Timing, Product Choice Important For Postemergence Herbicide Applications

Weather has prevented Indiana corn farmers from applying herbicides before much of the crop emerged from the ground. But that doesn’t mean it’s too late, a pair of Purdue Extension weed scientists say.

Most of Indiana’s corn crop was planted May 4-9, but windy conditions followed by days of rain kept growers from applying pre-emergence herbicides for weed control. The good news, however, is that many of these herbicides are still safe for farmers to use after corn has emerged so long as they pay close attention to product selection and application timing, Bill Johnson and Travis Legleiter said.

“Many of the pre-emerge herbicides can also be applied post-emerge, and there are many herbicides for postemergence weed control in corn,” Johnson said. “The large number of products is a positive when considering glyphosate-resistance management and prevention, but they can also make timing and product application decisions more complicated.”

This is especially true because postemergence herbicides can affect corn ear development if those products are applied too late in the growing season.

When growers decide on herbicide products, Legleiter said they should consider weed species present, weed height and crop growth stage.

“The majority of conventional post-applied corn herbicides are effective on select weed species and only at certain weed heights,” he said. “Typically, a combination of products or a prepackage of active ingredients is needed to achieve control of all weed species present.”

Herbicide labels are a valuable resource for growers because they list which weed species the products control and recommended application heights.

Another resource is the Indiana and Ohio Weed Control Guide, published by Purdue Extension and Ohio State University Extension. The guide is available for free download from Purdue Extension’s The Education Store and searching for product code WS-15-W.

In addition to product choice and application timing as it relates to weed height, Johnson said it’s extremely important for growers to consider the growth stage and height of corn at the time of herbicide application to prevent injury.

“The type and amount of injury from an application beyond the labeled window is dependent upon the herbicide, other environmental stresses and the exact timing of application,” he said.

Injury symptoms can include ear pinching, ear bottlenecking, internode stacking, onion leafing, rat tailing, brace root malformation and green snap.

  • Johnson and Legleiter also offered a list of helpful tips for avoiding herbicide crop injury:
  • Don’t use contact herbicides right before rain or when there is heavy dew in order to avoid washing the herbicide down into the corn whorl.
  • Don’t apply growth regulator herbicides after several nights with temperatures 45 degrees Fahrenheit or cooler.
  • Don’t use UAN solutions as the herbicide carrier when applying atrazine premixes to spike-stage corn.
  • Don’t mix growth regulator herbicides with chloroacetamide herbicides and apply postemergence.
  • Don’t apply ALS inhibitors past the V6 growth stage in corn.
Topics:

Leave a Reply

Crop Inputs Stories

Giant Ragweed
HerbicidesSurvey Provides Insights On Giant Ragweed In The Corn Belt
May 2, 2016
A new survey published in the journal Weed Science offers insights into the distribution and management of giant ragweed, a Read More
Truck dumping dry fertilizer
FertilizerFertilizer Logistics Q&A: Southern States’ Joe Wlodkoski
May 2, 2016
Joe Wlodkoski, Director of Agronomy Procurement, Fertilizer, Southern States Cooperative, is a 40-plus year fertilizer industry veteran. He is quite Read More
West Central Dome structure
FertilizerFertilizer Logistics 2016: All Clear, So Far
May 1, 2016
After a relatively hairy early start to the spring fertilizer movement season with flooding in Louisiana and St. Louis, things Read More
MicronutrientsCharah Add Three Warehouses For SUL4R-PLUS Fertilizer
April 28, 2016
Charah, Inc., a total solutions company providing unparalleled service and innovation for the coal-fired power generation industry, announced today that Read More
Trending Articles
Eric SfiligojMissing The Family Ties In Agriculture
April 25, 2016
By its nature, the agriculture market is cyclical. Up and down cycles come and go with a regular pattern. For Read More
HerbicidesHerbicide Resistance In Waterhemp Continues To Grow
April 22, 2016
Twenty-five years ago, waterhemp was virtually unknown to Illinois farmers. Today, the broadleaf weed blankets corn and soybean fields across Read More
Eric SfiligojBiotech Corn Drop More Economics Vs. Consumer Rejection
April 18, 2016
Since their introduction into the agricultural marketplace, biotech crops has steadily grown in acreage in the countries of the world Read More
Crop InputsBayer: 5 Reasons We Disagree With Maryland Neonic Ban
April 12, 2016
We’re disappointed that the Maryland legislature chose not to stand up for sound science and the rights of Maryland’s homeowners Read More
Corn
OpinionChallenging Global Economic Conditions Putting More Heat On U.S. Ag Retailers
April 7, 2016
There it is. That vague, slightly sickening feeling in the pit of my stomach. Things are getting weird out there. Read More
ScoutPro iPad
Precision AgWhat’s Trending In Soil Testing And Scouting
April 6, 2016
Keeping up on soil testing and scouting, especially following unusual weather conditions, can play a role in maximizing yields. Soil Read More
Latest News
Giant Ragweed
HerbicidesSurvey Provides Insights On Giant Ragweed In The Corn B…
May 2, 2016
A new survey published in the journal Weed Science offers insights into the distribution and management of giant ragweed, a Read More
Truck dumping dry fertilizer
FertilizerFertilizer Logistics Q&A: Southern States’ Joe Wlod…
May 2, 2016
Joe Wlodkoski, Director of Agronomy Procurement, Fertilizer, Southern States Cooperative, is a 40-plus year fertilizer industry veteran. He is quite Read More
Eric SfiligojReasons For Hope In Commodity Prices
May 2, 2016
For many months now, the doomsayers have ruled the day in agriculture. Too much supply with too little demand would Read More
West Central Dome structure
FertilizerFertilizer Logistics 2016: All Clear, So Far
May 1, 2016
After a relatively hairy early start to the spring fertilizer movement season with flooding in Louisiana and St. Louis, things Read More
BAICOR
CropLife 100BRANDT Acquires Utah Specialty Fertilizer Company
April 28, 2016
BRANDT, a leading agriculture retailer and manufacturer of specialty ag products, has acquired a majority interest in BAICOR, L.C. BAICOR, Read More
Soybean field
Industry NewsVerdesian Life Sciences Adds Vice President Of Business…
April 28, 2016
Verdesian Life Sciences has announced the addition of Marc Treurniet to the plant health and nutrition company’s management team. Treurniet Read More
ManagementBiotech Crops Developments and Millennials
April 28, 2016
Editors Eric Sfiligoj and Paul Schrimpf talk about the latest activities in biotech crops and a major shift in the Read More
Industry NewsNachurs-Alpine, Pathway Biologic Extend Marketing Agree…
April 28, 2016
Nachurs-Alpine Solutions (Marion, OH) and Pathway Biologic (Plant City, FL) announce an extension to their exclusive marketing agreement specific to Read More
MicronutrientsCharah Add Three Warehouses For SUL4R-PLUS Fertilizer
April 28, 2016
Charah, Inc., a total solutions company providing unparalleled service and innovation for the coal-fired power generation industry, announced today that Read More
Spenser Forgey, Yahama Fortix
FungicidesIndiana Farmer Wins Arysta LifeScience FORTIX Fungicide…
April 28, 2016
Arysta LifeScience North America recently presented Spenser Forgey, a grower from Young America, IN, with a new 2016 Yamaha Grizzly Read More
Corn Field
HerbicidesNew Wilbur‐Ellis Herbicide Targets Volunteer Corn
April 28, 2016
Wilbur‐Ellis Co., a recognized leader in marketing and distribution of crop protection products, as well as precision agriculture technology, has Read More
StewardshipNRCS To Help Farmers Measure Conservation Impacts On Wa…
April 27, 2016
The USDA has announced the availability of $2 million to help farmers install edge-of-field stations that monitor water quality as Read More
Planter in Iowa
EquipmentTop 10 Twitter Pics For #Plant16
April 27, 2016
Despite some wet weather in parts of the Midwest, growers and ag retailers are working feverishly to plant this year’s Read More
HerbicidesHELM AGRO Launches New HELM Sulfentrazone 4F Herbicide
April 26, 2016
HELM AGRO US, Inc. has announced the federal Section 3 registration of its new HELM Sulfentrazone 4F herbicide. Classified as a Read More
Valley Irrigation Valley 8000 series on corn
EquipmentValley Irrigation Receives Environmental Stewardship Ho…
April 26, 2016
Valley Irrigation has been recognized as a Groundwater Guardian Green Site by the Groundwater Foundation. The Groundwater Guardian Green Site Read More
Eric SfiligojMissing The Family Ties In Agriculture
April 25, 2016
By its nature, the agriculture market is cyclical. Up and down cycles come and go with a regular pattern. For Read More
HerbicidesHerbicide Resistance In Waterhemp Continues To Grow
April 22, 2016
Twenty-five years ago, waterhemp was virtually unknown to Illinois farmers. Today, the broadleaf weed blankets corn and soybean fields across Read More
ManagementIllinois Leads The Nation In 4R Certified Nutrient Mana…
April 22, 2016
As Illinois agriculture works to educate farmers about minimizing environmental impact and optimizing the use of ag nutrients, Illinois now leads Read More