Feeds:
Posts
Comments

Archive for the ‘Weeds’ Category

Kansas State University Researchers Make Breakthrough Toward Understanding Glyphosate Resistance in Pigweeds

 Article ID: 690983

Released: 12-Mar-2018 6:05 PM EDT

  • Credit: Kansas State University

  • Kansas State University researchers have discovered the mechanism by which weeds develop resistance to glyphosate, an herbicide. Their work could lead to improved weed control strategies and improved production in farm fields and other areas where weeds affect plants and crops. Pictured, left to right, are Mithila Jugulam, Dal-Hoe Koo, Bernd Friebe and Bikram Gill.

Newswise — MANHATTAN, Kan. – Kansas State University researchers have discovered how weeds develop resistance to the popular herbicide glyphosate, a finding that could have broad future implications in agriculture and many other industries.

Their work is detailed in an article that appears in the March 12 edition of the Proceedings of the National Academy of Sciences, known as PNAS and considered to be one of the most-cited journals for scientific research in the world. According to its website, PNAS receives more than 21 million hits per month.

“Herbicide resistance in weeds has been a huge problem, not only in Kansas and the U.S. but many parts of the world,” said Mithila Jugulam, a K-State weed scientist and co-author of the PNAS article.

“What we found that was new was how these weeds have evolved resistance to glyphosate in such a short time. If you look at the evolution of glyphosate resistance in Palmer amaranth, based on our research, it appears to have occurred very rapidly.”

Palmer amaranth and common waterhemp are the two troublesome pigweeds in Kansas agricultural fields, as well as other parts of the United States. Glyphosate – the key ingredient in the popular Roundup brand – is the herbicide that is widely used for controlling many weeds. But Jugulam notes that glyphosate resistance is becoming more prevalent in many states.

“We found that glyphosate-resistant Palmer amaranth plants carry the glyphosate target gene in hundreds of copies,” Jugulam said. “Therefore, even if you applied an amount much higher than the recommended dose of glyphosate, the plants would not be killed.”

Bikram Gill, director of Kansas State University’s Wheat Genetics Resource Center who has worked in plant genetics for nearly 50 years, said the researchers knew pretty quickly that the genetic makeup of resistant weeds was different.

“Normally, the genetic material in all organisms – including humans – is found in long, linear DNA molecules, called chromosomes,” said Gill, another co-author of the study. “But when (K-State researchers) Dal-Hoe Koo and Bernd Friebe, the chromosome experts on the team, looked at these glyphosate-resistant weeds, the glyphosate target gene, along with other genes actually escaped from the chromosomes and formed a separate, self-replicating circular DNA structure.”

Scientists refer to this structure as extra-chromosomal circular DNA (eccDNA). Each eccDNA has one copy of the gene that produces an enzyme that is the target for glyphosate.

“Because of the presence of hundreds of eccDNAs in each cell, the amount of the enzyme is also abundant,” Gill said. “Therefore, the plant is not affected by glyphosate application and the weed is resistant to the herbicide.”

Gill said the indications are that once a weed has acquired eccDNA, the resistance may evolve as quickly as in one generation.

“We think that the resistance via eccDNA is transitory: It can be passed to the weed’s offspring and other related weed species,” he said. “We have somehow caught it in between becoming permanently resistant. Eventually, we think that these eccDNAs can be incorporated into the linear chromosome. If that happens, then they will become resistant forever.”

The same K-State group recently published research on common waterhemp in the scientific journal, Plant Physiology, reporting that “a portion of the linear chromosome containing the target gene broke to form a ring chromosome carrying several copies of the glyphosate target gene,” according to Jugulam.

Armed with their new knowledge, the researchers can begin work on developing strategies to negate resistance in weeds.

“It’s been known that these circular DNA/chromosomal structures can be unstable,” Jugulam said. “What we want to explore is, for example, if we do not apply glyphosate repeatedly or reduce the selection by glyphosate, can we make these ring-structured chromosomes unstable and once again make these plants susceptible to glyphosate.”

The research team notes that farmers should incorporate best management strategies – such as rotating herbicides and crops – to reduce weed pressure: “This may allow evolving resistance to dissipate as we know that these eccDNAs and ring chromosomes are unstable and can be lost in the absence of herbicide selection pressure,” Jugulam said.

“Glyphosate has a lot of good characteristics as an herbicide molecule,” she added. “The recommendations that K-State and many others are promoting is ‘do not abuse glyphosate.’ Use the recommended integrated weed management strategies so that we do not lose the option of using glyphosate for the sustainability of our agriculture.”

Funding for this research was provided in part by grants from the Kansas Wheat Commission; the Kansas Crop Improvement Association; a National Science Foundation grant received through the Wheat Genetics Resource Center; the K-State Department of Agronomy (College of Agriculture); and USDA’s Agricultural Research Service. Kansas State University worked in collaboration with researchers at Clemson University, the USDA Agricultural Research Service (Mississippi) and Michigan State University.

The full article can be accessed on the website for the Proceedings of the National Academy of Sciences.

Read Full Post »

BCPC News

20 November 2017 08:45:04 20 November 2017 08:45:04 |Arable,Machinery and Equipment,News,Products

State-of-the-art weed detection tech could be available within few years

The research collaboration between Bosch and Bayer is helping farms turn digital

The research collaboration between Bosch and Bayer is helping farms turn digital

New technology which will apply state-of-the-art weed detection to apply herbicide more accurately could be available for use by 2020.

As part of a three-year research partnership between two German agricultural and tech giants, Bayer and Bosch are developing smart spraying technology.

Using camera sensors, it can differentiate between crops and weeds and target weeds with pesticides – at lightning speed, in a single process. It is hoped the technology will be available by 2020.

“Smart spraying sustainably clears fields of weeds. This safeguard yields while minimising environmental impact,” Dr. Markus Heyn, member of the Robert Bosch GmbH board of management, said.

The rise of such technology is seen as an important step forward as agriculture leaders advance innovations that are climate-friendly, to reduce the industry’s carbon footprint.

World hunger is also a growing problem for the industry. According to predictions made by the Food and Agriculture Organisation of the United Nations (FAO), farmers will have to sustainably generate around 50% more yield by 2050 in order to feed the global population.

“We want to venture together with Bosch into new territory, combining different technologies to ensure that herbicides are only applied in areas where they are really necessary,” Tobias Menne, head of digital farming at Bayer, said.

‘Field manager’

The technology solution will offer a digital “field manager” which assesses the field and recommends the best time to treat weeds.

Weeds can be difficult to identify, but by using camera sensors, the technology can determine what is growing in the field and then adopt a targeted application technique to spray crop protection agents specifically on weeds.

The multiple camera sensors, which are spread across the entire width of the crop sprayer, take a continuous series of pictures, identifying the different weeds and allowing the optimum treatment to be defined.

While the crop sprayer is still crossing the field, the herbicide is sprayed in the required quantity and mixture using the appropriate application parameters.

While the relevant weeds are targeted, weedless areas remain untouched. All this occurs within milliseconds.

‘Quantum leap’

“Smart spraying is a quantum leap in the fight against weeds,” said Björn Kiepe, head of agronomy at Bayer’s digital farming unit.

“We are combining modern weed identification technology with the ability to apply different active substances as the situation demands. This process is very precise, with a spatial resolution of well under one meter. This will make it even easier for farmers to practice sustainable crop protection.”

Bosch has been transferring its automotive technology to the agriculture industry, and is already generating sales worth 1 billion euros as a result.

By the middle of the next decade, it plans to double sales of technologies for agriculture. “Bosch can do more than cars and cordless screwdrivers. We are bringing high tech to farms, opening up a market worth billions,” said Dr. Markus Heyn.

Read Full Post »

N quensland register

Why integrated weed management is critical

Cropping
WEED MANAGEMENT: Director of the University of Sydney’s Weed Research program Dr Michael Walsh says HWSC plays an important non-chemical role in stopping weed seeds from entering the soil seedbank.

WEED MANAGEMENT: Director of the University of Sydney’s Weed Research program Dr Michael Walsh says HWSC plays an important non-chemical role in stopping weed seeds from entering the soil seedbank.

An integrated weed management approach is essential to manage hard-to-kill weeds, avoid costly, ineffective control measures and preserve the life of herbicide chemistries.

 AN integrated weed management approach that incorporates herbicide and non-
herbicide tools is critical if growers are to manage hard-to-kill weeds, avoid costly, ineffective control measures and preserve the life of important herbicide chemistries.

 

 

University of Sydney’s Weed Research program director Dr Michael Walsh said herbicide resistance was an escalating problem in the northern grain growing region. While growers in Queensland and NSW have traditionally faced fewer problems than their western counterparts, that’s rapidly changing, he said.

Dr Walsh has played an integral role in developing one of Australia’s leading non-herbicide weed management tactics, harvest weed seed control (HWSC), which focuses on the capture and destruction of weed seeds.

“Annual weeds such as ryegrass, wild radish, brome grass and wild oats have adapted to cropping systems, growing to similar heights as cereals and maturing at the same time,” Dr Walsh said.

GRDC VIDEO: Integrated weed management explained.

HWSC plays an important non-chemical role in stopping weed seeds from entering the soil seedbank and can dramatically reduce the emergence of hard-to-kill weeds in the following season.

“It involves collecting, destroying or burning weed seeds that are present at harvest and is particularly effective on problem species such as annual ryegrass and wild radish. There can also be a significant impact on the more difficult to collect species such as black oats, and brome grass.”

A new tool to help growers incorporate HWSC into their weed management program is now available with the release of a GRDC Know More video explaining the use and benefits of HWSC.

“Methods range from something as simple as a chute on the back of the harvester to more complex systems such as a mill system which is integrated into the rear of the harvester,” Dr Walsh said.

“My advice to anyone just starting out is to start simple and assess how HWSC techniques can be effectively incorporated into the management program before advancing to something like the Integrated Harrington Seed Destructor, chaff carts or even a bale direct system.

“By keeping weed seed loads low, growers can greatly reduce the risk of herbicide resistance development, and potentially protect the efficacy of important herbicide chemistries for decades.”

The story Integrated weed management critical | Video first appeared on Queensland Country Life.

Read Full Post »

iot-logo

NZ government funds targeted weeding initiative.

By Stuart Corner on Oct 16 2017 2:53PM

Killer drones coming – for weeds

It’s a vision straight out of a sci-fi movie: a fleet of drones criss-crossing a farm, scanning the ground below for weeds and when they are found zapping them with a laser-beam.

However, the New Zealand government is spending $NZ1 million in the hope of making that vision a reality. The Ministry of Business Innovation and Employment is giving the money to a partnership between government research organisation, AgResearch, the Universities of Auckland and NZ-based technology firm Redfern Solutions to examine the development of such technology.

Program leader Dr Kioumars Ghamkhar said the aim was to use cameras and software to identify the weeds based on their unique chemical signatures and how they reflect light, and then locate them precisely using GPS.

“From there, we think smart spraying (rather than systemic and non-targeted use of chemicals), or the right kind of laser mounted on the drone could hone in and damage the weed,” Ghamkhar said.

“We know there are lasers now available that could be suitable, and that they are extremely accurate, so if lasers are used, it would also avoid damaging the useful plants around the weed.

“The effectiveness of lasers against plants has been tested overseas before but that was in the lab, and we’ll be taking it out in the field to test and see if it works as we have planned.”

There are other initiatives underway suggesting that the weed identification, if not killing, is perfectly feasible.

IoT Hub reported last month that Netherlands-based crop spraying equipment maker Agrifac was a planning to incorporate weed recognition technology developed by French startup Bilberry, in conjunction with Nokia, CETA, Institut Mines-Télécom and Tampere University of Technology into crop sprayers sold in Australia.

Also, Hitachi Australia has developed technology that takes imagery from drone mounted cameras able to respond to a very wide range of wavelengths, analyses this data in the cloud and provides weed identity data to the farmer.

The company is looking to commercialise the service including providing the drone and training in its use to the farmer.

Earlier this year, the Electron Science Research Institute (ESRI) and Edith Cowan University in WA was reported to be close to commercialising a laser system for identifying (but not killing) weeds that used lasers of three different frequencies.

Copyright © IoT Hub, nextmedia Pty Ltd

 

Read Full Post »

       

ftf logo-feed-the-future

IPM IL Logo

iapps-logo1


tuta absoluta

Tuta absoluta in tomato    

Zygogramma beetles

Zygogramma on Parthenium

The International Association for the Plant Protection Sciences (IAPPS) <www.plantprotection.org> and the Feed the Future IPM Innovation Lab at Virginia Tech <http://www.oired.vt.edu/ipmcrsp/> are organizing two symposia at the First International Conference on Biological Control. See details below. We are now soliciting presentations for these two symposia.

Paper submission details

If you have an interest in presenting a paper in either of these symposia, please submit:

  1. Your name and email address:
  2. Title of presentation:
  3. Name(s) of author(s):
  4. Address of corresponding author:
  5. Abstract of no more than 150 words:

Deadline for submission: December 31, 2017

Where to submit your request:

For symposium 1, submit your request to R. Muniappan- rmuni@vt.edu

For symposium 2, submit your request to E.A. Heinrichs- eheinrichs2@unl.edu

Conference and symposia details

Conference title: First International Conference on Biological Control.

Venue: Hotel Le Meridien, Bangalore, India. http://www.starwoodhotels.com/lemeridien/property/photos/index.html?propertyID=1833

Date and time of symposia: September 27 and 28, 2018.

Title of symposia:

  1. Management of Parthenium hysterophorus and other invasive weeds with emphasis on biological control – (Organized by the IPM Innovation Lab)
  2. Management of Tuta absoluta and other invasive arthropods with special emphasis on biological control- (Organized by IAPPS and the IPM Innovation Lab)

Length of presentations: 15 minutes each with 5 minutes for discussion.

 

 

Read Full Post »

sd-logo

Invasive plants change ecosystems from the bottom up

Researcher says Phragmites ‘farm’ their own soil communities

Date:
September 5, 2017
Source:
University of Rhode Island
Summary:
Even when two different Phragmite lineages are grown side-by-side in the same ecosystem, the bacterial communities in the soil differ dramatically. This is a discovery that will aid in understanding how plant invasions get started and the conditions necessary for their success.
Share:
FULL STORY

In a common garden at the University of Rhode Island, Laura Meyerson has been growing specimens of Phragmites — also known as the common reed — that she has collected from around the world. And while they are all the same species, each plant lineage exhibits unique traits.

Now Meyerson, a professor of natural resources sciences, and Northeastern University Professor Jennifer Bowen have revealed that even when two different lineages grow side-by-side in the same ecosystem, the bacterial communities in the soil differ dramatically. It’s a discovery that will aid in understanding how plant invasions succeed and the conditions necessary for their success.

“It’s almost like the different lineages are farming their own microbial communities,” said Meyerson. “What’s amazing is that an invasive Phragmites population in Rhode Island and California will have microbial communities more similar than a native and invasive population living right next to each other in Rhode Island.”

The Phragmites lineage native to North America has inhabited local wetlands for thousands of years, but a lineage introduced from Europe has begun to take over many North American marshes.

“I’m interested in bacteria within salt marshes, but I’ve never thought about these particular plant-microbe interactions and how microbes in the soil work to both facilitate plant success and inhibit growth,” said Bowen. “But it turns out that the evolutionary signatures of the different plant lineages are so strong that it results in similar microbial communities in related plants that are found across the country. And that’s incredible.”

In a research paper published this week in the journal Nature Communications, Meyerson and Bowen outline their field surveys and controlled experiments on native, invasive and Gulf of Mexico lineages of Phragmites. Both methods found that the bacterial communities in the soil are primarily structured by plant lineage rather than by environmental factors, as was previously thought.

“These findings go against the general dogma that says that the environment determines the microbial community you’re going to get,” Meyerson said. “Two populations growing close to each other should have microbial communities more similar than those living farther apart. But our results say that’s not true. In this case for these plants, it’s the plant lineage — below even the species level — that determines the microbial community.”These results are important for understanding more about the success and fitness of invasive species.

“Microbes are really important in terms of determining what happens in a plant community,” explained Meyerson. “By selecting for particular microbial communities, they’re engineering their ecosystem from the bottom up. What happens at the microbial level affects the fitness and chemistry of the plants, and that affects plant interactions.”

The researchers noticed that the microbes associated with the native Phragmites had more kinds of bacteria that are used to defend the plant from enemy attackers than the microbes associated with the invasive variety, which left most of its enemies behind in its native environment.

“The invasive plants didn’t need to cultivate these defense mechanisms among their microbial communities,” Bowen said. “What our research shows is that these plants are successful as invaders, in part, because they are freed from the need to cultivate a microbial defense shield.”

Meyerson said her results provide a new perspective for those managing land and trying to control invasive plants.

“It’s another reason to be cautious about invasive species,” she said. “We have to look beyond what’s going on above ground. We also have to look below at the microbial communities and how they affect ecosystems from the bottom up.”

Story Source:

Materials provided by University of Rhode Island. Note: Content may be edited for style and length.


Journal Reference:

  1. Jennifer L. Bowen, Patrick J. Kearns, Jarrett E. K. Byrnes, Sara Wigginton, Warwick J. Allen, Michael Greenwood, Khang Tran, Jennifer Yu, James T. Cronin, Laura A. Meyerson. Lineage overwhelms environmental conditions in determining rhizosphere bacterial community structure in a cosmopolitan invasive plant. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-00626-0

Read Full Post »

  • Bloomberg

Pesticide ‘Drifting’ Wreaks Havoc Across U.S. Crops

Photographer: Daniel Acker/Bloomberg

Pesticide ‘Drifting’ Wreaks Havoc Across U.S. Crops

‎August‎ ‎1‎, ‎2017‎ ‎4‎:‎04‎ ‎PM‎ ‎CDT ‎August‎ ‎2‎, ‎2017‎ ‎9‎:‎58‎ ‎AM‎ ‎CDT
  • Missouri, Tennessee, Arkansas have placed curbs on dicamba use
  • At least 2.5 million soy acres are impacted, researcher says

Larry Martin in Illinois says he’s never seen anything like it in his 35 years of farming. Arkansas soybean grower Joe McLemore says he faces the loss of his life savings.

They’re among farmers across the U.S. suffering from a pesticide “drifting” across from neighboring fields onto their crops, leaving behind a trail of damage. Although not a new problem, it’s re-emerged with a vengeance this year. At least 2.5 million acres (1 million hectares) have been damaged in this growing season through mid-July, according to estimates from Kevin Bradley, a professor of plant sciences at the University of Missouri.

Dicamba, the offending herbicide, is produced by seed and crop-chemical giants Monsanto Co., DuPont Co. and BASF SE. It’s been around for decades, but in recent years it gained a new lease of life after the companies developed new dicamba-resistant soybean and cotton seeds, allowing farmers to spray crops later in the growing process.

Dicamba is fine if you’re growing those genetically modified varieties, but not if you’re cultivating others and the chemical wafts over from another farm. The situation is so bad that states including Missouri, Arkansas, and Tennessee have placed restrictions on dicamba use at various times during the summer.

Martin, a third-generation farmer, says an 80-acre soybean field of his has been damaged by dicamba. McLemore, who started out on his own eight years ago, after two decades working on someone else’s farm, says 800 of his 1,026 acres of soybeans have suffered damage.

Stunted, Wrinkled

“I’m not really trying to whine or anything, but it’s my life savings on the line every year,” he said by phone.

 McLemore is among a group of growers that have filed a lawsuit in a federal court in Missouri against BASF, Dupont and Monsanto for compensation. Monsanto spokeswoman Christi Dixon said the suit is without merit, while BASF spokeswoman Odessa Hines said it’s reviewing the claim. Dupont spokeswoman Laura Svec said the company hasn’t seen the lawsuit and so can’t comment on it.

Non-resistant crops are left stunted with wrinkled leaves after coming into contact with dicamba. Frustratingly, there’s no way to gauge the impact of yield until the fall harvest, farmers and researchers say. And it’s not always clear where the chemical might have come from — McLemore says that, in his case, he can’t be sure. That leaves farmers angry but also unsure whether to blame neighbors or herbicide manufacturers, said Aaron Hager, a weed scientist at the University of Illinois.

Farmers planted 20 million acres of dicamba-resistant soybeans and 5 million acres for cotton this year, executives at St. Louis-based Monsanto said in a telephone interview Monday. The company attributes the drifting problem to farmers using illegal, off-label products that are more volatile — and thus more prone to drift — than the latest versions of dicamba. They may also be cleaning or using their spraying equipment incorrectly, or applying dicamba when it’s windy, said Robb Fraley, executive vice president and chief technology officer.

Monsanto, which is being acquired by Germany’s Bayer AG, says employees are out in the fields talking to farmers about the problem. Fraley said farmers want better weed-control tools, such as dicamba product, and that the company will learn lessons from what’s happened this season. “There’s always a few challenges in launching new technology,” he said.

Germany’s BASF referred questions on dicamba to a recording of a July 19 media briefing that cited possible explanations for drifting similar to those outlined by Monsanto.

“This year thousands of growers have used these products properly and successfully meeting their challenges with resistant weeds and productivity,” said Svec at DuPont, which has a supply agreement with Monsanto for the herbicide.

The Environmental Protection Agency says it’s reviewing the situation.

“EPA is very concerned about the recent reports of crop damage related to the use of dicamba in Missouri, Arkansas and other states,” an EPA spokesperson said in an emailed statement. “We are working with the states and the registrants to better understand the issue. We are reviewing the current use restrictions on the labels for these dicamba formulations in light of the incidents that have been reported this year.”

While farmers typically look to federal crop insurance for a myriad of issues, problems with dicamba aren’t covered, according to the Risk Management Agency. Country Financial, a farm insurer, based in Bloomington, Illinois, has seen an increase in the number of dicamba-related inquiries, said company spokeswoman Alexandrea Williams. Martin, the Illinois farmer, says he’s not confident his insurance coverage will pay out.

“This is the craziest thing I’ve ever seen,” he said in a telephone interview. “You know you’re going to have a loss of income.”

— With assistance by Jeff Wilson

Before it’s here, it’s on the Bloomberg Terminal.

layVideouseFullscreen

 Sign Up

Read Full Post »

Older Posts »