Weed Worries Worsening

Giant Ragweed

According to most researchers, finding herbicide-resistant weeds is becoming easier with each passing year. “There has been a steady increase in weeds resistant to some of our best herbicides since 1999,” says Dave Stoltenberg, professor at the Department of Agronomy for the University of Wisconsin-Madison. “Our studies found that there was 0% of giant ragweed showing resistance in 1999. In 2005, this number increased to 23%.”

In fact, giant ragweed could be the weed to watch in 2007. By most accounts, the presence of giant ragweed in crop fields can lead to yield losses of 45% to 70% in soybeans and 10% in corn, primarily because of its ability to grow up to 1 inch per day during its peak growth stage.

“Giant ragweed has a number of characteristics that make it a ‘great’ weed, and inherently difficult to control,” says Mark Loux, professor and Extension specialist for the Department of Horticulture and Crop Science at The Ohio State University. “It emerges from late March through early July in Ohio, and management programs need to address this long period of emergence,”

Since giant ragweed is usually present in fields at planting, it should be controlled using a combination of preemergence and postemergence herbicides. In soybeans, this should include a preplant burndown herbicide treatment using 2,4-D ester plus either glyphosate or paraquat. Next, in fields with a history of giant ragweed control problems, post applications should utilize either glyphosate, fomesafen, lactofen, or cloransulam-methyl. In fields with a history of general weed control problems, this should be followed up by a second post application of glyphosate approximately three weeks later. With corn, a similar multiple herbicide approach should be used.

Other Weeds To Watch

With more continuous corn being projected for 2007, researchers predict that tall waterhemp will become more of a problem. According to John Long, district agronomist for Mycogen Seeds, this weed also is developing a tendency to emerge later during the growing season.

To combat this, Long suggests retailers conduct a thorough scouting of fields to determine how severe a tall waterhemp outbreak there might be. Once this is established, applying a half rate of preemergence herbicide is advised.

Topics:

Leave a Reply

Herbicides Stories

Crop InputsMonsanto, FMC Expand Roundup Ready PLUS Platform
August 31, 2015
FMC Corp. and Monsanto Co. announced today an expanded agreement to continue their participation in the Roundup Ready PLUS Crop Read More
HerbicidesREUTERS: Anti-GMO ‘Scientist’ Calls For New Review Of Glyphosate
August 20, 2015
EDITORS NOTE: We feel that it is important to note that there are those that believe one of the lead Read More
Mature Waterhemp in Corn
HerbicidesAustralia’s Seed Destructor Could Be Midwest’s New Tool Against Weed Resistance
August 17, 2015
It’s a piece of equipment that probably isn’t on many Midwest farmers’ radars at this time, but could eventually be Read More
HerbicidesExpert: IARC Herbicide Classifications Leading To Confusion, Misinformation
July 24, 2015
Few people in the crop protection industry had heard of the International Agency for Research on Cancer (IARC) before this Read More
Top 100 Articles
Crop InputsLand ‘O Lakes, United Suppliers Finalize Merger
August 24, 2015
According to a press release on August 24, owners of United Suppliers, Inc. and members of Land O’Lakes, Inc. “have Read More
West Central Cooperative, Jefferson, IA
CropLife 100Iowa Cooperatives To Explore Unification
August 19, 2015
The boards of directors at two of Iowa’s leading farmer-owned cooperatives yesterday signed a letter of intent to study the Read More
CropLife 100Southern States Coop Hosting Drone Flight This Friday
August 3, 2015
Southern States Cooperative — No. 9 on the CropLife 100 — is hosting an FAA-approved drone demonstration at Grandview Farms Read More
CropLife 100Aligned Ag Distributors Adds Four New Owners
July 30, 2015
Aligned Ag Distributors LLC has announced the addition of four new customer/owners to Franklin Holding Co. LLC. They are: The Read More
CropLife 100Pinnacle Purchases California-Based Specialty Crops Retailer
July 20, 2015
Pinnacle Agriculture Holdings has successfully acquired California-based NH3 Service Co.  Operating as part of Pinnacle’s Performance Agriculture brand, the new locations Read More
Asmus Farm Supply liquid fertilizer facility features 20,000 square feet
CropLife 100Slideshow: Asmus Farm Supply Shows Off Its New Liquid Fertilizer Facility
July 15, 2015
Asmus Farm Supply, Rake, IA, recently added a new liquid fertilizer facility to its company operations. The new liquid fertilizer Read More
Latest News
Crop InputsBayer CropScience: A Decade Of Innovation
September 3, 2015
BLAMS! It’s not a sound effect from the pages of a Superhero comic book. Instead this nifty acronym is used Read More
ManagementReviewing MAGIE 2015
September 2, 2015
CropLife Editor Eric Sfiligoj talks what he saw at the recent Midwest AG Industries Exposition (MAGIE) show. Read More
Melissa Olds Dow AgroSciences
Crop InputsDow AgroSciences: Highlighting The Past, Present & …
September 2, 2015
In general, media events held by large agricultural suppliers tend to focus primarily on what plans the company has in Read More
Mobile tablet
OpinionTaking Data Head On
September 2, 2015
As you read this column, I’m hoping that if you picked up the phone and gave me a call, you’d Read More
Young soybean field
Industry NewsArysta LifeScience Announces New Business Unit Head For…
September 1, 2015
Arysta LifeScience North America announces the addition of Rico Christensen, Business Unit Head, North America. Christensen will have responsibility for Read More
Wilbur Ellis Pink Soybean Seed Treatment
Crop InputsWilbur-Ellis Goes Pink With Soybean Seed Treatments For…
September 1, 2015
This past year, proceeds of pink-dyed soybeans treated and sold to Wilbur-Ellis seed customers in Chester, SD, went to two Read More
SprayersNORAC Active Wing Roll Slated For More Sprayers
September 1, 2015
NORAC Systems, a member of the Topcon Positioning Group, announces the release of Active Wing Roll for RoGator, Apache, New Read More
Syngenta Sign
FungicidesSyngenta’s Newest Fungicide Receives EPA Approval
September 1, 2015
Syngenta announced today that its newest succinate dehydrogenase inhibitor (SDHI) fungicide – Solatenol – has received registration from EPA and Read More
Flooded corn in Indiana
Crop InputsDelaying The Fertilizer Decision
September 1, 2015
Comments gathered from several retailers recently evidenced a classic good-news-bad-news scenario. Good news is prices and supplies of nitrogen, phosphate, Read More
StewardshipBee Buffer Strip Initiative Seeks 100 Ohio Farmers
August 31, 2015
The U.S. Bee Buffer Project, an initiative of the Pollinator Partnership (P2), Burt’s Bees and The Burt’s Bees Greater Good Read More
2015 ShowStopper Award, MAGIE
EquipmentA ShowStopper From Case IH: The Patriot 2250
August 31, 2015
For nine years now, visitors to the yearly Midwest AG Industries Exposition (MAGIE) show have been tasked with not only Read More
Crop InputsMonsanto, FMC Expand Roundup Ready PLUS Platform
August 31, 2015
FMC Corp. and Monsanto Co. announced today an expanded agreement to continue their participation in the Roundup Ready PLUS Crop Read More
Deere Nutrient Applicator
Eric SfiligojThe Good & Bad News From MAGIE
August 31, 2015
As I write this column, I’ve just returned from the annual Midwest AG Industries (MAGIE) trade show in Bloomington, IL. Read More
CPS Morenci receiving its 4R certification
StewardshipCPS Morenci Becomes First Michigan Facility Certified I…
August 31, 2015
The 4R Nutrient Stewardship Certification Program has announced that Crop Production Services, Inc.’s facility located in Morenci, MI, has been Read More
EquipmentDeere Announces Soucy Track Distribution Alliance
August 28, 2015
John Deere announces an alliance with Soucy Track to sell and distribute products through the John Deere dealer channel. “This Read More
FertilizerFall-Applied Phosphorus: A Rooted Investment
August 28, 2015
As commodity prices decrease and input prices continue to rise, farmers are seeking more efficient strategies for meeting a high Read More
Monsanto Sign
Crop InputsWhat’s Next For Monsanto, Syngenta?
August 28, 2015
After dropping its $47 billion bid to take over Swiss agribusiness firm Syngenta, Monsanto may be turning its focus to Read More
Golden Harvest Corn stalks
Crop InputsMonsanto: Syngenta Not The Only Horse In Crop Protectio…
August 28, 2015
Monsanto Co, having ditched an audacious $46 billion (£30 billion) offer for Syngenta AG, may downshift to a humbler strategy Read More