New Questions Facing Thrips Management

Scott Stewart wants growers and consultants to remember that thrips control matters, especially with some potential issues with thrips management raising questions among researchers.

“I’ve looked at a lot of data in Tennessee, Arkansas and Mississippi,” said Stewart, University of Tennessee Extension entomologist, speaking to a group of consultants in Memphis. “Consistently, we are getting a minimum of 100 pounds yield increase by managing thrips, and, in some cases, you might be able to argue that it’s 200 pounds. It’s too big of a risk to not manage thrips.”

Over the past eight to 10 years, thrips control in cotton has shifted almost entirely to insecticide seed treatments. Long-time cotton growers may always lament the loss of Temik, but the seed treatments have brought their own positives to cotton production.

“We are heavily reliant on seed treatments, primarily imidacloprid and thiamethoxam at a rate of .375 mg of active ingredient,” said Stewart. “Historically, if you look at the data, Temik was better than the seed treatments at reducing the numbers of thrips and providing longer residual control. But it wasn’t reflected in yield. The seed treatments have done just as well at protecting yield, and historically, the difference between thiamethoxam and imidacloprid has been negligible.”

Although thrips management is still in good shape, Stewart points out that some potential control issues have surfaced over the past few seasons – issues that he and other entomologists are continuing to examine closely in their research work. The focus is on three potential reasons for diminished performance – potential plant damage and interference from preemergence herbicide applications, possible degradation of the active ingredients by soil microbes, and decreased susceptibility of thrips to the seed treatments.

“During this timeframe, growers started battling glyphosate-resistant pigweed and increased their use of preemergence herbicides,” said Stewart. “We started seeing more herbicide injury to young plants, which hurt the vigor. And if we also had thrips hurting the vigor, we were getting a double whammy in the field.

“There are definitely times when preemergence herbicides hold back the cotton. They can cause delay and stunting. If you get thrips on top of that, there’s definitely going to be some negative impact.”

The possibility that soil microbes have evolved to the point where they can metabolize the seed treatments and lessen their effectiveness is not unprecedented, pointed out Stewart. It’s happened before with Temik and with several herbicides.

To find out, soil samples were collected and examined. The results to date show that the microbes are having some impact on the active ingredients, but not enough to affect performance.

The real concern lies with diminished performance, and that’s where the majority of testing will focus this year.

“These seed treatments are neonicotinoid insecticides, and those chemistries are used on virtually every crop,” stated Stewart. “Almost 100 percent of our cotton and corn acres in the Mid-South and probably 50 to 75 percent of our soybeans are getting treatments. We are using these products a lot, and there is potential for selection pressure and resistance.

“It’s not likely that thrips have developed resistance, since there are so many hosts for them,” he added. “But whatever it is, it seems to be consistently impacting thiamethoxam more than imidacloprid.”

The primary problem seems to be with tobacco thrips, which make up roughly 81 percent of the thrips population in cotton. Testing was somewhat limited last year, says Stewart, but will expand this year throughout multiple Cotton Belt states.

“We’ll all be involved in trying to figure out how widespread and severe this problem may be,” he said.

So how should growers approach thrips control this year?

“It’s hard to fix a thrips problem after you have it,” stated Stewart. “You have to be proactive.”

He suggests using imidacloprid as the primary seed treatment and adding a foliar application at the 1-2 leaf stage. Imidacloprid still provides enough protection that one foliar application should be sufficient in most circumstances.

For growers who use thiamethoxam, Stewart suggests treating the cotton proactively with a foliar insecticide. Plan for at least two scheduled applications – the first 4-5 days after emergence, followed by the second application a week later. A third application may be needed if thrips populations are high.

“You’ll have to be very aggressive,” he said. “If you are making multiple applications, you might want to consider using Radiant for the second application. And there are a couple of reasons why.

“If you start with acephate, it’s inexpensive and works pretty well on tobacco thrips. But it leaves the Western flower thrips, and they’re harder to kill with acephate. If you come back with Radiant, you can take out those Western flower thrips and are less likely to flare a problem like spider mites or aphids.”

Leave a Reply

Cotton Production Stories
Harvest

Proper Timing of Harvest Aids Focus of New Webcast

July 25, 2016

A new webcast explaining proper timing and use of harvest aids has been added to the Focus on Cotton online series from the Plant Management Network and Cotton Incorporated.

Production Outlook / Acreage

USDA: 10 Million Cotton Acres Planted in 2016

July 1, 2016

USDA’s first acreage report for 2016 shows that U.S. cotton growers have planted 10 million acres in 2016 – a 17% jump above last year's plantings.

Cotton Production

Managing Texas-Sized Growth

July 1, 2016

When his farm operation suddenly doubled in size, Eric Seidenberger did what he knew best – go for it!

Cotton Production

Texas Cotton Crop a Story of Extremes

June 29, 2016

According to Texas cotton specialists, conditions have gone from one extreme to the other for cotton growers around the state.

Planting

Managing Cotton after Uneven Emergence

June 13, 2016

Mississippi State University specialists offer guidelines for managing cotton fields with uneven plant maturity.

Cotton Companion Featured IImage
Cotton Production

Episode 18 – Another Potential Merger Pops Up

May 26, 2016

In the latest podcast, our editors discuss the potential Bayer/Monsanto merger, and Dr. Mike Buschermohle of the University of Tennessee provides his thoughts on how precision ag practices and tools can help cotton growers increase efficiency and save some money.

Planting

Guidelines for Replanting Decisions

May 24, 2016

There are no definitive guidelines for making replant decisions. But a list of factors to consider may help make those decisions a bit easier.

Around The Gin
Product News

Indigo Launches Water Efficiency Product for Cotton

July 26, 2016

Boston-based research firm Indigo has launched its first commercial product – Indigo Cotton – which helps improve the cotton plant’s water use efficiency.

Product News

Enlist Technology Provides Tolerance to Three Key Herbicides

July 13, 2016

The Enlist weed control system will give growers the ability to use three modes of action postemergence in both cotton and soybeans.

Product News

Providing Upland Varieties with Acala-like Quality

July 13, 2016

PhytoGen offers growers several upland cotton varieties with Acala-like fiber quality for added premiums and higher profitability.

Product News

PhytoGen Names Winners in Best Yielder Club Sweepstakes

June 29, 2016

A North Carolina cotton grower was named grand prize winner in the 2016 PhytoGen Best Yielder Club sweepstakes.

Product News

Monsanto Donates Research Center to Local Foundation

June 27, 2016

Monsanto Company has donated its 150-acre Leland Agronomy Center to The B.F. Smith Foundation, a nonprofit organization in the Mississippi Delta.

Product News

Record Yields Set by 2015 FiberMax One Ton Club

May 4, 2016

The 127 members who qualified for the FiberMax One Ton Club pushed cotton yields and quality to higher levels in 2015.

Product News

Meister Media Worldwide Website Relaunches With New Resources

April 22, 2016

Meister Media Worldwide — publisher of Cotton Grower magazine – has relaunched its corporate website, highlighting information and services available from one of agriculture’s leading media companies.

Product News

ReinCloud Promises Remote Control

April 18, 2016

New software set to combine irrigation management and data collection – all in the palm of your hand.

Latest News
Harvest

Proper Timing of Harvest Aids Focus of New Webcast

July 25, 2016

A new webcast explaining proper timing and use of harvest aids has been added to the Focus on Cotton online series from the Plant Management Network and Cotton Incorporated.

Cotton Production

Lessons from the 2011 Drought

July 7, 2016

Years of drought in the Southwest have changed the way cotton producers think about water management.

Cotton Production

More Impact on Cotton Yields from Rotation, Cover Crops

July 6, 2016

After eight years of research on cotton crop tillage, Dr. Paul DeLaune is convinced that yields are impacted more by the cover crop and/or rotation.

Production Outlook / Acreage

USDA: 10 Million Cotton Acres Planted in 2016

July 1, 2016

USDA’s first acreage report for 2016 shows that U.S. cotton growers have planted 10 million acres in 2016 – a 17% jump above last year's plantings.

Cotton Production

Managing Texas-Sized Growth

July 1, 2016

When his farm operation suddenly doubled in size, Eric Seidenberger did what he knew best – go for it!

Cotton Production

Texas Cotton Crop a Story of Extremes

June 29, 2016

According to Texas cotton specialists, conditions have gone from one extreme to the other for cotton growers around the state.

Planting

Managing Cotton after Uneven Emergence

June 13, 2016

Mississippi State University specialists offer guidelines for managing cotton fields with uneven plant maturity.

Cotton Production

Episode 18 – Another Potential Merger Pops Up

May 26, 2016

In the latest podcast, our editors discuss the potential Bayer/Monsanto merger, and Dr. Mike Buschermohle of the University of Tennessee provides his thoughts on how precision ag practices and tools can help cotton growers increase efficiency and save some money.

Planting

Guidelines for Replanting Decisions

May 24, 2016

There are no definitive guidelines for making replant decisions. But a list of factors to consider may help make those decisions a bit easier.

Cotton Production

New Webinar Explains Irrigation Efficiency with Soil Moisture Sensors

May 19, 2016

A new webcast to help improve irrigation practices through the use of soil moisture monitors has been added to the Focus on Cotton online series.

Cotton Production

Cotton Explosion Looming for Kansas?

May 18, 2016

Thanks in part to a new cotton technology, producers in Kansas could be ramping up their cotton acres over the next few years.

Planting

Improved Soil Moisture for Most Texas Cotton Fields

May 4, 2016

Improved soil moisture in most cotton fields in Texas are pushing growth and maturity in early-planted acres and are setting up the state’s northern acres for good planting conditions.

Cotton Production

2016 Georgia Cotton Production Guide Now Online

May 3, 2016

The University of Georgia’s 2016 Cotton Production Guide is now available online.

Cotton Production

University of Georgia Schedules Insect Scout Schools

April 28, 2016

The University of Georgia has scheduled two insect scouting schools in June to provide training for insect monitoring in cotton, peanuts and soybeans.

Planting

USDA Projects 9.56 Million Cotton Acres in 2016

March 31, 2016

USDA’s March 31 Prospective Plantings report projects that U.S. cotton growers will plant 9.56 million acres in 2016 – an 11% increase over last year.