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Weed Control
Pitch a change-up to fight resistant ryegrass

Ryegrass is somewhat of a controversial plant. It was introduced to Oklahoma and Texas as a forage crop for pastures, but it also has a dark side: When it gets into crops, it can spread fast and can be very hard to control. Overuse of herbicides has led to herbicide-resistant strains, compounding the problem more and forcing researchers at Oklahoma State University to look at the problem and find new methods of control.

60-year shift in weeds tells ag’s story

Quick! Take this quiz before you look at the chart. First, were perennial weeds more common today or in the 1940s? Second, which weeds have always given Midwesterners more fits, grasses or broadleaves? Finally, how many perennial weeds were among the recent top five common weeds?

Invasive species cure worse than disease?

A long-term scientific study shows herbicides may cause more problems than they resolve for large-scale treatment of invasive species.

‘Brush sculpting’ allows quail and cattle to coexist

The tendency of many beef producers fighting brush is to clear it all off — but that may not be a wise move.

Project looks at social values of removing brush

A study in central Texas is proving the social value of brush control on rangeland.

New weed control

No big game-changing herbicide products are cleared yet this year. But Bill Curran, Penn State University Extension weed specialist, says next-generation herbicide-resistant crops are one step closer.

Biocontrols battle giant reed

In the Southwest, an exotic and invasive weed of riparian habitats and irrigation canals has become an absolute monster.

Sure-fire tips to buy right nozzles for job

Sprayers and equipment for sprayers are a major draw at the National Farm Machinery Show in Louisville, Ky. One reader says he’s going there to buy sprayer tips. He would like to buy one set of tips. He’ll spray Bicep early, then either glyphosate or glufos-inate on herbicide-tolerant hybrids.

Don’t take 2,4-D drift lightly

Anyone who has sprayed 2,4-D knows it can drift and injure soybeans. Within two to three years, Dow AgroSciences hopes to introduce 2,4-D-tolerant corn, meaning 2,4-D may become popular again.

Growers swing at pigweed using Ignite on WideStrike

It’s controversial. It breaks rules, but not laws.

Pigweed: Be afraid, very afraid

Like prophets crying in the wilderness, Larry Steckel and fellow weed scientists in the Mid-South have been sounding off about the coming woes of glyphosate-resistant Palmer amaranth, or pigweed.

Seed treatments abound

We talked last month about choosing hybrids and varieties to plant — a daunting task by itself. To add to the challenge, you also get to pick from among many different seed treatments.

Impede weeds

Growers across the Southeast wondered what would replace Deltapine’s 555 in their cotton fields.

Play a new herbicide card in corn weed control game

Recent University of Georgia crop enterprise estimates suggest field corn has the potential to be one of the most profitable crops grown in this region in 2010. When I wrote this article in January, March to December corn contracts were selling between $4.21 to $4.48 per bushel. I hope it stays that way. Having corn in a rotation where atrazine and other modes of action can be used is a great way to combat glyphosate and ALS resistance!

Killer weeds

When one door closes, another one opens.

Curbing noxious weeds

Weeds are thieves, not only in the night, but also in the day.

Ranchers in Wyoming declare war on cheatgrass

Cheatgrass is a scourge for many ranchers in Wyoming and the West. It has the capability of turning desirable livestock and wildlife range into a hazy purple wasteland.

Weed districts, chemicals aid battle

Is it financially worth controlling cheatgrass? That’s a question facing many ranchers in Wyoming and the West.

Watch these weeds

Wintry months of historically high and frequent rain, sleet and snow have provided some of the best prospects in years for crops in Texas and the Southwest this spring. But it also gave some mighty good prospects for weeds to run rampant.

Spot resistance

Do you know how to identify glyphosate-resistant weeds in your fields this summer?

50-year saga in battle against weeds

Tom Bauman’s roots in weed control date back to when cultivation was king. Farmers applied granular herbicides like Ramrod over the row. Today, they plant crops with built-in tolerance to broad-spectrum herbicides.

Toasted soybeans deserve closer look

The Crops Corner panel of Indiana Certified Crop Advisers (see Page 22) tackled this tough question:

Take best shot at controlling runaway, resistant ragweeds

Lucky people hide the field they don’t want anyone to see in the back 40. Those less fortunate discover it’s the field right out front. If you’ve got a field of soybeans with glyphosate-resistant giant ragweed patches, maybe you don’t even want to see it.

Consider top tips for fall herbicide applications from several weed experts

Willis Smith’s No. 1 tip is to use a herbicide or combination of herbicides that targets the weeds you’re after. The Certified Crops Adviser with Senesacs also suggests using a mix with burndown capability. You still want residual activity to carry you as far into spring as possible. Beware, however, that you may then be committed to a specific crop.

Time to take out Canada thistle

Here’s a question you might find on an agricultural version of “Are you smarter than a fifth grader?” If you could only spray Canada thistle during one season of the year, which would it be?

Rain, residual shortages add to weed woes

For cotton growers, frustration ruled in Arkansas and rains accelerated their problems in Tennessee.

Weed control update for 2010

A number of new herbicides and herbicide combinations have become available recently. Here’s a summary of some of the new ones, as well as a few introduced last year. Iowa State University Extension weed scientist Mike Owen provides this update.

Battling a prehistoric weed

Scouringrush has probably been around for some 300 million years. With no leaves and very little branching, it has several names like snake grass, jointed grass, horsetail or horsepipes. Unique and interesting, this hollow green-stemmed prehistoric plant in the horsetail family can become a problem weed when it creeps out of streams, waterways and marshy areas into corn and soybean fields.

Fall is best time to mount attack on weeds

If the good weather continues to hold through harvest, this fall will be the best time to get aggressive about weed control, especially if you’re dealing with dandelions, glyphosate-resistant weeds or plan to rotate out of an old alfalfa stand.

Herbicide-resistant sorghum nears

The United Sorghum Checkoff Program has been funding research to showcase new over-the-top solutions for controlling grass to allow sorghum growers better management opportunities and flexibility in crop rotations.

Kill weeds before you kill the turkey

Although Texas and Oklahoma are neighboring states, they don’t always have the same weed problems, especially for winter wheat. Oklahoma fields recently have been invaded by grassy weeds, including cheatgrass and annual ryegrass. For many growers, that ryegrass has been exhibiting increased resistance to herbicides. More than 15,000 acres of wheat have ryegrass that displays some level of resistance, and it seems to be getting worse.

Rotate crop herbicides, advises weed specialist

Texas crop farmers are advised to give serious consideration to rotating herbicides as the potential for resistance to certain compounds becomes more common, according to a Texas AgriLife Extension Service specialist.

Resistant weeds a growing issue

It’s been a difficult year for weed control. The issue isn’t that weeds in general have not been controlled by the herbicides, particularly those applied postemergence. Rather, the issue was finding the opportunities to make the applications in a timely manner.

Goats, proper irrigation control weeds

Don Morishita, University of Idaho professor of weed science, reminds growers that moisture makes the weed.Some weed, like knapweed, are a problem in dry areas, while others such as foxtail are found in wet areas. Weed control can depend more on how much you irrigate.

Look at LL beans as alternative

It wasn’t too many years ago when we were thinking that Roundup was bulletproof. We figured we’d be applying it year after year across most of our acres. We now know that Roundup isn’t bulletproof, and growers all over the U.S. are figuring out how to manage their rotations and cropping plans differently.

Probing resistant genes

In hand, even the experts can’t tell the difference between weed seeds that are resistant or susceptible to glyphosate.

Fighting pigweed? Respect the Rotation

Those already living the nightmare walk the fields with hoes in hand and a changed mindset. And those still staring into the abyss of weed resistance are flat-out scared.

Weed resistance close to ‘onslaught’

It’s almost scary how serious the problem is, says Bob Nichols of Cotton Incorporated.

BMPs are vital with re-registration of herbicide atrazine

As part of the re-registration of the popular herbicide atrazine, farmers should adopt best management practices, or BMPs, to prevent runoff and ensure that atrazine remains a viable product, says a University of Missouri Extension water quality specialist.

Green stem syndrome prevalent in 2010

Despite record soybean production in 2010, yields could have been even better, says a University of Missouri Extension specialist. One reason was green stem syndrome, or GSS.

What’s new in cereal-crop, forage-grass weed control

In February’s issue, Penn State University Extension weed specialists Bill Curran and Dwight Lingenfelter teamed up with Cornell University’s Russ Hahn for an update on corn and soybean weed control. They noted that common chickweed seemed to be developing resistance to Harmony SG, Harmony Extra and products containing thifensulfuron’s mode of control in small grains.

Seven tips to stop spread of weed resistance

Maybe your Achilles heel is marestail. Or perhaps it’s giant ragweed. Whatever weed you fear may become resistant, Danny Greene offers tips to thwart future spread of resistance. Greene, a certified crops adviser, operates Greene Consulting Inc., Franklin.

Timing of weed control is key to victory in protecting yield

When it comes to postemergent weed control in corn, timing is everything. While the vast use of glyphosate herbicides and herbicide-tolerant seed has curbed weed pressure, the development of resistant weeds has made the timing of weed control more important than ever. If farmers wait too long in the growing season to treat, they can expect yield reductions.

Start right with residual

With current advantageous grain prices and our ability to produce impressive yields, we have the potential to generate some great gross margins this year if the weather cooperates and we implement sound crop and pest management. Let’s focus on one key management strategy in this article: using a residual herbicide to complement your post-program in corn and soybean fields.

Texas gets weed control in dry fertilizer

Texas cattle raisers have another way to get weed control in pastures — in one step.

Clearfield technique tops with growers

New Clearfield wheat varieties are clearing the way for more rapid adoption of the Beyond herbicide technology, but growers are warned to pay close attention to new supplemental labels for the herbicide to assure they are using it correctly and legally.

Waterhemp is escaping — again!

Waterhemp has done it again. University of Illinois researchers have confirmed that waterhemp is the first weed to evolve resistance to HPPD-inhibiting herbicides — after escaping glyphosate, ALS inhibitors and PPO inhibitors.

Get the jump on resistant weeds

"Learn from our mistakes,” says Ford Baldwin, of Practical Weed Consultants, Austin, Ark. “You can avoid all this.”

Scientists look at how nature makes a weed

In a lab, some 1,300 miles away from the nearest Mid-South rice field, a researcher works to learn what makes a weed a weed.

What is herbicide stewardship?

A consistent theme these days is the need to provide stewardship for weed control when planting corn and soybean varieties that are resistant to glyphosate and glufosinate herbicides. The goal of promoting stewardship is to preserve the value these traits and herbicides bring to agriculture.

Italian ryegrass resistance vexes scientists

Herbicide resistance of Italian ryegrass is glowing brightly on the Pacific Northwest research radar.

Arkansas proves no state safe from glyphosate resistance

In more ways than one, Arkansas has become the Wild West of weed pressure. The weeds are out of control. Farmers are desperate. Some folks are facing full-blown glyphosate-resistant populations of giant ragweed, common ragweed, johnsongrass, marestail and waterhemp.

Enlist packs a double punch

By now, most have probably heard of Enlist, Dow AgroSciences’ new weed control cropping system that will launch in corn in 2013 and in soybeans in 2015. For those who haven’t, in a nutshell, it combines glyphosate tolerance with 2,4-D tolerance.

It’s a spray trailer, not a jungle gym!

When Scott Williams goes to the field, he wants to spend as much time spraying as possible. That means making fast but accurate fill-ups. Williams and Jason Misiniec built a semi-bed spray trailer that acts as a mobile fill-up station for a self-propelled sprayer.

Trees sprout up as pests in no-till fields

No-till farming has numerous benefits, but one issue that comes with the practice is trees sprouting up in fields next to corn and soybeans.

Know Nebraska’s ‘noxious 11’

Warm weather and summer storms aren’t just favorable for growing corn. Weeds flourish as well in this state. Although Nebraska has 11 designated noxious weeds, landowners have a variety of resources that they can use to distinguish friend from foe.

Resistant pigweed is a call for change

"Change” is a word tossed about a lot nowadays in political circles. Glyphosate-resistant Palmer amaranth (aka careless weed or pigweed) found in far West Texas this growing season will require growers to change their weed management from just glyphosate herbicide alone.

More weed resistance this year

Weed resistance to herbicides continues to become a more widespread problem in Iowa and elsewhere, as evidenced by the number of weedy fields late in the 2011 growing season.

Herbicide carryover a concern?

Yea, I know, I’m one of the guys who have been pounding the rock, promoting the use of residual herbicides to increase productivity and profitability, and help manage herbicide resistance. Now I bring you this topic: potential carryover of some of these same residual herbicides. Go ahead and say it; I can take it. As the guys on Monday Night Countdown say, “C’mon, man!”

Consider plants, property goals in brush control

There are so many combinations of ways to control brush it is mind boggling. But hold on — think it out before you start.

Jump on next spring’s weeds this fall

With rough weather blanketing the nation at the beginning of the growing season last spring, weed control has been much more of a challenge this year. Yet, growers fighting escaped weeds still have the opportunity to start fresh next year by implementing a fall burndown program.

New research puts weeds under fire

Weeds are a real pain. For organic farmers, weeds are the biggest obstacle in a quest for high yields and profitability. Because organic growers can’t use herbicides, cultivation and hand weeding are their most widely used options.

FMC unveils landmark herbicide

Those who thought there would only be a handful of chemical companies left by now miscalculated. FMC Corp. began a transition from a company just selling insecticides to a company selling herbicides with Authority, and then Cadet, five years ago.

Weigh pros, cons of spraying weedy fields

Due to a combination of conditions, some soybean fields aren’t as clean as usual, even with Roundup Ready varieties sprayed with glyphosate. Is this a year when it might pay to spray fields with green weeds early so harvest goes smoother?

Hitchhiking weed seeds spread for miles

When you take a four-wheel drive out for a spin, you could be bringing home more than memories.

The latest in weed control for 2012

What’s new in weed management for 2012? While there haven’t been any new herbicide products introduced for 2012 (as of this writing), there are several products pending registration. There are some “new” generic herbicides and changes in herbicide labels. Following is a partial list of these changes. The list is provided by Mike Owen, Iowa State University Extension weed scientist.

Resistant pigweeds zap cotton in Southern states

Without a doubt, weed resistance to herbicide was the hot topic at the 2012 Beltwide Cotton Conferences in Orlando, Fla.

Fighting pigweed yearlong

When glyphosate resistance reared its ugly head in the Delta, Keith Baioni listened to farmers and came up with a way to help.

Fast-start spring

June-like weather in March gave weeds a huge head start this spring. Soil temperatures in March matched what Iowa normally has in late April and early May. A mild winter and warm spring create greater weed challenges, especially for no-tillers. Winter annuals can turn fields green by late March. And weeds such as marestail grow faster and reach stages difficult to control much sooner than in a “normal” spring.

Control weeds early

No farmer would argue that allowing weeds to grow with a soybean crop reduces yield and profit potential. But some may argue at exactly what point weeds begin to steal yield. “Anytime a weed emerges and begins growing, it competes with the crop for nutrients, water, sunlight and space,” says Jim Frederick, Syngenta agronomy representative in southern Iowa. “If left unchecked, emerged weeds can cause problems and reduce yields.”

Two ways to handle weed resistance

Does anybody really care about glyphosate-resistant weeds? It seems there are a few farmers who are avoiding glyphosate-resistant weeds by rotating LibertyLink or conventional varieties in their corn-soybean rotations, and there are the majority who are planning to use mainly glyphosate until it quits working, and then add pres and tankmix partners for the extra $10 to $20 per acre.

Wet conditions intensify need for Foxtail barley control in no-till wheat

Wet conditions over the past couple of years have resulted in greater populations of foxtail barley, a very difficult weed to control in no-till wheat. Although foxtail barley flourishes in wet, alkaline soils, it can also spread over an entire field. It is difficult to control because it is a clump-type perennial that grows rapidly in the spring and matures relatively early, often around the end of May or early June. After its first year of growth, it can be nearly

Fighting kochia poses challenge due to glyphosate resistance

Glyphosate-resistant kochia is becoming more common in northern South Dakota between the Missouri River and Highway 281. This could become a challenging weed in Roundup Ready soybeans as there are few effective postemergence herbicides available.

Take waterhemp battle to beets

Glyphosate-resistant waterhemp can be managed in Roundup Ready sugarbeets.

Year-round weed control for Fuchs

Bob Fuchs doesn’t wait until spring to begin combating weeds.

Weed resistance a global threat

The evolution of herbicide-resistant weeds is not a new issue. But the problem has come to the forefront with widespread use of glyphosate and more difficulties with weeds resistant to the herbicide. A national summit in May identified strategies to address herbicide-resistant weeds where they have emerged and identify steps to act proactively (use best management practices) to preempt further evolution.

LibertyLink system must be protected

Cotton growers have the opportunity to use LibertyLink varieties again this year, giving them a new option against weeds, most notably glyphosate-resistant Palmer amaranth. But North Carolina State University weed specialist Alan York says growers must work together to avoid allowing weeds the opportunity to develop resistance to glufosinate, the new herbicide product that LibertyLink varieties can tolerate.

Watch for new herbicide names this year

If this story was just about new herbicide active ingredients, it would be very short, notes Bill Johnson, Purdue University Extension weed control specialist. The pipeline on brand-new products is running very lean, he says. However, there are new names and new combinations of existing ingredients.

Go after resistant waterhemp

Waterhemp is a weed that’s starting to make noise in Indiana. Bill Johnson, a Purdue University weed control specialist, recently issued a press release about waterhemp.

Take down more weeds

Farm shows aren’t just about huge machinery. Companies also debut new herbicides and other products that could help you do a better job next spring. Here are options for new herbicides, or ways to make existing programs work better.

Weed resistance marches on

Herbicide-resistant weeds continue to gain ground in Nebraska in 2011, prompting University of Nebraska specialists to call for more integrated weed management programs that include rotating products with different modes of action.

Pigweed resistance spreading in Texas

When Palmer amaranth or pigweed resistance to glyphosate herbicide was confirmed on the Texas High Plains in Terry County near the New Mexico border last summer and fall, it was a wake-up call.

Glyphosate: What’s fact, fiction?

Labeled an “explosive topic,” glyphosate disease susceptibility and weed resistance was high on the agenda for the Pacific Northwest Direct Seed Association’s annual meeting in Spokane, Wash., earlier this year.

‘Huge’ increase in resistant weeds

North Dakota State University agronomists are receiving many phone calls and email messages about suspected herbicide-resistant weeds this summer.

New invasive weeds

Common tansy was recently identified along a roadside in northeast South Dakota. This weed has been well established in western Minnesota for several years, so it is not too surprising to see it in eastern South Dakota, says Mike Moechnig, South Dakota State University Extension weed specialist.

Herbicide guide available on ISU website

The 2013 Herbicide Guide for Iowa Corn and Soybean Production can be accessed at The publication provides an update of new herbicide products, as well as a effectiveness chart for herbicides used in soybean and corn production.

Glyphosate-resistant kochia ‘explodes’ in Kansas fields

Back in 2007, Kansas State University specialists confirmed the presence of glyphosate-resistant kochia in Kansas. In 2010, they added several confirmed sites of problems.

Palmer amaranth in Michigan

Palmer amaranth was first discovered in Michigan in fall 2010 when a grower reported he was having difficulties controlling a “pigweed” in his soybean field with glyphosate, the active ingredient in Roundup Ready herbicide.

Negative impacts of insurance sprays

The looming potential for spider mites in parts of Michigan raises an important issue: the impact of preventive or insurance pesticide applications on insect or mite control.

Leaving too much yield in the field

It did not take long after leaving a field day at the University of Missouri Bradford Research and Extension Center to find an on-farm example of Kevin Bradley’s latest talk.

Volunteer corn bad for crop ecosystem

Volunteer corn growing in soybean fields that originated from Bt corn the year before may be much more onerous than it looks. One possible negative effect is obvious: soybean yield loss. The other downside is more subtle, but could be just as damaging. It relates to promoting insect resistance.

Scrutinize no-till plant stands

This fifth article in the Tough No-till Q&A series tackles evaluating no-till crop stands. Russell McLucas, Pennsylvania No-Till Alliance board member, and Del Voight, Penn State University Extension grain crop specialist, address concerns and the secrets to high-yielding stands.

New herbicides added to your weed control kit

Weed control systems expanded for 2010 if you’re using Roundup Ready or LibertyLink hybrids. Several new options are designed to help improve overall weed control in these systems.

Stories behind crops quiz photos

Your December Indiana Prairie Farmer featured 10 pictures in the annual Indiana Prairie Farmer/Beck’s Hybrids Crops Knowledge contest. If you don’t have your issue handy, visit on the Web, click “More Indiana Prairie Farmer,” then “Magazines Online.” You’ll find the story on Page 7 in the December issue.

Indiana farmer wins idea prize

If you’ve ever cleaned spray nozzles and found one or more was still plugged when you got back in the cab, you’ll be interested in an innovation that DeWayne Jones came up with. Jones was one of 15 farmers and ranchers from around the country who brought their equipment modifications, marketing techniques and other innovations to the American Farm Bureau Federation annual meeting in Seattle.

Link up with new soybean system

At the time I penned this article in November, July 2010 soybeans were trading for $9.72 per bushel. Thus, interest in soybean production remains strong. One of the newest weed management tools to hit the market is the LibertyLink soybean system. Many growers are counting on this system to help them control glyphosate- and ALS-resistant weeds. This system can work, but it’s not foolproof. Here are some useful tips based on my experiences.

Lifting cotton profits

Meticulous management, both in the field and the office, make the difference in profit or loss for dryland cotton on the Rolling Plains of Texas.

Plug holes in your soybean regime

Wait to increase soybean yields? Then imagine putting the crop’s maximum yield potential — around 100 bushels per acre today — in a bucket, a bucket with six or seven holes in it, advises Karen Corrigan, of McGillicuddy Corrigan Agronomics.

Getting fired up

John Majerus of Cedar Rapids worked on his first prescribed burn this spring as a new member of the 3-year-old Central Nebraska Prescribed Burn Association. He and eight other members conducted the burn on a 30-acre native pasture owned by Pete Berthelsen of St. Paul.

Take time to save time

If I had a dollar for every time I shared or heard that old adage “Time is money,” I wouldn’t have been stuck in Iowa all winter. Time is always at a premium during planting season, and I have a feeling this season it’ll be even more valuable.