Hot, Dry Weather Make It Harder To Control Weeds

While the extended periods of hot, dry weather Ohio has experienced in recent weeks may mean that weeds aren’t growing as fast as they would in more moist conditions, the weather can still have an adverse effect on weed management for growers, an Ohio State University Extension expert said.

Not only does the extended hot, dry weather and drought-like conditions impact the germination, growth, hardiness and competitive ability of weeds, but the dry weather conditions also complicate weed control efforts, said Mark Loux, an OSU Extension weed specialist.

“The biggest thing that happens to weeds when the weather conditions continue to be hot and dry is that the weeds get tougher to control,” he said. “Under good moisture, weeds tend to be more sensitive to herbicides.

“Under extended dry conditions, weeds grow more slowly and also develop thicker cuticles on the leaf surfaces, which has the overall effect of reducing herbicide movement into and throughout the plant.”

While growers often times wonder if they should wait for rain to treat weeds with herbicides or apply treatments now, Loux said, the most important thing to consider is to make sure they select the right herbicide treatment for the weeds they are trying to control.

“Growers should go ahead and spray when the weeds are small,” he said. “With the continued forecasts for little to no rain, you’re better off at this point to just pull the trigger.

“And if you spray now and it does rain and bring on the next growth of weeds, go ahead and spray again.”

Loux said that growers who wait too long could end up losing control of the weeds they currently have and may also have to spray again for the next batch of weeds that emerge in their fields.

“And if you wait to spray and then are forced to use a more aggressive herbicide mix, it can increase the level of crop injury,” he said.

Following are some tips for growers to consider:

  • Apply herbicide when weeds are small. Large and old plants become even more difficult to control when subject to extended dry conditions. Prolonged dry conditions also suppress additional weed-seed germination, so the risk of many weeds emerging after an early post-treatment is reduced.
  • Optimize adjuvants. Labels for some POST herbicides provide suggestions for revised adjuvant rates or types under dry conditions.
  • Dry weather does not usually increase the severity of injury to the crop from herbicides, unless coupled with very hot conditions. But continued dry conditions after the crop has been injured can reduce its ability to recover from injury, or extend the time needed for recovery.
  • Applying herbicides when weeds are small minimizes the need for more aggressive herbicide mixtures.
  • If you are finding that you can’t control glyphosate-resistant marestail with glyphosate plus either Classic or FirstRate, then adding other herbicides won’t help.
  • Instead, walking the fields to remove plants by hand, or at least cutting the tops off later in the season to prevent seed production, is likely the best option.

Continuation of dry weather throughout the summer will reduce the rate of dissipation in soil of certain herbicides, possibly increasing the risk of carryover into next year’s crop.

Topics:

Leave a Reply

Herbicides Stories

Crop InputsEU Glyphosate Controversy Heating Up Yet Again
August 17, 2016
The battle over glyphosate rages on in Europe, creating a lot of question marks over whether the herbicide will continue Read More
Winter Wheat
HerbicidesNew Wheat Herbicide Helps Growers Manage Resistant Weeds
August 2, 2016
Quelex herbicide from Dow AgroSciences is now registered by the U.S. EPA, providing wheat growers a new solution for advanced Read More
Palmer pigweed seedhead in cotton
HerbicidesStudy: Fall Weed Controls Can Make Significant Impact On Glyphosate-Resistant Palmer Amaranth
July 28, 2016
An article published in the latest issue of the journal Weed Science shows that adopting harvest-time and post-harvest weed controls Read More
Palmer pigweed in soybean stubble
HerbicidesSpecial Issue Of Weed Science Explores Human Aspects Of Herbicide Resistance
July 27, 2016
Weeds that evolve resistance to herbicides are a serious threat to global agricultural production. In this Special Issue of Weed Science, Read More
Trending Articles
Key Cooperative Marcus Construction Steel Building
Retail FacilitiesMarcus Construction Builds High-Speed Agronomy Center For Key Cooperative
July 7, 2016
Key Cooperative in Grinnell, IA, wanted a state-of-the-art Agronomy Center to better serve its customers. Marcus Construction delivered exactly that. Read More
Heritage Cooperative
Retail FacilitiesKahler Automation Designs State-Of-The-Art Facility For Heritage Cooperative
July 4, 2016
Heritage Cooperative in Marysville, OH, needed an efficient liquid, dry and grain facility to serve the many needs of their Read More
The Andersons Waterloo
ManagementFirst Indiana Facility Certified Under 4R Nutrient Stewardship Certification Program
June 27, 2016
The 4R Nutrient Stewardship Certification Program has announced that The Andersons, Inc.’s Waterloo, IN, facility has been added to its Read More
Food IT
Industry NewsCalifornia Event Will Mix Ag And Tech Professionals To Explore IT Solutions
June 20, 2016
Silicon Valley is hot on agriculture, and an upcoming event in California will bring together the food and tech industries Read More
Monsanto Luling Plant
Eric SfiligojWhat’s Next For Monsanto?
May 31, 2016
For the folks at Monsanto’s headquarters in St. Louis, MO, it has been an eventful few weeks. Back on May Read More
Soybean Plant closeup
Industry NewsMonsanto Rejects Bayer Bid; Open To More Talks
May 25, 2016
Monsanto Co, the world’s largest seed company, turned down Bayer AG’s $62 billion acquisition bid as “incomplete and financially inadequate” Read More
Latest News
Monsanto sign
Crop InputsCould a Monsanto-Bayer Union Be 2 Weeks from Fruition?
August 24, 2016
Via STLToday.com (The St. Louis Post-Dispatch): Merger talks between Monsanto Co. and Bayer AG are advancing after a series of Read More
EquipmentCase IH Debuts Nutri-Tiller 955 Strip-Till Applicator
August 24, 2016
With strip-till continuing to expand across new acres, Case IH designed the new Nutri-Tiller 955 strip-till applicator to help producers Read More
EquipmentCase Launches Aim Command FLEX, 25th Anniversary Patrio…
August 24, 2016
Case IH announces new AIM Command FLEX advanced spray technology for greater application accuracy, as well as special 25th Anniversary Read More
ASMARK 2016 Retailers Live! Tour - CPS
CropLife 100CPS Acquires Texas Retail Operation
August 23, 2016
Crop Production Services (CPS) has acquired the assets of Larry’s Chemical and Spray, Inc., for an undisclosed amount in an Read More
PrecisionAg Video Conference
Precision AgVideo: PrecisionAg Vision Conference
August 22, 2016
A Strategic Conference Focused on the Future of Farm Digitization and Precision Agriculture Visit precisionagvision.com and register today! Read More
Young Corn Plants
Industry NewsOABA Welcomes Nicole Wallace As Communication & Adm…
August 22, 2016
The Ohio AgriBusiness Association has hired Nicole Wallace as its communication and administrative coordinator. Wallace will help provide comprehensive communication Read More
Syngenta Sign
Crop InputsChemChina, Syngenta Receive Clearance From CFIUS
August 22, 2016
China National Chemical Corp. (ChemChina) and Syngenta have announced that the companies have received clearance on their proposed transaction from the Read More
ManagementAg Industry Shows and Rumors
August 18, 2016
Editors Paul Schrimpf and Eric Sfiligoj talk about the upcoming trade show schedule, crop protection merger updates, and content for Read More
MAGIE 2015
EquipmentMAGIE Takes The Pulse Of The Ag Retail Industry
August 18, 2016
Every year, one of the major highlights of my career as an ag journalist is attending the Midwest AG Industries Read More
MAGIE 2015 Overview
EquipmentPride In Professionalism On Display At MAGIE
August 18, 2016
The Illinois Fertilizer & Chemical Association (IFCA) is proud to partner with CropLife IRON and continue the tradition of bringing Read More
SprayersJenner Ag To Debut 25th Anniversary Edition Case IH Pat…
August 18, 2016
Visitors at the 2016 Midwest Ag Industries Exhibition (MAGIE) in Bloomington, IL, will have a unique photo opportunity, as Jenner Read More
Crop InputsEU Glyphosate Controversy Heating Up Yet Again
August 17, 2016
The battle over glyphosate rages on in Europe, creating a lot of question marks over whether the herbicide will continue Read More
Industry NewsNew Partnership Provides Improved Representation At Ohi…
August 16, 2016
The Ohio AgriBusiness Association (OABA) has retained Belinda Jones of Capitol Consulting Group, Inc. (CCG) for government relations work in Read More
Tissue testing
FertilizerMosaic: 6 Tips For Better Crop Nutrition In Corn
August 16, 2016
Late in the crop season is a good time to assess visual nutrient deficiencies and ensure early- and mid-season deficiencies Read More
WebinarsWebinar Schedule
August 14, 2016
Register for one of our upcoming Webinars or access our archive of past Webinars to view recordings of presentations that may be of interest to you. Read More
Dow DuPont
Crop InputsDowDuPont Update: EU Takes Closer Look at Merger
August 12, 2016
Dow Chemical Co. and DuPont Co. face months of haggling with European Union antitrust regulators who opened an in-depth probe Read More
ManagementNews from InfoAg 2016 and Weed Wands
August 11, 2016
Editors Paul Schrimpf and Eric Sfiligoj review what happened at last week’s big Precision Ag event and a possible solution Read More
Crop InputsFBN: We’re ‘Here To Stay’
August 11, 2016
PERSPECTIVE — If you’ve been following this site for a while you might remember a certain editorial we published on Read More