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Wednesday, 21 September 2022 01:02:45

Grahame Jackson posted a new submission ‘Playing the ‘wild card’: Is it possible that some wild potato relatives can help tame zebra chip disease?’

Submission

Playing the ‘wild card’: Is it possible that some wild potato relatives can help tame zebra chip disease?

Potato News Today

A new study led by Texas A&M AgriLife researchers has revealed some resistance to zebra chip disease among certain wild species of potato.

As Paul Schattenberg reports for AgriLife Today, the study of 52 wild potato species — of which one accession was resistant and three were tolerant to the disease — took place as part of an effort to identify novel genetic resistance to the disease, which affects potato production worldwide.

The study, “Identification and Characterization of Potato Zebra Chip Resistance Among Wild Solanum Species,” recently appeared in the scientific journal Frontiers in Microbiology.

The primary investigator for the study was Kranthi Mandadi, Ph.D., a Texas A&M AgriLife Research scientist at the Texas A&M AgriLife Research and Extension Center at Weslaco and associate professor in Texas A&M’s Department of Plant Pathology and Microbiology.

Study co-investigators include Isabel Vales, Ph.D., AgriLife Research associate professor and potato breeder, Bryan-College Station, and Carlos Avila, Ph.D., AgriLife Research associate professor and vegetable breeder, Weslaco, both in the Department of Horticultural Sciences; and Freddy Ibanez, Ph.D., an AgriLife Research scientist at the center and assistant professor in the Texas A&M Department of Entomology

Others involved in the study were Texas A&M AgriLife Research scientists Victoria Mora, M.S., Manikandan Ramasamy, Ph.D., Mona Damaj, Ph.D., and Sonia Irigoyen, Ph.D., at the Weslaco center, as well as Veronica Ancona, Ph.D., a plant pathologist and associate professor at Texas A&M University-Kingsville

Funding for the study was provided through Texas A&M AgriLife’s Insect Vector Diseases Seed Grant Program.

“This type of outcome was precisely what AgriLife Research envisioned when we decided to fund Insect Vector Diseases Seed Grants,” said Henry Fadamiro, Ph.D., chief scientific officer and associate director, AgriLife Research, and associate dean, Texas A&M College of Agriculture and Life Sciences. “We would like to thank the Texas Legislature for funding AgriLife Research’s IVD Exceptional Item Request that has made these seed grants possible. Their continued support is invaluable.”

What is zebra chip disease?

Zebra chip is a complex disease due to its association with the unculturable bacteria Candidatus Liberibacter solanacearum and transmission by an insect vector, the potato psyllid. First reported in Saltillo, Mexico, and subsequently in South Texas, the disease was detected in many other states and commercial potato-growing regions of the world. Left unchecked, it can result in potato yield losses of up to 94%.

Above-ground symptoms of zebra chip-affected plants include purplish discoloration of young leaves, upward rolling of top leaves, the presence of aerial tubers, wilting, stunted growth and plant death.

“Zebra chip-affected tubers are of poor quality, exhibiting vascular ring browning and brown flecks,” Mandadi said. “These chips also have a bitter taste and dark brown striped, zebra-like patterns when fried.”

He said the disease ultimately lowers yield and tuber quality becomes unmarketable.

“If left uncontrolled, the disease can become a significant detriment to potato production.”

Why the study?

The potato is cultivated in over 160 countries and is considered the fourth most important staple food crop after wheat, corn and rice. It is a rich source of carbohydrates and provides other essential nutrients, such as dietary fiber, vitamins, minerals, protein and antioxidants.

“The potato is an important food crop worldwide,” Mandadi said. “As the demand for fresh and processed potato products increases globally, there is a need to manage and control emerging diseases such as zebra chip.”

In Texas, potatoes are grown in all regions that have a significant amount of commercial vegetable production. Commercial acreage for potato production is found in the South Plains, Panhandle and Rolling Plains, as well as the Winter Garden and Rio Grande Valley areas.

“In Texas, we have been dealing with the zebra chip issues for more than 20 years,” Vales said. “Over that time, the disease has become pervasive and has expanded not only in this state but also in other potato-producing states.” 

The bacterium and the insect vector associated with zebra chip disease can also affect other vegetable crops and produce, including tomatoes, peppers and carrots.

Vales said current zebra chip management strategies revolve primarily around controlling the psyllid vector with insecticides or by altering cultural practices, such as timing planting dates to delay exposure to the psyllid population.

“But both of these have only marginal benefits, and while using chemical measures has helped control the psyllid population, this approach is associated with high costs and the potential for increased insecticide resistance,” she said. “That’s why identifying and breeding novel genetic resistance and tolerance to the zebra chip is another important avenue to achieve integrated pest management.”

Vales said previous studies have reported variations in the psyllid’s preference for wild potato species and their breeding clones.

The study results

“For the past four years, our team has been studying approaches to control zebra chip disease thanks to seed funding from projects associated with the Insect Vector Diseases Grant Program,” Mandadi said.

The plant material of 52 wild potato accessions belonging to a Solanum sect. Petota diversity panel, grown from true potato seeds obtained from the U.S. National Plant Germplasm System in Wisconsin, was used in the study.

“New sources of zebra chip resistance were identified among a wild collection of tuber-bearing Solanum species present in the Petota panel,” Mandadi said. “This panel of wild potato is a taxonomically well-characterized and diverse collection from which one can mine for valuable potato traits.”

Several of the 52 accessions were susceptible and moderately susceptible, showing some upward leaf rolling, chlorosis and plant stunting, Mandadi said.

“But following the screening, phenotypic evaluations and quantification of the bacteria in the accessions infected with bacteria-carrying psyllids, we identified one zebra chip resistant accession, Solanum berthaultii, along with three other accessions that were moderately tolerant to zebra chip.”

The three accessions identified in the study as moderately tolerant to zebra chip were S. kurtzianum, S. okadae and S. raphanifolium.

Mandadi’s team also found S. berthaultii has dense glandular leaf trichomes, and this foliar structural modification could be one factor responsible for much of the observed zebra chip resistance.

“The foliar portion produces a sticky substance that seems to trap the psyllid to the plant when it comes in contact with it,” Mandadi explained. “As a result, many psyllids die before reproducing, thus reducing transmission of the bacterium into plants.”

He noted the S. berthautii wild potato accession originated in Bolivia, which is adjacent to Peru, historically identified as the ancestral “birthplace” of the cultivated potato.  

He said S. berthaultii is a promising source for zebra chip psyllid resistance that can be further studied to understand insect resistance mechanisms and incorporated into the potato production system.

“It could possibly be used in breeding new potato cultivars or even as a ‘trap crop’ that can be planted next to more traditional potato cultivars as a way to help eliminate psyllids,” Mandadi said.

He also noted that similar approaches in identifying novel genetic resistance and tolerance in wild plant species could help control other devastating crop diseases, such as potato late blight, citrus greening, Pierce’s disease of grapes and banana wilt.

Source: Texas A&M AgriLife
Author: Paul Schattenberg is a communications and media relations specialist with Texas A&M AgriLife Communications. Based in San Antonio, Paul is responsible for writing advances, news releases and feature stories for Texas A&M AgriLife agencies, as well as providing any media relations support needed. He can be reached here: paschattenberg@ag.tamu.edu or Cell: 210-859-5752; MSTeams: 210-890-4548


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Contribute to CABI’s new Plant Health Cases

Real-life examples of plant health in practice. 

About Plant Health Cases

Fresh green soy plants on the field in spring. Rows of young soybean plants . High quality photo

CABI, together with Editors in Chief Lone Buchwaldt, David B. Collinge, and Boyd A. Mori is embarking on a new type of online publication called Plant Health Cases.

Plant Health Cases will be a curated, peer-reviewed collection of real-life examples of plant health in practice. This will be an invaluable resource for students, lecturers, researchers, and research-led practitioners. We will be developing cases in all areas relevant to plant health, including:

  • plant diseases
  • plants pests
  • weeds
  • environmental factors
  • agronomic practices
  • diagnosis, prevention, monitoring and control
  • international trade and travel

What is a Case Study?

A Plant Health Case is a relatively short publication with a well-defined example of research in plant health, e.g. a study which results in reduced impact from a disease or pest problem. Cases should be between 3000 and 5000 words long, and can include photos, figures and tables. They should be written in an engaging style that is both science-based and accessible using a limited number of references. Importantly, each case should suggest points for discussion to broaden the reader’s horizon, inspire critical thinking and lead to interactions in the classroom or field.

Interested in Contributing to Plant Health Cases?

We are currently looking for contributions of case studies, and we welcome your ideas! You may have existing case study material ready prepared for use in teaching, or a good example of research in plant health which could be easily adapted to our template. For further information and guidance on how to submit your idea for a case study please see here: https://www.cabi.org/products-and-services/plant-health-cases/

Your submission will be peer-reviewed, and a DOI assigned at the time of publication similar to your other scientific publications. The corresponding author will receive £100 upon acceptance of the final case study. 

Publication Plan

We’re aiming to launch Plant Health Cases in mid-2023. Our case studies will offer practical, real-life examples in one easily searchable platform. All users will be able to search, browse and read summaries of case studies. Full text access will be available via individual or institutional subscription, or by purchasing a single case study.

Further Information

Please get in touch with Rebecca Stubbs, Commissioning Editor, CABI

r.stubbs@cabi.org

About CABI

CABI is a not-for-profit, scientific research, international development and publishing organisation. Unlike other publishers, we use our surpluses to support scientific and rural development projects that help improve the lives of the world’s poorest people, which means that by publishing with us, you are helping to improve the lives of some of the world’s poorest people. Please visit our website at www.cabi.org

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SEPTEMBER 14, 2022

Can wild potato relatives help tame zebra chip disease?

by Paul Schattenberg, Texas A&M University

Can wild potato relatives help tame zebra chip disease?
Kranthi Mandadi, Ph.D, a Texas A&M AgriLife Research scientist at the Texas A&M AgriLife Research and Extension Center in Weslaco, was the primary investigator for the new zebra chip-related study. Credit: Texas A&M AgriLife photo

A new study led by Texas A&M AgriLife researchers has revealed some resistance to zebra chip disease among certain wild species of potato.

The study of 52 wild potato species—of which one accession was resistant and three were tolerant to the disease—took place as part of an effort to identify novel genetic resistance to the disease, which affects potato production worldwide.

The study, “Identification and Characterization of Potato Zebra Chip Resistance Among Wild Solanum Species,” appeared recently in the journal Frontiers in Microbiology.

The primary investigator for the study was Kranthi Mandadi, Ph.D., a Texas A&M AgriLife Research scientist at the Texas A&M AgriLife Research and Extension Center at Weslaco and associate professor in Texas A&M’s Department of Plant Pathology and Microbiology.

Study co-investigators include Isabel Vales, Ph.D., AgriLife Research associate professor and potato breeder, Bryan-College Station, and Carlos Avila, Ph.D., AgriLife Research associate professor and vegetable breeder, Weslaco, both in the Department of Horticultural Sciences; and Freddy Ibanez, Ph.D., an AgriLife Research scientist at the center and assistant professor in the Texas A&M Department of Entomology.

Others involved in the study were Texas A&M AgriLife Research scientists Victoria Mora, M.S., Manikandan Ramasamy, Ph.D., Mona Damaj, Ph.D., and Sonia Irigoyen, Ph.D., at the Weslaco center, as well as Veronica Ancona, Ph.D., a plant pathologist and associate professor at Texas A&M University-Kingsville.

“This type of outcome was precisely what AgriLife Research envisioned when we decided to fund Insect Vector Diseases Seed Grants,” said Henry Fadamiro, Ph.D., chief scientific officer and associate director, AgriLife Research, and associate dean, Texas A&M College of Agriculture and Life Sciences. “We would like to thank the Texas Legislature for funding AgriLife Research’s IVD Exceptional Item Request that has made these seed grants possible. Their continued support is invaluable.”

What is zebra chip disease?

Zebra chip is a complex disease due to its association with the unculturable bacteria Candidatus Liberibacter solanacearum and transmission by an insect vector, the potato psyllid. First reported in Saltillo, Mexico, and subsequently in South Texas, the disease was detected in many other states and commercial potato-growing regions of the world. Left unchecked, it can result in potato yield losses of up to 94%.

Can wild potato relatives help tame zebra chip disease?
Potato tubers affected by zebra chip disease are of poor quality, have a bitter taste and display dark brown zebra-like patterns when fried. Credit: Texas A&M AgriLife photo

Above-ground symptoms of zebra chip-affected plants include purplish discoloration of young leaves, upward rolling of top leaves, the presence of aerial tubers, wilting, stunted growth and plant death.

“Zebra chip-affected tubers are of poor quality, exhibiting vascular ring browning and brown flecks,” Mandadi said. “These chips also have a bitter taste and dark brown striped, zebra-like patterns when fried.”

He said the disease ultimately lowers yield and tuber quality becomes unmarketable.

“If left uncontrolled, the disease can become a significant detriment to potato production.”

Why the study?

The potato is cultivated in over 160 countries and is considered the fourth most important staple food crop after wheat, corn and rice. It is a rich source of carbohydrates and provides other essential nutrients, such as dietary fiber, vitamins, minerals, protein and antioxidants.

“The potato is an important food crop worldwide,” Mandadi said. “As the demand for fresh and processed potato products increases globally, there is a need to manage and control emerging diseases such as zebra chip.”

In Texas, potatoes are grown in all regions that have a significant amount of commercial vegetable production. Commercial acreage for potato production is found in the South Plains, Panhandle and Rolling Plains, as well as the Winter Garden and Rio Grande Valley areas.

“In Texas, we have been dealing with the zebra chip issues for more than 20 years,” Vales said. “Over that time, the disease has become pervasive and has expanded not only in this state but also in other potato-producing states.”

Can wild potato relatives help tame zebra chip disease?
The Texas A&M AgriLife-led study involved the assessment of plant material from 52 wild potato accessions. Credit: Texas A&M AgriLife photo by Kranthi Mandadi

The bacterium and the insect vector associated with zebra chip disease can also affect other vegetable crops and produce, including tomatoes, peppers and carrots.

Vales said current zebra chip management strategies revolve primarily around controlling the psyllid vector with insecticides or by altering cultural practices, such as timing planting dates to delay exposure to the psyllid population.

“But both of these have only marginal benefits, and while using chemical measures has helped control the psyllid population, this approach is associated with high costs and the potential for increased insecticide resistance,” she said. “That’s why identifying and breeding novel genetic resistance and tolerance to the zebra chip is another important avenue to achieve integrated pest management.”

Vales said previous studies have reported variations in the psyllid’s preference for wild potato species and their breeding clones.

The study results

“For the past four years, our team has been studying approaches to control zebra chip disease thanks to seed funding from projects associated with the Insect Vector Diseases Grant Program,” Mandadi said.

The plant material of 52 wild potato accessions belonging to a Solanum sect. Petota diversity panel, grown from true potato seeds obtained from the U.S. National Plant Germplasm System in Wisconsin, was used in the study.

“New sources of zebra chip resistance were identified among a wild collection of tuber-bearing Solanum species present in the Petota panel,” Mandadi said. “This panel of wild potato is a taxonomically well-characterized and diverse collection from which one can mine for valuable potato traits.”

Several of the 52 accessions were susceptible and moderately susceptible, showing some upward leaf rolling, chlorosis and plant stunting, Mandadi said.

Can wild potato relatives help tame zebra chip disease?
According to the study, the S. berthautii wild potato accession, shown here, demonstrated zebra chip psyllid resistance. Credit: Texas A&M AgriLife photo by Kranthi Mandadi

“But following the screening, phenotypic evaluations and quantification of the bacteria in the accessions infected with bacteria-carrying psyllids, we identified one zebra chip resistant accession, Solanum berthaultii, along with three other accessions that were moderately tolerant to zebra chip.”

The three accessions identified in the study as moderately tolerant to zebra chip were S. kurtzianum, S. okadae and S. raphanifolium.

Mandadi’s team also found S. berthaultii has dense glandular leaf trichomes, and this foliar structural modification could be one factor responsible for much of the observed zebra chip resistance.

“The foliar portion produces a sticky substance that seems to trap the psyllid to the plant when it comes in contact with it,” Mandadi explained. “As a result, many psyllids die before reproducing, thus reducing transmission of the bacterium into plants.”

He noted the S. berthautii wild potato accession originated in Bolivia, which is adjacent to Peru, historically identified as the ancestral “birthplace” of the cultivated potato.

He said S. berthaultii is a promising source for zebra chip psyllid resistance that can be further studied to understand insect resistance mechanisms and incorporated into the potato production system.

“It could possibly be used in breeding new potato cultivars or even as a ‘trap crop’ that can be planted next to more traditional potato cultivars as a way to help eliminate psyllids,” Mandadi said.

He also noted that similar approaches in identifying novel genetic resistance and tolerance in wild plant species could help control other devastating crop diseases, such as potato late blight, citrus greening, Pierce’s disease of grapes and banana wilt.


Explore further

New variety of zebra chip disease threatens potato production in southwestern Oregon


More information: Victoria Mora et al, Identification and Characterization of Potato Zebra Chip Resistance Among Wild Solanum Species, Frontiers in Microbiology (2022). DOI: 10.3389/fmicb.2022.857493

Provided by Texas A&M University 

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  Grahame Jackson

PestNet

 Sydney NSW, Australia

 For your information

 8 days ago

Soybean virus may give plant-munching bugs a boost in survival

PennState

UNIVERSITY PARK, Pa. — Most viral infections negatively affect an organism’s health, but one plant virus in particular — soybean vein necrosis orthotospovirus, often referred to as SVNV — may actually benefit a type of insect that commonly feeds on soybean plants and can transmit the virus to the plant, causing disease, according to Penn State research.

In a laboratory study, the Penn State College of Agricultural Sciences researchers found that when soybean thrips — small insects ranging from 0.03 to 0.20 inches long — were infected with SVNV, they tended to survive longer and reproduce better than thrips that were not infected.

Asifa Hameed, who led the study while completing her doctoral degree in entomology at Penn State and is now a senior scientist of entomology at Ayub Agricultural Research Institute in Multan, Pakistan, said the findings give key insight into how the virus spreads in plants and affects its insect hosts.

“In addition to prolonging the life of the insects, SVNV infection also shortened the doubling time of soybean thrip populations,” Hameed said. 

 Soybean_vein_necrosis_orthotospovirus

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Scientists sleuth out an elusive plant pathogen in Mexico

For years, scientists and online databases presumed the presence of clubroot—one of the main diseases on cruciferous crops (such as broccoli, cabbage, and kale)—in Mexico. However, no evidence to support this supposition existed until a team of researchers, led by Mauricio Luna and Legnara Padrón-Rodríguez of the University of Veracruz, donned their detective caps to pinpoint the clubroot pathogen.

Since Mexico is the world’s fifth largest broccoli producer and the main supplier to the eastern United States and Canada, determining the pathogen’s presence is important when preparing for potential outbreaks. Legnara Padrón developed the detection methodology during COVID-19, causing the authors to consider what could happen if a future pandemic affects plants. The methodology involved working alongside cruciferous crops growers in Mexico and collecting soil samples from three categories of fields: fields in production, fields without cruciferous crops for up to a year, and fields that had stopped growing cruciferous crops. They were able to extract the clubroot pathogen after growing an array of cruciferous crops plants in the soil collected. Typical clubroot symptoms appeared in the roots of infected plants, and the results were confirmed using molecular methods.

Now researchers can investigate if, as suspected, the clubroot pathogen has hindered the growth of cruciferous crops in certain Mexican fields. New fields affected by the disease have been added to the ClubrootTracker, an online tool developed by Dr. Pérez-López’s group to trace the clubroot pathogen. Additionally, their results will significantly improve the future management of clubroot, safeguarding the cruciferous crops economy in Mexico and the worldwide supply of these important vegetables.

Corresponding author Edel Pérez-López comments that their “results open the door to more exciting research, like studying the genome of P. brassicae Mexican isolates, geographic distribution, and its evolution compared to other North American isolates. The strategy we followed could help detect the clubroot pathogen in other geographic areas, or potentially, other soil-borne pathogens.”

Read the complete research at www.phys.org.

Legnara Padrón-Rodríguez et al, Plasmodiophora brassicae in Mexico: From Anecdote to Fact, Plant Disease (2022). DOI: 10.1094/PDIS-11-21-2607-RE 

Publication date: Wed 14 Sep 2022

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As a grower, you want to have an overview of what’s happening in your crop at all times. This is why many growers make sure that scouting takes place at regular times. Natutec Scout is a tool developed by Koppert to make sure every grower can utilize the benefits of having all your scout data in one central place.

To accommodate growers’ way of working, Natutec Scout offers four different ways to input your data:

  • Pen and paper scouting: write down your observations on paper like you’re used to, and enter your findings straight and simply. Record your findings directly into Natutec Scout using the manual input feature. Input is easier and quicker than using Excel with all the benefits and tools that Natutec Scout provides.
  • Enter your observations on the mobile Natutec Scout app – available for both Android and iOS – in which you make your observations, provide your location, and add notes and photos if you want to add additional findings to your scouting session. This data is then uploaded to the dashboard.
  • Automatic detection of whitefly using the Horiver Scanner: Using the power of Artificial Intelligence (AI) for automatic whitefly counts enables you to save a significant amount of time and labor when counting the whitefly on Horiver cards. Just take a picture of a Horiver card, and you are done.
  • Import historical scout data using the Excel import functionality. You can easily load multiple years of previous scout data (averages and specifics) into Natutec Scout. You immediately get the tools at your disposal to discover trends, hotspots, and other significant events in the IPM of your crop.

The scout data are transferable. Because of that, it’s nice to work with this knowledge between everyone in your company and for your external consultant(s).

For more information:
Koppert Biological Systems
koppert.com

Publication date: Wed 14 Sep 2022

Scouting pests and diseases

As a grower, you want to have an overview of what’s happening in your crop at all times. This is why many growers make sure that scouting takes place at regular times. Natutec Scout is a tool developed by Koppert to make sure every grower can utilize the benefits of having all your scout data in one central place.

To accommodate growers’ way of working, Natutec Scout offers four different ways to input your data:

  • Pen and paper scouting: write down your observations on paper like you’re used to, and enter your findings straight and simply. Record your findings directly into Natutec Scout using the manual input feature. Input is easier and quicker than using Excel with all the benefits and tools that Natutec Scout provides.
  • Enter your observations on the mobile Natutec Scout app – available for both Android and iOS – in which you make your observations, provide your location, and add notes and photos if you want to add additional findings to your scouting session. This data is then uploaded to the dashboard.
  • Automatic detection of whitefly using the Horiver Scanner: Using the power of Artificial Intelligence (AI) for automatic whitefly counts enables you to save a significant amount of time and labor when counting the whitefly on Horiver cards. Just take a picture of a Horiver card, and you are done.
  • Import historical scout data using the Excel import functionality. You can easily load multiple years of previous scout data (averages and specifics) into Natutec Scout. You immediately get the tools at your disposal to discover trends, hotspots, and other significant events in the IPM of your crop.

The scout data are transferable. Because of that, it’s nice to work with this knowledge between everyone in your company and for your external consultant(s).

For more information:
Koppert Biological Systems
koppert.com

Publication date: Wed 14 Sep 2022

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ToBRFV project examines drain water samples, UV cell phone sanitizer, and powdered milk

“Each time we answer a ToBRFV question, three more pop up,” begins Evelien Aussems, a researcher at the ‘Proefstation voor de Groenteteel,’ a vegetable cultivation research facility in Belgium. This ToBRFV practical study – called PraKeTo – coordinator experienced this when the first year full of research concluded.

That was done in partnership with the Proefcentrum Hoogstraten, Scientia Terrae, and the East Flanders Provincial Research Center for Vegetable Production. “Growers keep asking for good hand disinfection methods and eagerly await the arrival of resistant varieties.” With the start of a new four-year research project, the research consortium will try to answer these and other pressing questions around ToBRFV.

Last week, ‘everyone that has anything to do with tomato cultivation’ gathered for an update about the ToBRFV study’s latest findings. The PraKeTo project focused on practical guidance and gathering knowledge about this virus. A group, including growers, was closely involved in the project. “As researchers, we followed up with several growers with infected plants,” says Evelien. At least 15 Belgian farms already have this virus present, while in the Netherlands, there are officially 41.

The PraKeTo discussion drew a full house

Drain water samples
One of the study’s focal points was monitoring via drain water. The idea is that virus detection should be possible before symptoms of infection become visible on the plants and fruit. “Taking drain water samples gives you a better, broader picture than sampling per plant. Then, you’d either have to take samples from all the plants, which is impractical, or you’d have to sample the ‘right’ plants. That’s not so easy to determine, especially at the onset of an outbreak.”

The grower group specifically requested the study, says Evelien. “If a grower hasn’t yet had an outbreak, we can successfully detect the virus in the drain water, and well in time. But what happens to the virus concentrations in the drain water of growers whose plants are already infected?” she had to wonder.

Nine growers already had this virus in their greenhouse, so researchers took bi-weekly drain water samples. They did so after the growers had cleared the greenhouse and, after a time, resumed planting according to all the relevant regulations. “We wanted to get an idea of how the virus concentration in the water evolves in a new crop, with or without a new outbreak. The virus did indeed return to some of the sites, while others were declared virus-free by the Federal Agency for the Safety of the Food Chain (FASFC) six months post-planting.”

This study showed that virus residue can remain in the drain water. “It is thus important not to draw conclusions based on a single water sample. You must monitor the virus concentrations trend over a longer period,” explains Evelien.


ToBRFV contamination leads to poorly colored tomatoes

Distinguishing active and inactive virus
The four-year research project has now begun. Researchers from Proefstation voor de Groenteteelt, Proefcentrum Hoogstraten, and  Scientia Terrae want to further investigate their findings. The researchers also want to further examine the virus residue to determine whether the virus is still active or not.

The B2B project, which stands for ‘Beheersing van ToBRFV op de Belgische tomatenbedrijven’ (‘Controlling ToBRFV on Belgian tomato farms’) allows researchers to do this further research. One of this ongoing study’s goals is to be able to distinguish inactive from active (infectious) viruses. “We learned that, after an outbreak, this virus is present all over. Much of this is probably residue that’s no longer infectious. Clarity about that can give growers a little more peace of mind.”

Researchers will also try to “get to know the virus better,” says Aussems. “We want to use monitoring on farms to do things like map symptom expression, determine the incubation period, and learn more about the spread of the virus. With a new virus, there’s always much to learn.”

Cell phone decontamination
Cell phones were a second major focus of the PraKeTo project. Everyone has one these days, including in the greenhouse. ToBRFV is known to be very tenacious and can survive on surfaces for a long time. So, the thinking is that it can be on phones, too, thus necessitating decontamination methods to be sought there.

“We’ve been researching UV decontamination. We got the idea for that from an experiment. In it, we touched a ToBRFV-infected plant with our hands, then sent a message on our cell phones. We then checked to see how much virus was on the phone. We were shocked to see the sky-high levels of virus concentration,” admits Evelien.

Thus, the search was on to find a way to disinfect cell phones. An American company, PhoneSoap, had developed a technique for this purpose. Evelien describes it as “a box in which you place your phone, where it is hit, on all sides, with UV light. After 15 minutes of exposure, the phone was virus-free.” Growers found this to be too long and thus asked that they try shorter exposures too. “However, five minutes of exposure and disinfection proved too short.”

It is up to each grower, but the best solution would be to keep your cell phone out of the greenhouse, the researcher points out. “Even if you disinfect your cell phone when going into the greenhouse, there’s still a risk, especially if you start using that phone intensively in the greenhouse. Growers, who struggle to ban phones in the greenhouse, can disinfect them. We do that at our test facility station. If you have sufficient time, UV light might be better for your phone’s lifespan than chemicals.”

Powdered milk
The researchers found that disinfecting your hands is a recurring topic among growers, as it was last week. After presenting the year’s first research results, the audience already had new questions. “We even looked at powdered milk as a hand disinfectant. It’s harmless to your skin and is widely used by growers,” says Evelien.

They tested, for example, skimmed powdered milk from the local supermarket. “We dipped our hands in a 5% milk powder solution. After a single dip, we tried to re-infect a plant, and the powdered milk seems to work well.” It is not as straightforward as that, though, and Evelien cautions against drawing hasty conclusions.

The milk powder (temporarily) encapsulates the virus but does not break it down. “After some time, especially at 15 immersions, the powdered milk was teeming with virus concentrations,” she explains. The researchers thus advise growers to replace the powdered milk very regularly. “Otherwise, it becomes a major source of contamination.”

Looking ahead
The new four-year project consists of five so-called work packages. Also, the new study explicitly seeks to connect with other research institutions doing ToBRFV investigations. For example, the European Virtigation project has close links with countries like Israel, where the virus emerged before reaching northwestern Europe.

“Above all, we don’t want to duplicate research,” Aussems points out. Not all five work packages will start simultaneously. The researchers, along with industry stakeholders, including growers, will review the study direction biannually. “It’s vital that what we’re investigating continues connecting to what growers want in practice.”

What is clear, however, is that the researchers have not yet solved the ToBRFV puzzle. The test facility itself became infected last year. “We’ve seen what a huge effect such an infection has. We’re fully committed to finding answers to the many questions.”

“Every day, we get asked, ‘Is this allowed?’, ‘Is that allowed?’ It is a ferocious virus that greatly affects plants and fruits. In the coming years, we want to gather new knowledge about the virus, results with new – resistant or not – varieties, prevention management, and an integrated, post-outbreak approach,” concludes Evelien.

For more information:
Evelien Aussems
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Publication date: Wed 14 Sep 2022

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Nigeria’s Cross River State Cocoa Farms Hit by Black Pod Disease

Sept. 2, 2022 at 1:28 p.m. ET

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By Obafemi Oredein

Special to Dow Jones Newswires





IBADAN, Nigeria–Cocoa farmers in Nigeria’s Cross River state are battling an outbreak of the black pod disease following regular and heavy rainfall the last two weeks, a cocoa industry official and traders said.

“Our farmers are up in arms with their agro-chemicals trying to curtail the black pod disease in their farms caused by incessant rains,” said Sayina Riman, a former president of the Cocoa Association of Nigeria.

Though the rains were beneficial to cocoa by providing moisture and nutrients, he said, “farmers would have to apply chemicals whose cost is always high.”

Cross River state is the largest cocoa producer in Nigeria’s southeast region and the second-largest grower in the country after Ondo in the southwest region, according to Cocoa Research Institute of Nigeria.

The midcrop has been “very poor in the state,” Mr. Riman said. But the 2022-23 main crop cocoa is now being threatened by the black pod at a time when farmers should be getting ready to harvest the crop.

Black pod disease thrives in wet and damp conditions on cocoa farms due to incessant rains without sunshine. It can destroy around 40% of Nigeria’s annual cocoa production if left untreated, officials at the Cocoa Research Institute of Nigeria said.





Write to Barcelona editors at barcelonaeditors@dowjones.com

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AUGUST 19, 2022

Microbes protect a leaf beetle—but for a price

by Daniel Fleiter, Max Planck Institute for Biology Tübingen

Microbes protect a leaf beetle - but for a price
Leaf Beetle. Credit: Max Planck Institute for Biology Tübingen

Insects are known to rely on microbial protection during immobile developmental stages, such as eggs. But despite the susceptibility of pupae to antagonistic challenges, the role of microbes in ensuring defense during an insect’s metamorphosis remained an open question. Scientists from Germany and Panama have now discovered a novel defensive partnership between a fungus and a leaf beetle. The microbe provides a protective layer around the beetle’s pupae and thus prevents predation. In exchange, the beetle disperses the fungus to its host plant, expanding its range. Now published in Current Biology, the researchers present the results of their study.

Antagonistic interactions are widespread in nature, spurring the evolution of protective traits. In insects, as with other animals, symbioses with beneficial microbes can serve as a source of defensive adaptations.

In their study, biologists from the Max Planck Institute for Biology in Tübingen, the University of Tübingen, both Germany, and the Smithsonian Tropical Research Institute, Panama, discovered a mutualistic partnership between the ascomycete Fusarium oxysporum and Chelymorpha alternans, a leaf beetle: The fungus protects the pupae of the leaf beetle against predators. And in exchange, the beetle disperses the fungus to its host plants and thus contributes to its transmission.

“The fungus retained a metabolic profile that reflects its dual lifestyle,” explains Hassan Salem, Research Group Leader at the Max Planck Institute for Biology and senior author of the study. “Our findings show a mutualism ensuring pupal protection for an herbivorous beetle on the one hand, in exchange for symbiont dissemination and propagation on the other hand,” Salem adds.

A microbial dimension to pupal defense

Previous research across numerous study systems described such partnerships with microbes and insects by examining eggs and other juvenile phases. But for the critical pupal stage, the role of microbial protection remained unexplored. And despite birds and some rodents posing threats to pupae, it is rather the smallest predators and parasitoids such as ground beetles, ants and wasps that pursue them in the wild.

“Structural and chemical adaptations are known to protect pupae against predators and other threats. But microbes appear to also play an important role when we consider how a beetle defends itself during metamorphosis,” comments Aileen Berasategui, an Early Career Researcher at the Cluster of Excellence “Controlling Microbes to Fight Infections” (CMFI), University of Tübingen and the first author of the study.

A protective microbial coat

The research team was driven by the observation that a dense microbial growth appears to form at the onset of pupation. Sequence- and culture-based approaches revealed this growth to be Fusarium oxysporum. To understand and demonstrate their hypothesis of a mutual partnership, the researchers performed field studies in Panama while they explored the survival rates of pupae with and without the protective fungus.

Based on follow up investigation using sweet potato plants, the research team further determined that the leaf beetle carries and distributes the fungus to uninfected plants. As the beetles carry the fungus on legs during the adult stage, this resulted in widespread infection of the plants.

The leaf beetle Chelymorpha alternans belongs to the speciose Cassidinae subfamily of leaf beetles. Many members of this group appear to carry the morphological features of the symbiosis with Fusarium oxysporum, the most conspicuous being the microbial coat that covers pupae. When the symbiosis evolved and how it is maintained are central questions that members of this international team hope to uncover.


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More information: Aileen Berasategui et al, The leaf beetle Chelymorpha alternans propagates a plant pathogen in exchange for pupal protection, Current Biology (2022). DOI: 10.1016/j.cub.2022.07.065

Journal information: Current Biology 

Provided by Max Planck Institute for Biology Tübingen

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Penang paddy farmers suffer losses due to bacterial blight

TheStar


  • NATION
  • Wednesday, 10 Aug 202212:22 PM MYT

Azahri Hariff holding up stalks of affected rice plants. BPB has left much of his crop half-filled or empty of grain.

BALIK PULAU: More than 50 rice farmers in the Sungai Burung area here have to bear losses after more than 121ha of rice fields produced half-filled or empty grain, following an attack of ‘hawar bulir bakteria’ (bacterial panicle blight or BPB).

This grim situation has affected the paddy farmers’ income and is even more distressing when it happens when they need money for daily expenses during the post-pandemic recovery phase.

One of them, Azahri Hariff, 44, who cultivates 14ha of rice fields in Sungai Burung said that every season he would spend RM60 thousand on his land to cultivate paddy.

However, when he checked his paddy fields recently, he found that most of the plants were attacked by BPB disease which would affect the production of rice.

“Every rice harvest season, I can produce between 80 and 90 tonnes of rice but this season the production is affected due to the disease.

“I believe that the BPB disease that is attacking the rice fields in the Sungai Burung area is caused by the unpredictable weather changes that are currently affecting the country,” he told Bernama recently.

He added that he was concerned to see the condition of the paddy fields in the area that were attacked by BPB disease and farmers such as himself would suffer losses.

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Azahri hoped that the Ministry of Agriculture and Food Industries could help paddy farmers whose income was affected by the disease.

Another rice farmer in Sungai Burung, Talib Hamid, 70, claimed that this season he only managed to harvest five tonnes of rice from his 2.02 hectare of land, compared with the usual 15 to 16 tonnes.

Talib said that this was the first time his paddy was attacked by the disease which affected his rice yields. – Bernama

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TAGS / KEYWORDS:Paddy Field , Rice , Sungai Burung , Disease ,  Hawar Bulir Bakteria ,  Bacterial Panicle Blight ,

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Japanese growers use drones to check vegetables from the sky

Near the city of Tokyo, Japanese growers are checking on their vegetables from the sky, by using drones. Kamiya Yuki works his fields in Tokorozawa City, Saitama Prefecture. He used a drone on Tuesday to check on his field of about 8,000 square meters.

Kamiya says it’s hard to check the central part of the field without a drone because the crop grows to about the height of a person at this time of the year. That is why he found the device very effective for quickly identifying possible diseases and checking on growth conditions.

The city provides subsidies to farmers to use drones. It wants to help them shift to smart agriculture by using the latest technologies. Around 10 farmers in the city have plans to use drones this year.

Source:  www3.nhk.or.jp

Publication date: Wed 24 Aug 2022

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