Controlling Marestail After Crop Emergence

Glyphosate-Resistant MarestailOver the past several days, growers have increasingly been looking for options to control marestail (horseweed) after crop emergence, said University of Illinois associate professor of weed sciences Aaron Hager.

“Many have reported poor marestail control from herbicides applied prior to planting (primarily no-till soybean), especially when these burndown applications contained only glyphosate or glyphosate and 2,4-D,” Hager said. “The increasing frequency of glyphosate-resistant marestail populations, the rush to plant whenever field conditions were conducive, and the less-than-ideal environmental conditions when many burndown applications were made, have contributed to a challenging situation for which a good solution might not be available.”

Hager added that while several herbicides can control emerged marestail plants that are less than 6 inches tall, few herbicides will control plants that are 12 inches or taller.

“The majority of Illinois corn acres receive one or more tillage operations prior to planting, and these tillage operations generally control emerged marestail. However, marestail might be a problem in corn acres planted with limited or no preplant tillage,” he explained. “Growth regulator herbicides, such as dicamba and 2,4-D, can provide control or suppression of emerged marestail. Some acetolactate synthase (ALS)-inhibiting herbicides also have activity against marestail, and control is sometimes improved when — if allowed by label — these herbicides are tank-mixed with dicamba or 2,4-D.”

Another option for control is glufosinate applied alone or with atrazine in glufosinate-resistant corn hybrids. “Keep in mind that if glufosinate was applied as a burndown treatment prior to corn planting, no in-crop applications of glufosinate can be made,” he cautioned.

Foliar-applied hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors combined with atrazine are other options that can provide control/suppression of emerged marestail less than about 6 inches tall, Hager added.

“Marestail that survived a burndown herbicide in no-till soybean can be very difficult to control after soybean have emerged. Cloransulam or chlorimuron-containing products can be applied postemergence to suppress or control emerged marestail,” he said. “These products should be applied after the first soybean trifoliolate has expanded and before marestail height exceeds 6 inches.

“These products can be tank-mixed with glyphosate for postemergence applications in glyphosate-resistant soybean. Glyphosate is an option for control of glyphosate-sensitive biotypes and glufosinate is an effective option when used in glufosinate-resistant (Liberty Link) soybean varieties,” he explained. “Foliar-applied protoporphyrinogen oxidase (PPO)-inhibiting herbicides will not control emerged marestail.”

Hager added that another option to consider is to physically remove the surviving plants with a hoe, weed hook, or by pulling them from the soil.

“Before summarily dismissing this as a viable option, remember that marestail plants can be very competitive with soybean and can produce around 200,000 seeds per plant that are easily dispersed long distances by wind,” he said. “A few plants that reach maturity this year can produce a sufficient amount of seed to infest an entire field within only a couple of seasons. Removing surviving marestail plants before they produce seed could save a great deal of time, money, and consternation in future seasons.”

Topics:

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

Trending Articles

Crop InputsPlatform Specialty Products To Acquire Arysta LifeScience
October 20, 2014
Once the acquisition is complete, Platform Specialty Products will combine Arysta LifeScience with previously acquired companies Agriphar and Chemtura Crop Solutions. Read More
Seed/BiotechMonsanto Offers New Support For Ferguson, Area Communities
October 8, 2014
Monsanto Co. has committed $1 million in new support for several collaborative efforts in Ferguson, MO, and surrounding communities in North St. Louis County. Read More
Seed/BiotechUnapproved Genetically Modified Wheat Found In Montana
October 3, 2014
USDA reports that one year after discovery of Monsanto's unapproved wheat in a single Oregon field disrupted U.S. wheat export sales, the GMO wheat has again been found in Montana. Read More
Equipment2014 Product Of The Year Voting
September 19, 2014
The deadline to vote for the 2014 CropLife IRON Product of the Year is October 31. Please cast your vote today to help us determine the winner. Read More
FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
CropLife 100CHS To Build $3 Billion Fertilizer Plant In North Dakota
September 5, 2014
The fertilizer plant in Spiritwood will be the single largest investment in CHS history, as well as the single largest private investment project ever undertaken in North Dakota. Read More

Latest News

InsecticidesValent U.S.A., MGK Form Marketing Agreement
October 24, 2014
Valent has formed an agreement with Minneapolis-based MGK to manage the marketing and sales of MGK’s crop protection line of insect control products within the U.S. beginning April 1, 2015. Read More
StewardshipFlorida’s 4R Advocate Keeps Improving
October 24, 2014
Florida farmer Alan Jones uses the 4R principles of nutrient stewardship as the core of his fertility program, which allows him to maximize production and keep costs in check. Read More
Seed/BiotechMonsanto Named One Of The World’s Best Multinational …
October 23, 2014
Monsanto ranked No. 8 in the world’s largest annual study of workplace excellence that identifies the top 25 best multinational companies in terms of workplace culture. Read More
Crop InputsArysta Hires Former Agri-Chem, CPS Employee For Delta S…
October 23, 2014
New Territory Sales Manager Mark Peel’s primary role will focus on working with growers regarding fungicides in Louisiana, Mississippi, Arkansas and Tennessee. Read More
CropLife 100GROWMARK Announces Appointments In Plant Food Division
October 22, 2014
GROWMARK, Inc. has announced the three key staff changes in its Plant Food Division. Read More
CropLife 100GROWMARK Appoints New VP Of Finance And Risk Management
October 22, 2014
Wade Mittelstadt has been named GROWMARK Vice President, Financial and Risk Mangement, effective December 1, 2014. Read More
FungicidesEPA Approves BASF In-Furrow Corn Fungicide
October 22, 2014
Field trials show Xanthion In-furrow fungicide provides more rapid emergence, extended residual control and improved seedling health than untreated crops. Read More
EquipmentAgraScout App Available At No Cost To Universities
October 21, 2014
AgraScout, a fast and easy to use mobile crop scouting app, is now available at no cost to University students, Read More
LegislationNew Farm Bill Program To Provide Relief To Farmers Affe…
October 21, 2014
The USDA has implemented a new Farm Bill initiative that will provide relief to farmers affected by severe weather, including drought. Read More
ManagementGreenfield Scholars Program Aims To Sustain Agronomy Wo…
October 21, 2014
The program encourages talented students to study agronomy, crop and soil sciences while cultivating networks to develop the necessary workforce to sustain the profession. Read More
Paul SchrimpfPrecision Ag: Taking It To The Hill
October 21, 2014
A new coalition took the good news message of precision agriculture to Washington, DC, last month. Read More
ManagementUSDA Awards $18 Million In Small Business Research Gran…
October 21, 2014
The grants will provide high quality, advanced research and development that will lead to technological innovations and solutions for American agriculture. Read More
FertilizerCF Industries Terminates Merger Discussions With Yara I…
October 21, 2014
CF Industries Holdings and Yara International have terminated their discussions regarding a potential merger of equals transaction. Read More
Seed/BiotechSyngenta Ranked A Top 10 Biotech Employer For Third tim…
October 20, 2014
Syngenta ranked in the top 10 among the world’s top biotech employers, according to an annual survey conducted by Science magazine. Read More
CropLife 100Wheat Growers Break Ground For New Facility At Kennebec
October 20, 2014
Wheat Growers has broke ground for a state-of-the-art shuttle loader grain handling, fertilizer and agronomy facility in Kennebec, SD. Read More
FertilizerVerdesian Life Sciences Signs Agreement With Los Alamos…
October 20, 2014
Verdesian Life Sciences has signed a licensing agreement with Los Alamos National Laboratory to develop and market LANL’s latest nitrogen enhancement technology for plants. Read More
MicronutrientsStoller Group Announces Groundbreaking At New Office Bu…
October 20, 2014
Jerry Stoller, founder and president of Stoller Group, announced the groundbreaking at the site of the company’s future headquarters in Read More
Crop InputsBioSafe Systems Opens New Production Facility In Nevada
October 20, 2014
BioSafe Systems has completed construction of a state-of-art production facility in Sparks, NV, for its line of activated peroxygen products. Read More