Weather Prohibits Early Soil-Applied Herbicides

While recent rainy conditions have prevented farmers from using soil-applied herbicides, one Purdue Extension specialist reminds corn growers that many products can be applied post-emergence.

“Almost all chloroacetamide/atrazine premix products can be applied to emerged corn,” said weed scientist Bill Johnson.

But he also said growers need to take precautions to prevent plant injury.

“Atrazine and chloroacetamide injury is more common in cool, cloudy weather and wet soils because these conditions slow a corn plant’s ability to metabolize or detoxify herbicides,” Johnson said. “Corn will be stressed after coming through a cool, wet period and will be more susceptible to herbicide injury.”

Once corn has emerged, farmers should be careful not to apply chloroacetamide/atrazine premixes in nitrogen solutions. Most labels state that atrazine premixes should be applied only with water once corn has emerged.

“Nitrogen solutions are effective in promoting herbicide uptake and causing necrosis on leaves by themselves, resulting in the burning and yellowing injury we occasionally see,” Johnson said. “A few products do allow post-emergence applications in nitrogen solutions, but growers should consult the label if they have questions about a specific product.”

Tank-mixes of 2,4-D with chloroacetamide/atrazine premix applied post-emergence also can injure crops if applied improperly. Acetochlor (Harness, Surpass, Volley, and others) labels indicate that 2,4-D should not be applied within 7-14 days before or 3-5 days after planting, but it should be applied before crop emergence.

Johnson said applications within 7-14 days before planting can injure corn by being washed down into the corn seed germination zone, or seed furrow. Applications after planting can cause injury if the combination contacts corn foliage.

“If in doubt about the crop injury potential of a specific chloroacetamide/atrazine premix, consult the label to see if it is allowed, or do not tank-mix 2,4-D with chloroacetamide/atrazine premixes and apply to emerged corn,” he said.

Should farmers have fields where corn is yellow and stressed from cool, wet weather, they should wait a few days to allow corn to recover from cold stress before applying herbicides.

Treatments containing atrazine will control many small, emerged broadleaf weeds. But, according to Johnson, emerged grass weeds tend to be more of an issue.

“Atrazine has activity on emerged grasses, and it is most effective when applied at high rates to very small grasses,” he said. “Products containing rimsulfuron will provide some foliar residual control of grass weeds and can be mixed with either the atrazine premixes or with glyphosate or glufosinate in Roundup Ready or Liberty Link corn.

“Larger grasses will require the addition of post-emergence herbicides.”

For a table with a full list of corn products that have both some burndown capability and can be applied post-emergence, visit the Purdue Extension weed science Web site.

(Source: Indiana Ag Connection)

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

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
EquipmentNew Holland Acquires Miller-St. Nazianz
September 3, 2014
The assets of Miller acquired as part of the transaction will become part of New Holland Agriculture, a CNH Industrial brand, building on a successful four-year partnership between the two companies. Read More
CropLife 100Pinnacle Acquires East Kansas Chemical
September 2, 2014
Ranked 82nd on the CropLife 100, East Kansas Chemical will operate as part of Pinnacle's Performance Agriculture brand. 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
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

Latest News

CropLife 100Pinnacle Acquires Kansas-Based Cedar Ridge Supply
September 16, 2014
Cedar Ridge Supply will operate as part of Pinnacle's Performance Agriculture brand. Read More
StewardshipSecretary Vilsack Highlights Innovative Conservation Ef…
September 15, 2014
Nearly $16 million in Conservation Innovation Grants (CIGs) will be awarded to 47 organizations to help develop cutting-edge ideas to accelerate innovation in private lands conservation. Read More
Seed/BiotechSyngenta Responds To Cargill Lawsuit
September 15, 2014
Syngenta believes that the lawsuit is without merit and strongly upholds the right of growers to have access to approved new technologies. Read More
Equipment2014 Farm Science Review Launches Mobile App
September 15, 2014
Smartphone and tablet users planning on attending the 2014 Farm Science Review can now download this year’s customized mobile application. Read More
CropLife 100Southern States Coop Grower Sets Georgia Soybean Yield …
September 15, 2014
Georgia farmer Randy Dowdy's soybeans yielded an astonishing 110.66 bushels per acre, crushing the previous record of 82 bushels-per-acre. Read More
NIMITZ Treated vs Untreated pepper plant
InsecticidesNIMITZ Nematicide Approved By EPA
September 12, 2014
NIMITZ is a novel, non-fumigant nematicide with simplified application features, user safety and an active ingredient with a unique mode of action. Read More
InsecticidesMarrone Bio Innovations Receives Patent For Chromobacte…
September 11, 2014
The patent is the first step for MBI in developing a commercially viable product to inhibit infestations of corn rootworm larvae across America and other regions. Read More
HerbicidesDow AgroSciences: Keeping The Pipeline Stocked
September 11, 2014
Dow AgroSciences is embracing product diversity to drive the company’s future. Read More
CropLife 100CHS Is Official Partner Of New St. Paul Ballpark
September 10, 2014
The new ballpark in St. Paul, MN, officially became CHS Field with Twin Cities-based CHS Inc. revealed as the naming rights partner. Read More
EquipmentHagie Honors Farming Stewardship Leaders
September 10, 2014
The Iowa Farm Environmental Leader award recognizes Iowa farmers as environmental leaders that are committed to healthy soils and improved water quality. Read More
Precision AgPlantBeat: Your Plants’ Pulse In The Palm Of Your Han…
September 10, 2014
A new agronomic monitoring and recommendation service from Phytech could rewrite the book on real-time plant health status monitoring. Read More
StewardshipCCAs Making Headway With 4R Program In Lake Erie Wester…
September 9, 2014
Certified Crop Advisers are implementing the 4R Nutrient Stewardship Certification program in Lake Erie's Western Basin to improve water quality. Read More
MicronutrientsMicronutrients Going Macro
September 9, 2014
Between 2014’s fantastic growing conditions and a heightened awareness on plant nutrition, the major players in micronutrients are gearing up for another big year. Read More
Crop InputsFMC Announces Cheminova Takeover
September 8, 2014
FMC Corporation today announced that it has signed a definitive agreement to acquire Cheminova, a wholly owned subsidiary of Auriga Industries. Read More
HerbicidesValent’s Fierce XLT Herbicide Receives EPA Approv…
September 8, 2014
Valent U.S.A. Corp. announced today that Fierce XLT Soybean Herbicide is now federally registered for preemergence weed control in soybeans Read More
Eric SfiligojIndustry Consolidation Set To Increase Going Forward
September 8, 2014
As the agricultural marketplace moves into fall, one observer predicts the pace of consolidation will grow at all levels. Read More
LegislationCropLife America Leaders Address Regulatory Landscape, …
September 8, 2014
As CropLife America enters its 81st year, the organization’s leaders have seen another period of rapid and visible policy and public issue activity. 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