For better nematode control – Know Your Soil Types

Every year, cotton growers face two invisible pests that strike without warning, leaving rows of stunted, withered plants. The root knot and reniform nematodes are among a cotton grower’s most devastating enemies. Because they do most of their damage at the roots, they can destroy entire rows of young cotton plants before growers realize they have a problem. In fact, both species of nematodes together cause average losses of over 2% of the total U.S. cotton crop every year, valued over $100 million.

Something Old, Something New
In early July, Weldon Shook gazed across his cotton field ravaged by adverse weather and nematodes. But like most farmers, he was looking on the bright side. “For all it’s been through with weather and nematodes, I’m actually proud of this cotton field. If this field makes 2 bales average, I’ll be pleased,” said Shook, a Seagraves, TX, producer who’s always on the lookout for new crop management ideas. Much of the optimism he expressed that day in early July was based on how much better the cotton was progressing where he had tested a new combination of old and new – his usual Temik in-furrow application, along with N-Hibit Seed Treatment.
“It seemed to give the treated cotton an added ability to withstand stresses like the cool, wet, and windy weather we experienced right after planting and emergence of the cotton,” he explained.
Replicated trials in Southern and Midwestern states have shown that the Harpin protein in N-Hibit reduces the number of nematode eggs among plant roots by an average 50% or more. Harpin does not act directly on the disease organism, according to EPA information, nor does it alter the DNA of treated plants, but instead activates a natural defense mechanism in the host plant.
The Texas A&M Cooperative Extension Service has been soil testing on farms in two counties to the north of Seminole for 10 years, and finds that 80% of the surrounding acreage has some level of nematode infestation, with 60% of those acres requiring a nematicide. “We need more tools to help us manage nematodes, so I will try new technologies as they come along,” Shook said. “I heard about N-Hibit at the Sandyland Ag Conference in Seminole in 2006, and decided this year I would test it.”
The test field made just under 4 bales per acre in 2006, but this year it looked as though it might have been on another planet. At planting on May 7, the weather was nice and warm. Then came the trifecta of bad weather: an extended cold snap, high winds for three straight days, and rain (including a hail storm that came with it on May 25) for days on end. Heat units quickly fell far behind normal.
Shook’s test field is minimum-till and received 130 units of nitrogen with a preplant herbicide. He planted 40 acres of FiberMax FM 9063 B2RF treated with N-Hibit Hopper Box Seed Treatment. (N-hibit also is available as an on-seed, dealer-applied treatment.) The remaining seed was not treated with N-Hibit, but all the seed was accompanied in-furrow by Temik at a 41⁄2 lb./A rate. After emergence there were two trips over the field with glyphosate. Shook makes all the applications himself with his own sprayer.
“I think I’ve found the right at-planting nematode combination with Temik and N-hibit,” said Shook. “… I’ve been told that N-Hibit is not a stand-alone product for nematodes, but it seems to give me an edge in combination with Temik; and for now, maybe this is how to get the best out of both. After seeing these results, I’ll expand this nematode management program next year.”

But controlling these nematodes poses a number of dilemmas for growers. Do they use a soil fumigant or spread nematicide on the soil surface? Do some areas need more treatment than others? Because each species prefers a different soil type, and some populations are more intense than others, treatment decisions can be both complicated and costly. Scouting the field by taking soil samples to find those populations is time intensive, and lab analysis of those samples is expensive. Conversely, applying a soil fumigant or a surface nematicide can reduce profits if the grower applies the wrong nematicide or an inaccurate amount.

Several researchers say that the key to nematode management may lie in the soil preference of each nematode species. Since root knot nematodes prefer sand, while reniform nematodes cluster in silty loam, finding the soil types present in a field may help predict locations where nematode problems will occur. To do that, researchers are testing electrical conductivity (EC) systems that analyze soil texture. (A popular example of an EC system is the Veris cart from Veris Industries.) From that analysis, soil-type maps are created.

Louisiana State University nematologist Charles Overstreet uses the maps to identify which places in a field are most likely to house root-knot and reniform nematode populations. “The lower the reading, the more sand in the field,” Overstreet says. “The higher the number, the more clay you have. Once you have clay, you don’t have as many problems with nematodes.”

The maps provide Overstreet and his team – GIS expert Maurice Wolcott, entomologist Gene Burris and plant pathologist Boyd Padgett – with clues about why some areas of the field were unproductive even with nematicide treatments.

“Growers assume the areas of low yield are those where the nematodes are,” Overstreet says. “But low yields may be just from other soil problems, or they may be from nematodes.”

The maps help Overstreet’s team create “management zones” based on soil type. These zones indicate where nematicide may be needed, and where it won’t have any benefit.

USDA soil scientist Dana Sullivan has had similar results in Georgia, where she and University of Georgia researchers Calvin Perry and George Vellidis, Extension Agent Keith Rucker and doctoral student Brenda Ortiz have been testing electrical conductivity measurements since 2005 to locate “hot spots” of root knot nematodes. They use the technology to create homogeneous zones by soil type and other geological variables such as topography and slope.

“Electrical conductivity measurements provide an important key to delineating areas most likely to have high populations of nematodes,” Sullivan says. “For the fields that were not completely infested, we may be able to tell growers, ‘If your field is going to have problems, it is most likely to be here.’”

What is N-Hibit?

The active ingredient in N-Hibit Seed Treatment is harpin protein, which is produced by disease-causing bacteria that attack plants. N-Hibit does not contain pathogens, but the presence of harpin protein turns on internal plant signals that activate natural self defense and growth systems as though the plant was under attack.
Harpin proteins do not enter the plant. They bind with the plant’s external harpin protein receptors, which are present on seed as well as foliage. After binding, the harpin proteins harmlessly disintegrate.
In cotton, according to data from Plant Health Care, Inc., marketers of N-Hibit, growth responses with N-Hibit typically produce increases in root volume and length, plant weight, overall plant vigor and nodes per plant.
The company says N-Hibit complements other nematode management tools.

While using soil EC as a flag to point to potential nematode management zones is a good first step, simply having soils that are favorable for nematodes is not the whole picture. The next questions are: Are nematodes present in these zones? And are the population densities high enough to justify the expense of a nematicide?

Those questions are currently driving the research into this technology. Sullivan’s team is beginning this year to evaluate nematicide rates in each zone. Overstreet, who began testing the EC system for nematode management in 2001, divides the management zones into “verification strips,” half treated with a soil fumigant, and half left untreated as a control area. The strips help validate not only the presence of nematodes in a zone, but also that the pests are the primary cause of any crop loss.

“We still don’t know where the transition zones are; that’s where the verification strips come into play,” Overstreet says. “Some farms we worked with had four or five textures in a field; that makes it very difficult to break it down without knowing where the textures change.”

Captions (3):

Stand damage from the reniform nematode is often
misidentified.

As the name implies, root knot nematodes cause knotty galls
that interfere with moisture and nutrient uptake.

Example of nematode data from a field, broken down into 4 classes.

Leave a Reply

Disease Control / Nematodes Stories

Crop Inputs

EPA Grants Section 18 Label for Topguard Use for Cotton Root Rot in Arizona, Oklahoma

April 28, 2014

The EPA has granted a Section 18 exemption for the use of Topguard fungicide for cotton root rot control in Arizona and Oklahoma.

Crop Inputs

FMC to Acquire Cheminova

September 8, 2014

Auriga Industries has agreed to sell its wholly-owned subsidiary Cheminova to FMC Corporation.

Crop Inputs

New Cotton Webcasts Focus on Irrigation and Foliar Disease Management

July 18, 2014

Two new webcasts focusing on crop protection and irrigation management have been added to the Focus on Cotton online webcast resource, developed by Cotton Incorporated and the Plant Management Network.

Crop Inputs

Watch for Bacterial Blight in Cotton

July 8, 2014

According to the Mississippi State University Extension cotton team, bacterial blight in cotton has been reported in several locations throughout the state.

Crop Inputs

The New Frontier in Nematode Control

July 1, 2014

Researchers at Bayer CropScience say new advances are yielding results in the hunt for nematode tolerant genes.

Disease Control / Nematodes

UGA Cotton Breeder Focusing on Nematode Resistance

June 13, 2014

A University of Georgia cotton breeder's work to develop DNA markers for genes resistant to root knot nematodes is making solid progress.

Cotton Production

Five Keys to Higher Cotton Yields

April 24, 2014

As growers in the Southern Cotton Belt begin shifting their planting focus to cotton, they should consider five optimum pre- and early season opportunities to manage for top yields.

Around The Gin

Product News

PhytoGen Partners with Farmers to Aid Local Charities

October 17, 2014

Since becoming a partner in the Swisher Sweets/Sunbelt Expo Southeastern Farmer of the Year program three years ago, PhytoGen has made donations to 25 charities on behalf of state farmers of the year.

Product News

Enlist Duo Herbicide Approved; Enlist Weed Control System Now Cleared for Use

October 16, 2014

The Enlist Weed Control System from Dow AgroSciences has been approved for field use in corn and soybeans in 2015 by federal regulatory authorities, with introduction in cotton still scheduled for 2016.

News

Registration for 2015 Beltwide Cotton Conferences Opens as Program Takes Shape

October 3, 2014

Registration now is open for the 2015 Beltwide Cotton Conferences, set for January 5-7 at the Marriott Rivercenter in San Antonio, TX.

Product News

October 10 Deadline for Public Comments on Roundup Ready Xtend Crop System Plants

September 25, 2014

The public comment period on the draft environmental impact statement for cotton and soybean plants for Monsanto’s Roundup Ready Xtend Crop System will remain open through October 10.

Cotton Production

New Cotton Webcasts Focus on Using Yield Monitor Data for Precision Planning

September 10, 2014

Two new webcasts to help growers successfully capture and use data from yield monitors have been added to the Focus on Cotton online webcast resource, developed by Cotton Incorporated and the Plant Management Network.

Marketing

First Class Selected for Cotton Research and Promotion Program Hall of Fame

September 8, 2014

Five honorees have been elected to the first class of Cotton Incorporated’s newly-established Cotton Research and Promotion Program Hall of Fame.

Crop Inputs

FMC to Acquire Cheminova

September 8, 2014

Auriga Industries has agreed to sell its wholly-owned subsidiary Cheminova to FMC Corporation.

Crop Inputs

Bayer CropScience Opens New Cotton Research Greenhouse in Memphis

September 4, 2014

Bayer CropScience has opened its newest cotton research facility – a $17 million, 76,000-square foot state-of-the-art greenhouse and headhouse addition to its existing site at Agricenter International in Memphis, TN.

Latest News

Crop Inputs

New Cotton Webcasts Focus on Irrigation and Foliar Disease Management

July 18, 2014

Two new webcasts focusing on crop protection and irrigation management have been added to the Focus on Cotton online webcast resource, developed by Cotton Incorporated and the Plant Management Network.

Crop Inputs

Watch for Bacterial Blight in Cotton

July 8, 2014

According to the Mississippi State University Extension cotton team, bacterial blight in cotton has been reported in several locations throughout the state.

Crop Inputs

The New Frontier in Nematode Control

July 1, 2014

Researchers at Bayer CropScience say new advances are yielding results in the hunt for nematode tolerant genes.

Disease Control / Nematodes

UGA Cotton Breeder Focusing on Nematode Resistance

June 13, 2014

A University of Georgia cotton breeder's work to develop DNA markers for genes resistant to root knot nematodes is making solid progress.

Crop Inputs

EPA Grants Section 18 Label for Topguard Use for Cotton Root Rot in Arizona, Oklahoma

April 28, 2014

The EPA has granted a Section 18 exemption for the use of Topguard fungicide for cotton root rot control in Arizona and Oklahoma.

Cotton Production

Five Keys to Higher Cotton Yields

April 24, 2014

As growers in the Southern Cotton Belt begin shifting their planting focus to cotton, they should consider five optimum pre- and early season opportunities to manage for top yields.

Cotton Production

New Focus on Cotton Webcast Tackles Best Nematode Management Tactics

March 27, 2014

The latest Focus on Cotton webcast from the Plant Management Network and Cotton Incorporated helps pair cotton growers’ situations and needs with the right nematode management practices.

Cotton Production

Climate Corporation Offers Risk Free Trial of Climate Pro Technology

March 20, 2014

Growers who use Climate Basic from The Climate Corporation to capture critical farming and weather data can now try the company’s advanced Climate Pro technologies at no cost through late October.

Crop Inputs

EPA Renews Section 18 Label for Topguard Use on Cotton Root Rot in Texas

January 14, 2014

The Environmental Protection Agency (EPA) has granted a Section 18 exemption of the Federal Insecticide, Fungicide and Rodenticide Act to the Texas Department of Agriculture for the continued use of Topguard fungicide for cotton root rot control. This emergency use

Cotton Production

Protect Your Profits: Safeguard Seed from Nematodes and Disease

December 30, 2013

As 2014 begins, it’s clear that cotton growers will be looking for cost-cutting efficiencies to help them remain productive and profitable, regardless of acreage and/or market prices. Our Cotton Grower editors recently outlined five topics to help growers protect their

Disease Control / Nematodes

Put a Bulls-Eye on Target Spot

July 9, 2013

Sometimes, something different or unexplained just appears – something that leaves even experts scratching their heads. Simply put, that’s target spot. The defoliating disease appeared in South Georgia cotton fields eight years ago as a complete mystery to growers, consultants

Disease Control / Nematodes

Texas Producers Find Root Rot Solutions with Topguard

February 26, 2013

Throughout Texas, cotton growers can finally solve the costly problem of cotton root rot, thanks to the U.S. Environmental Protection Agency’s Section 18 emergency exemption allowing use of Topguard Fungicide. Left uncontrolled, cotton root rot causes direct yield losses of

Disease Control / Nematodes

Arysta LifeScience, Cheminova Form Partnership, Introduce New Fungicide

January 15, 2013

Arysta LifeScience North America, LLC and Cheminova, Inc. have formed a partnership to combine two best-in-class fungicide chemistries through a product that will set the new standard for fungicide performance. Launched under the brand name FORTIX, the product will combine

Disease Control / Nematodes

Eliminating Cotton Root Rot Could Save $20 Million

December 19, 2012

Plaguing 20% of cotton crops in Texas and Arizona, two of the U.S.’s top producing states, Phymatotrichopsis omnivore – also known as cotton root rot – may have met its match. The disease causes approximately $29 million in annual losses

Crop Inputs

EPA Approves Emergency Use of Cheminova Fungicide

October 31, 2012

After a tumultuous growing season overshadowed by drought, the U.S. Enviromental Protection Agency has granted cotton growers access to Cheminova’s TOPGUARD fungicide. For a second year, the EPA has granted Texas cotton growers emergency approval to use TOPGUARD Fungicide to