Worst pest since the weevil striking at cotton farmers
- Details
EXTRACTS: [Calhoun County cotton, soybean and corn farmer John Olson] said a good way to describe the 2008 agriculture year would be "year of the weeds."
[Charles Davis, Calhoun County Clemson Extension agent and crop specialist for Orangeburg and Calhoun counties] said while neighbors to the south in Georgia have seen some cotton fields totally wiped out from the pigweed, no local fields have experienced total devastation.
"We have not abandoned any farms yet like they have in Georgia," Davis said. "And we don't want to get there."
"But in the near future, if we are not careful, we will see fields that are heavily infested."
...both Davis and Marshall [Blackville Edisto Research and Education Center weed specialist Dr. Mike Marshall] say the overuse and reliance on glyphostate have helped to make the pigweed resistant.
For some experts, the weed is considered the worst since the boll weevil, a beetle that... devastated thousands of cotton fields three decades ago.
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Worst pest since the weevil striking at cotton farmers
By GENE ZALESKI, T&D Staff , The Times and Democrat, August 11 2008
http://www.thetandd.com/articles/2008/08/11/news/doc48a0b9335b8c2586375444.txt
Palmer amaranth is its scientific name but local cotton experts call it a pigweed.
The weed can grow 6 to 10 feet tall -- an inch a day even during droughts -- and is known to be resistant to the most common herbicides used in cotton, namely glyphostate.
By whatever name, one word used to describe the weed is "nasty" and its nastiness is of concern to T&D Region cotton experts.
"It is bad and it is widespread," said Charles Davis, Calhoun County Clemson Extension agent and crop specialist for Orangeburg and Calhoun counties. "Three is gracious plenty of resistant palmer in Calhoun and Orangeburg counties."
Davis said the weed and its resistance have been common discussion at local cotton production meetings. And now that the weed has reared its ugly head more prominently, it will most likely continue to be at the forefront of growers' minds.
"My Lord, yes," Calhoun County cotton, soybean and corn farmer John Olson said, when asked if palmer has been a problem. "We are having a terrible problem with it. We are going to change chemicals next year or we will be overwhelmed by it."
Olson said he has already resorted to WideStrike herbicide as one option to cut back on the weed.
If this does not help, "I don't know what we are going to do," Olson said.
Olson said a good way to describe the 2008 agriculture year would be "year of the weeds."
"We got to get a whole new chemical, a complete overhaul on our chemical program," he said.
Davis said outreach methods to farmers will continue to encourage them to be vigilant and the need look into using multiple herbicide packages in preventing the weed from coming up in the first place.
Davis said while neighbors to the south in Georgia have seen some cotton fields totally wiped out from the pigweed, no local fields have experienced total devastation.
"We have not abandoned any farms yet like they have in Georgia," Davis said. "And we don't want to get there."
Palmer amaranth crowds out cotton plants, starving them of sunlight, nutrients and water, and is a very productive weed. Each female produces as many as 500,000 seedlings, meaning just one plant can birth an entire field.
Unlike other pests, pigweed can continue to grow an inch a day even without water, making it particularly adept during the drought gripping the region. It also thrives in hot weather, continuing to grow when temperatures top 90 degrees and other plants shut down.
The weed can even damage cotton pickers, the huge machines that pluck natural fiber from the cotton bolls.
For some experts, the weed is considered the worst since the boll weevil, a beetle that lays eggs in the plant's boll and ruins it. The insect devastated thousands of cotton fields three decades ago.
"It is an aggressive weed that can produce millions of seeds per plant," Blackville Edisto Research and Education Center weed specialist Dr. Mike Marshall said. "For a weed, it has all the benefits -- it is fast-growing, a high reproductive rate, and is very aggressive. It has found a perfect niche in our fields."
Many pig weed plants were held at bay by cheap herbicides.
But only the most aggressive and expensive chemical treatments have worked against the resistant variety, and even those hardly manage to contain them.
Glyphostate is sold under several brand names, but the leading product is Roundup, made by Monsanto.
The company revolutionized cotton growing in the 1990s when it introduced BT cotton -- cotton that was genetically engineered with its own built-in pest defenses. Monsanto also introduced Roundup Ready cotton -- plants that wouldn't perish with the weeds when a field was sprayed with a glyphostate herbicide.
Those two developments enabled cotton growers to drastically reduce the amount of chemicals used in their fields and switch to conservation tillage, which reduces soil erosion and helps to retain moisture in the soil. The improved efficiency also lowered costs for such things as labor, equipment and fuel.
But both Davis and Marshall say the overuse and reliance on glyphostate have helped to make the pigweed resistant.
Marshall said there are some products and pre-emergent herbicides that can be used and mixed with Roundup such as Reflex, and FlexStar or Valor.
“Basically, the herbicide is the key and the lock is the part it acts on,” Marshall said. “When a weed becomes resistant, the lock changes and the key does not work any more. Weeds are highly adaptive plants.”
In light of this, Davis said local farmers are actively searching and applying alternate chemical systems to help keep the weed at bay.
"But in the near future, if we are not careful, we will see fields that are heavily infested," Davis said.
Before Roundup Ready cotton, farmers often had to plow the field to bury weeds and their seeds and then protect the crops from pests with heavy chemical applications. Now many use conservation tillage, which barely disturbs the soil.
Davis said a few farmers in the area that are going to what is called no-till cultivation using a specialized equipment to cut the roots of the weeds without disturbing the soil. But he says this has not proven the most practical way of reducing the weed, due to its slowness.
"We will depend on herbicide activity to keep the weeds down," he said.
Marshall said while he would not advocate going back to tilling the soil, it should at least be an option considered and not rejected outright.
"I know people don't want to hear that, but it is an option to use with soil-applied herbicides," he said.
T&D Staff Writer Gene Zaleski can be reached by e-mail at This email address is being protected from spambots. You need JavaScript enabled to view it. or by phone at 803-533-5551. Discuss this and other stories online at TheTandD.com