased to announce the second year of the NCGA DuPont New Leaders Program. Read More
FungicidesVerdesian Links Up With Mitsui, Hokusan
August 20, 2014
Mitsui Chemicals Agro, Inc., and Hokusan Co., announced the signing of an exclusive licensing agreement allowing Verdesian Life Sciences global access to its patented technology for suppressing mycotoxin contamination in wheat and barley. Read More
SprayersUniversity Of Illinois Introduces New Spray App
August 18, 2014
University of Illinois Extension has released a new smartphone app for making sprayer-related calculations. Pesticide Spray Calculator, or Spray Calc, Read More
Crop InputsSyngenta Names New Manager Of Federal Government Relati…
August 18, 2014
Laura Wood Peterson has joined Syngenta as manager of federal government relations, based in Washington, DC. Read More
ManagementExpert To Discuss Farmland Value, Rent At Farm Science …
August 18, 2014
While cropland values in Ohio increased in the past two years, they have remained flat in 2014, declining in some cases, according to an Ohio State University agricultural economist. Read More
EquipmentDeere Announces Factory Layoffs
August 18, 2014
Deere & Co. has announced it will reduce the size of its manufacturing workforce at some agricultural equipment factories in response to current market demand for its products. Read More
HerbicidesNew DuPont Afforia Herbicide Gives Crops A Clean Start
August 18, 2014
DuPont Afforia is a preplant herbicide for soybeans and other field crops that provides excellent burndown and residual control of many challenging weeds, such as marestail and waterhemp. Read More