News On The Pigweed Front

There are lessons to be learned for the Midwest from the places where Palmer amaranth resistance to glyphosate first emerged.

Most growers and consultants across the Cotton Belt got to simply watch with awe as pictures of indestructible Palmer amaranth started coming out of central Georgia, growing large, gobbling up acres and cranking out seeds in the untold billions.

Glyphosate had battled mightily for years against all unwanted plants, but in 2005 it gave up the ghost on Palmer amaranth in a catastrophic collapse that rewrote the books on weed control in the Southeast, and eventually to the Delta and beyond.

Palmer pigweed in cotton
Palmer pigweed seedhead in cotton.

“We have lost the ability to control Palmer with Roundup in these fields, and we are going to continue to lose it as resistance spreads throughout our state – especially in circumstances where we are too dependent on glyphosate.” said Stanley Culpepper, Extension weed specialist at the University of Georgia in April 2007.

Flash forward to today, and while the situation is by no means perfect, growers are regaining control of their acres from the wrath of nature.

“We had a great 2012 as far as Palmer amaranth control – in fact, we had a great crop year as well,” says Culpepper, who is still at the grindstone on the resistance management fight. “During 2013, we have not been so lucky thus far. Mother Nature has greatly challenged our growers and their ability to implement their weed management programs in a timely fashion because of the excessive rainfall preventing field operations.

“Regardless of these challenges, I am amazed how well our growers are hanging in there,” he continues. What he means is that over the past five years there has been a gradual attitude change in growers toward being proactive about the problem. Culpepper pinpoints 2009 as really the turning point in grower mentality, when they “realized what this pest was doing to them and they took it seriously. They got aggressive. They have become very good managers and they are going after it.”

Long Road Back

The evidence, as demonstrated by significantly cleaner cotton fields throughout the 2012 and even in 2013 indicates that growers are making inroads. However, it is coming at a tremendous cost. The trail of expenses starts at increased herbicide cost, which averages about $68 per acre not including the actual application, and continues with hand weeding (surveys estimate 54% of the crop in Georgia was handweeded at least once) and a variety of tillage regimens.

“Some growers are doing a lot of tillage and some none, but on average growers spent $5.84 per acre more on tillage just to manage Palmer amaranth,” says Culpepper. “It could be deep turning, cultivating, preplant incorporating herbicides, anything tillage-related.

“So obviously, the total economics of the system is not sustainable,” he adds, “and it is my job to maintain the level of control achieved during 2012, but get control programs costs down to a more economical level.”

Still, despite the challenges there were definitely some program bright spots in 2012. For example, hand-weeding costs were down about half in 2012 vs. 2010. “We were spending about $25 an acre to hand weed two years ago, but now we are in the $12-$15 an acre range,” says Culpepper. “That shows we are doing better across the board, and have become very aggressive as a whole — driven by that change in grower mentality.”

Georgia growers deep-turned over a quarter million acres of land in the last three years and cultivated about 35% of the cotton crop. “If you talked to any of our growers, nobody wants to deep turn, nobody wants to cultivate; but we had to do things to preserve the family farm,” says Culpepper. “Now as we get restarted over the next couple years to a more economical production plan, we hopefully can get back to conservation tillage and actually do it better than we ever did before.”

As far as herbicides, the last few years have provided Culpepper and Georgia growers a solid education on the pros and cons of various products, and made it possible to create the best program options possible that also preserve yield.

Monsanto’s Roundup Rewards program made a huge difference in increasing adoption of residual herbicides by providing substantial rebates on selected actives. Fully implemented it could save a grower $20 to $22 per acre in herbicides. “I don’t believe (or at least hope) anyone thinks you can spray Roundup, Roundup, Roundup any more, nor do they believe you can do the same with Liberty,” says Culpepper. “They understand that a sound management program requires that we rotate chemistry and are diversified.”

There’s also a better understanding of herbicide strengths and limitations related to timing of application. “We have learned in the last two years what happens when we spray Liberty at sunrise vs. the middle of the day, or how long products can sit in the field and remain viable without rain,” says Culpepper. “Those kinds of things can greatly influence the level of control that a grower will get, and can make or break a system.”

In the short term, Warrant preemergence is going to be an additional tool to help Georgia cotton growers because it is a great tank mix partner with Reflex, which is currently used on about 90% of Georgia cotton, says Culpepper. “Those together in combination are very effective.”

Economics will be slower to come, but for now Culpepper is willing to revel a little in the heroic efforts Georgia growers have shown so far. “We are going to be implementing a diversified crop management system across the board, it’s not just spray, spray, spray anymore. That’s not sustainable. And our growers are definitely on that,” he says.

Topics:

Leave a Reply

Weed Resistance Stories

Weed ResistanceWeeds: The Fearsome Five
October 1, 2013
Although there are currently dozens of weeds that show some kind of resistance to herbicides, these five are the most troublesome. Read More
Weed ResistanceWeed Management Program Profiles
October 1, 2013
Here’s quick look at weed control strategies and their cost. Read More
Weed ResistanceRecognizing Resistance
October 1, 2013
Recognizing the presence of herbicide-resistant weeds and formulating a total management plan is becoming more important than ever. Read More
Mature Waterhemp in Corn
Weed ResistanceWhen Weed Control Goes Wrong
October 1, 2013
Beyond the possibility of resistance developing, ineffective control exacts cost to growers in lost yield. Read More

Trending Articles

Equipment2014 Product Of The Year Voting
September 19, 2014
Many new products were introduced to the ag retail marketplace this year. From this group, CropLife IRON and its consulting partners have selected five finalists for the Product of the Year award. Please cast your vote today to help us determine the winner. 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
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

Latest News

FertilizerFertilizer Outlook And Technology Conference Set For No…
September 30, 2014
Conference participants can expect to gain perspective on the outlook for agriculture and major fertilizer materials and inputs from industry experts. Read More
MicronutrientsVerdesian Acquires Micronutrient Supplier
September 30, 2014
Verdesian Life Sciences has acquired QC Corp., a producer and supplier of granular and dry micronutrients and ferrous sulfate products. Read More
Eric SfiligojHearing From Young Ag Voices
September 30, 2014
Potential future leaders in ag retail had the chance to shine at the recent Mid America CropLife Association meeting. Read More
WebinarsUpcoming Webinars
September 30, 2014
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
Crop InputsSyngenta Appoints New Chief Operating Officer
September 29, 2014
Jon Parr will succeed retiring COO John Atkin at the end of the year. Read More
CropLife 100South Dakota Wheat Growers To Add Grain-Agronomy Facili…
September 26, 2014
Planned to be constructed in Kennebec, the facility will be located along the soon-to-be rehabilitated line of heavy-rail service from Chamberlain to Presho. Read More
CropLife 100GROWMARK Announces Vice President Appointments
September 25, 2014
Two individuals have been appointed Vice President positions on the GROWMARK executive team. Read More
FertilizerFertilizer Industry Organizations Join Global Alliance …
September 25, 2014
The Fertilizer Institute, the International Plant Nutrition Institute and the International Fertilizer Industry Association are encouraging the industry to promote the proper use of fertilizer products to minimize their environmental impact. Read More
Precision AgARA Organized Precision Forum Hits Capitol Hill
September 24, 2014
The Coalition for the Advancement of Precision Agriculture (CAPA) hosted its inaugural Precision Ag Forum, Sept. 18, in Washington, D.C. Read More
FertilizerFactors To Consider When Placing Fertilizer With Seed
September 24, 2014
The type of crop, fertilizer source, row spacing and soil environment all affect how much fertilizer can be safely applied with seed. Read More
FertilizerSidedressing Manure Into Corn Has Promising Results
September 24, 2014
Applying manure to growing crops can boost yields, reduce nutrient losses and give livestock producers another window of time to apply manure to farm fields. Read More
FertilizerWhen To Sample Manure For Analysis
September 24, 2014
Because the goal is to collect a sample that represents the manure actually being applied, the best time to sample is during loading or field application. Here's why. Read More
Syngenta
Seed/BiotechSyngenta Faces Second Lawsuit Over Agrisure Viptera Cor…
September 23, 2014
A second company has sued Syngenta AG over sales of genetically modified corn seed not approved by China. Read More
StewardshipCover Crops Field Guide For Farmers Expanded
September 23, 2014
Farmers interested in planting cover crops to improve soil health now have an updated and expanded resource in the second edition of the Midwest Cover Crops Field Guide. Read More
HerbicidesArysta LifeScience Launches Contest For Wheat Growers
September 23, 2014
The Flush after Flush Photo Finish contest encourages farmers across the U.S. to participate through Instagram or Twitter using the hashtag #FlushAfterFlush. Read More
FertilizerCF Industries Confirms Merger Of Equals Discussions Wit…
September 23, 2014
CF Industries Holdings, Inc. has confirmed that it is in preliminary discussions with Yara International regarding a potential merger of equals transaction. Read More
StewardshipProgram To Examine Ag-Related Practices, Policies To Pr…
September 22, 2014
A panel discussion on October 14 will include a significant discussion on key issues and solutions related to all aspects of harmful algal blooms. Read More
Eric SfiligojIt’s Product Of The Year Voting Season
September 22, 2014
Readers of CropLife IRON will choose 2014’s best new product over the next month. Read More