8 Tips For Controlling Weeds Postharvest

Have you struggled with winter annual weeds getting in the way of spring planting? Many farmers are fighting off these weeds with fall herbicide applications. Applying a herbicide now may help you save time next spring, said Aaron Hager, University of Illinois Extension weed specialist.

Before making a fall herbicide application, Hager offers a few reminders:

1. Scout fields before making any application. This helps determine what weeds are present and if their densities are high enough to warrant treatment.

2. Many herbicides used prior to or after crop planting/emergence can be applied in the fall, but not all herbicides are labeled for fall application.
Atrazine, for example, is widely used before and after corn emergence, but is not labeled for fall application. Check the label to determine if fall application is allowed.

3. Some herbicides approved for fall application have application timing restrictions on their labels. If you are considering applying a treatment (such as glyphosate) that does not possess much soil-residual activity, the application should be timed to occur after the majority of winter annual species have emerged. Instead of applying such a treatment in early-October, a mid- to late October application timing might provide better results. If your fall application will include a herbicide with soil-residual activity, then the application could be made sooner, but check the product label.

4. Combinations of one or more herbicides can broaden the weed control spectrum. This can be very important if winter annuals have already emerged before the application is made. Combining 2,4-D and/or glyphosate with soil-residual products can improve control of emerged species and help control biennial or perennial species. Include the appropriate spray additives with all applications.

5. Location in the state can influence fall herbicide applications. Fall herbicide applications seem to “fit” better in areas of central and southern Illinois. Labels may indicate fall applications that can be made only in certain geographical regions of the state.

6. Fall applications that include soil-residual herbicides may not always result in a clean field by planting time next spring.
Delays in spring fieldwork may allow the fields to green up before the crop can be planted. Occasionally, if the suite of winter annual weed species is adequately controlled, the emergence of summer annual weed species may occur sooner than if winter annuals were still present.

7. Do not utilize a fall herbicide application as an avenue to provide residual control of summer annual weed species. Control of summer annual species, such as waterhemp, is often improved when applications of soil-residual herbicides are made closer to planting compared with several weeks (or months) prior to planting. If a soil-residual herbicide will be part of a fall herbicide application, select an application rate that will provide control of winter annuals throughout the remainder of 2011, and do not increase the application rate in hopes of obtaining control of summer annual species next spring.

8. With the increasing prevalence of horseweed, including glyphosate-resistant populations, fall herbicide applications may prove more efficacious than spring applications. Glyphosate alone may not provide adequate control when applied in either fall or spring, but a fall application timing provides an opportunity to utilize higher application rates of products (such as 2,4-D) than are feasible to use in spring.

Apart from winter annual weed species, fall months may offer a good opportunity to apply herbicides for improved control of certain biennial and perennial weed species. These species often become established in reduced or no-tillage fields and can be difficult to control with herbicides once the populations are established.

For more information on controlling weeds after fall harvest, read The Bulletin online at bulletin.ipm.illinois.edu/.

(Source: Aaron Hager, Extension Specialist, Weed Science/IPM, [email protected])

Leave a Reply

Herbicides Stories

Palmer amaranth
HerbicidesSeed Industry Introduces New Palmer Amaranth Test
January 31, 2017
Weed seed can be spread in a variety of ways-including by air, animals, rain, soil and mechanical means. In a Read More
Giant Ragweed
HerbicidesHerbicide Resistance Goes Viral On Twitter
January 26, 2017
“Think differently. Behave differently. Diversify however you can. Not every practice fits on every acre.” That was the message from Read More
Giant Ragweed
HerbicidesStudy: Focusing On Weed Seedbank Can Help Manage Herbicide-Resistant Giant Ragweed
January 18, 2017
Researchers writing in the latest issue of the journal Weed Science provide important insights on the control of herbicide-resistant giant Read More
HerbicidesEPA Expands Enlist Duo Herbicide Registration To 34 States
January 13, 2017
The U.S. EPA has expanded the geography for application of Enlist Duo herbicide from 15 to 34 states. This means Read More
Trending Articles
Farmer and aptop
Matt Hopkins10 Warning Signs Your Website Is Grossly Outdated
February 8, 2017
Your Website is often a visitor’s first impression of your ag retail business. A positive first impression can set the Read More
AgriSync
Matt Hopkins17 Agriculture Apps That Will Help You Farm Smarter In 2017
December 9, 2016
Ag professionals are working smarter, not harder, than ever before. Smart farming technologies have enabled them to reduce costs, maximize Read More
R4023 Sprayer, John Deere
CropLife 100Ag Retail Equipment Report: The Green Party Continues
December 7, 2016
In the annual race for sales in the ag retail equipment marketplace, the color schemes for participants are a little Read More
Mike Stern
Precision AgClimate Corp. CEO Talks Retailer Support For Digital Ag
December 1, 2016
CropLife Magazine’s sister publication, AgriBusiness Global, recently sat down with Mike Stern, CEO of The Climate Corp., following the Monsanto subsidiary’s Read More
Precision AgTrimble Debuts End-to-End FMIS Platform
November 28, 2016
October’s inaugural PrecisionAg Vision Conference left this author with many thoughts and things to ponder in the coming months. Probably Read More
CHS Primeland
CropLife 100The 2016 CropLife 100 Report: Reviewing The Many Bulls And Bears Impacting This Year’s Marketplace
November 28, 2016
For virtually all of 2016, the nation was wholly focused on the big Presidential election. Some folks aligned themselves with Read More
Latest News
Greenleaf Technologies TADF03-D Dual Fan Nozzle
NozzlesSix Greenleaf Nozzles Approved For XtendiMax With Vapor…
February 22, 2017
Greenleaf Technologies has announced that six of its TurboDrop D Series nozzles have been approved for use with Monsanto’s XtendiMax Read More
Winter Wheat
Industry NewsTiger-Sul Hires Manitoba And Eastern Canada Account Man…
February 22, 2017
Tiger-Sul, a global leader in sulphur fertilizers and crop performance products, has announced that sales veteran Trevor Loewen has joined Read More
NFMS 17 Hagie Sprayer
Eric SfiligojThe Read From Louisville: Uncertain
February 22, 2017
By the time this column appears across the country, the annual Commodity Classic will be in full swing. This means Read More
SprayersApache 1000 Series Sprayer Earns 2017 EquipmentWatch Hi…
February 21, 2017
ET Works has been named a winner in the 2017 EquipmentWatch Highest Retained Value Awards program, the industry’s only award Read More
Measuring Bulk Tanks
StewardshipMeister Media Among 2017 Award Winners Presented By The…
February 21, 2017
The Pesticide Stewardship Alliance (TPSA) held its annual conference in San Diego, CA, earlier this month where three awards were Read More
John Reifsteck
CropLife 100GROWMARK’s Reifsteck Earns NCFC Director Of The Y…
February 21, 2017
GROWMARK Chairman of the Board and President John Reifsteck has earned the prestigious Director of the Year Award from the Read More
Roy Blunt
LegislationARA Recognizes Blunt, Heitkamp For Legislative Efforts …
February 17, 2017
Agricultural industry continues to face federal regulatory challenges. Thankfully, agriculture’s allies in the U.S. Senate stepped forward. The Agricultural Retailers Read More
LegislationThe Fertilizer Institute Commends Senate On Confirmatio…
February 17, 2017
The Fertilizer Institute (TFI) President Chris Jahn issued the following statement on the Senate confirmation of Oklahoma Attorney General Scott Read More
Trump, Senate, Cabinet
LegislationBREAKING: Trump EPA Nominee Scott Pruitt Confirmed by S…
February 17, 2017
Scott Pruitt, who as Oklahoma’s attorney general spent years suing the Environmental Protection Agency over its efforts to regulate various Read More
ManagementFebruary Road Trip Edition
February 17, 2017
Editors Paul Schrimpf and Eric Sfiligoj discuss their recent visits to Indiana and Kentucky. Read More
Heritage Cooperative Finished Building Aerial
ManagementHeritage Cooperative, Agland Co-op Approve Merger
February 17, 2017
Agland Co-op and Heritage Cooperative stockholders have both approved the merger agreement between Agland Co-op and Heritage Cooperative. Now begins Read More
LegislationARA Fly-In: Ag Retail Descends on Capitol Hill, Lawmake…
February 15, 2017
More than 100 agricultural retailers, distributors and suppliers headed to Capitol Hill Tuesday morning for the Agribusiness Congressional Fly-in, according to a Read More
Untreated soybean seed Heartland Coop
Seed/BiotechMarrone Bio Innovations, Groundwork BioAg Bio-stacked M…
February 13, 2017
Marrone Bio Innovations, Inc. and Groundwork BioAg, Ltd have announced successful seed treatment field trials of the world’s first all-biological Read More
NL5000 With G5 Technology
SpreadersNew Leader Introduces NL5000 Dry Nutrient Applicator Wi…
February 13, 2017
New Leader, a division of Highway Equipment Company (HECO), has announced the next generation of spreading technology with the NL5000 Read More
Fertilizer Storage
Crop InputsThe State Of The Fertilizer Industry
February 9, 2017
He’s all hat, no horse.” It’s a humorous way of describing a person who tells a good story, but is Read More
CropLife 100Pinnacle Agriculture Agrees To Credit Agreement Amendme…
February 9, 2017
Pinnacle Operating Corp. has entered into an amendment (the “Amendment”) to its First Lien Credit Agreement that will provide for, Read More
ManagementUpdates on Upcoming Trips, Dow-DuPont, and the Des Moin…
February 9, 2017
Editors Paul Schrimpf and Eric Sfiligoj review a few future travels, along with the latest on big company mergers and Read More
Championship Tractor Pull
EquipmentNational Farm Machinery Show Highlighted By Championshi…
February 9, 2017
The scream of monster engines, the stench of burning rubber and the ground-pounding vibrations of the country’s largest, loudest and Read More