Archive for the ‘Control tactics’ Category

Friday, 06 May 2022 07:36:00 PestNet

Grahame Jackson posted a new submission ‘Why Tomato Crops Today Are So Susceptible to Disease ‘


Why Tomato Crops Today Are So Susceptible to Disease

Growing produce

Anthony P. Keinath By Anthony P. Keinath|May 4, 2022

Why are tomatoes so susceptible to disease? Of three possible answers — aggressive pathogens that specialize on tomato, the tomato plant itself, or the growing environment — it’s not the pathogens.

For example, early blight and late blight can be equally destructive on tomato and potato. Phytophthora blight and fruit rot is worse on pepper than tomato. Is there something about the tomato that makes it inherently susceptible, something medical doctors call a congenital defect? Or is it weather conditions during the growing season? The answer seems to be both.

Same Chromosome Controls Resistance and Size

Tomatoes were domesticated in Southeast Mexico from a wild tomato that resembles a small cherry tomato. The cherry tomato ancestor originated in the humid Amazon rainforests of Northeast Peru and then spread to the Yucatan Peninsula of Mexico, according to a 2020 article in the highly regarded scientific journal Molecular Biology and Evolution.

San Martin, Peru, where ancestral tomatoes still grow wild, is humid with 6 to 13 inches of rain per month, year-round. So, tomatoes should be suited to cropping in humid environments.

But something happened in the chase for larger fruit. Early Mesoamericans who domesticated tomato, as well as modern plant breeders, produce buyers, and consumers wanted large tomato fruit. The average size of a fruit doubled as tomato developed into what passes for an early modern tomato.

Bacterial spot is one of multiple tomato pathogens to be aware of. Susceptibility is linked to genes for large fruit and high yield.
Photo by Zack Snipes

Unfortunately for today’s tomato growers in the Eastern U.S., large-fruited tomato plants are susceptible to a variety of bacterial diseases. That includes bacterial wilt and bacterial spot.

The genes in wild tomatoes that make them resistant to bacterial diseases are found on the same chromosome as genes that control fruit size and yield.

That’s why the resistant offspring of a cross between a tomato parent with decent-sized fruit (but susceptible to bacterial diseases) and a resistant parent (but with small fruit) always have fruit that are too small for current tastes.

Allow Breathing Room

Another likely reason for the prevalence of tomato diseases is our modern, intensive production practices.

Most staked tomatoes are grown with 6 feet between rows and 2 feet between plants. That’s tight spacing for full-grown tomato plants, even after “suckering” to leave only two main side branches.

The large fruits — unlike the original cherry-sized fruits — are too heavy for tomato plants to support without aid from the stake-and-tie production system that originated in the Southeast.

Stringing a mass of foliage together creates humid microclimates perfect for pathogens. On humid summer days, or after a downpour, the inner leaves of the canopy may never dry completely. Continuously wet leaves allow bacteria, fungi, and water molds like late blight to grow continuously — just like they do in a petri dish in the lab.

Simply giving tomatoes more space may be enough to reduce foliar diseases.

A local organic grower spaces tomato rows 12 feet apart instead of the standard 6 feet. This farm had less bacterial spot than nearby conventional farms.

He sprayed the recommended organic products, copper plus Serenade (Bayer Crop Science), while conventional growers sprayed the recommended conventional products, copper plus mancozeb. Both spray programs are moderately effective, so one likely reason for seeing less bacterial spot on the organic crop was the wider row spacing.

Protect Plants from Rain

High moisture in the form of rainfall also damages tomatoes. The processing tomato industry is concentrated in California’s Central Valley. Rainfall there is only five to 20 inches per year. That’s half the annual precipitation in the Midwest, where processing tomato acreage has declined since the 1990s.

One way to protect tomatoes from too much rain is to grow them under high tunnels. Based on a trial at Kansas State, tomato fruit from high tunnels had less postharvest fruit rot and could be stored longer than field-grown tomatoes.

The high tunnel environment also reduces gray leaf spot on the very susceptible heirloom ‘Cherokee Purple’.

In Florida, fruit cracking and decay of beefsteak tomato was consistently two-thirds lower in high tunnels than in the field.

In both locations, the plastic covering of the high tunnel keeps the leaves and fruit dry during rain and protects them from rain-splashed pathogen spores.

Although wild tomato is native to the humid tropics, modern descendants perform better in drier natural or man-made environments.

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MAY 2, 2022

Organic pesticides to provide natural protection for endangered crops

by Vittoria D’alessio, Horizon: The EU Research & Innovation Magazine

Organic pesticides to provide natural protection for endangered crops
The iconic European olive crop is in urgent in need of a biopesticide solution to fight the Xylella fastidiosa bacterium,. Credit: © Fabio Michele Capelli, Shutterstock

Some vitally important European crops like vines and olives are being devastated by disease. Scientists are searching for biological replacements for chemical pesticides to improve crop and human health.

The threat to agriculture from invasive species is huge. The United Nations (UN) estimates that plant disease costs the world’s economy over €200 billion per year, with 20–40% of crop production lost to pests.

“The economic loss from invasive species is immense, and if we took no action, there would be a huge amount of food insecurity, not only across the EU but across the globe,” said Dr. Hikmate Abriouel, professor of microbiology at Universidad de Jaén in Spain’s Andalucía.

With the stakes so high, it’s easy to understand why the agricultural sector is one of the largest users of chemicals worldwide.

The question of food security is uppermost these days. But, as Dr. Abriouel goes on to explain, our growing reluctance to use chemicals in agriculture adds a layer of complication to farming.

“There was a time when it was normal to rely on powerful pesticides to treat agricultural land,” she said. “But now we know that a chemical designed to kill a living organism is likely to have negative impacts on other biological systems too.”

Spraying crops with synthetic compounds has adverse impacts on people, farm animals, wildlife, pollinators like bees and other living things that play an essential role in the ecosystem. The chemical runoff also damages the land and water.

Pollution risk

Pesticide pollution causes risk to farmland from the chemical residues that leach into water supplies.

Some synthetic pesticides have been linked to human diseases like cancer, diseases of the immune system and respiratory illnesses.

Farmers who work with pesticides are particularly vulnerable to side-effects, with an estimated 44% of farm workers worldwide experiencing at least one incident of acute pesticide poisoning every year.

The EU’s Farm to Fork (F2F) strategy for sustainable food production targets significant reductions in the use of chemical pesticides, fertilizers and antimicrobials and supports an increase in organic farming. Sustainability goals mean biopesticides or biological alternatives to pesticides are required.

“There is a lot of evidence that replacing chemicals with biopesticides works with nature rather than against it,” said Dr. Abriouel. Biological solutions benefit soil health and biodiversity too.

Dying vines

In France alone, around 12% of vineyards were unproductive between 2012 and 2017 due to Grape Trunk Disease (GTD) which has been spreading across Europe over the past two decades. A chemical pesticide used to treat vines was banned because it is harmful to human and environmental health.

The disease results in 50% less productive plants, a decrease in the quality of the wine and the premature death of healthy vines. Worldwide, estimates for the replacement cost of grapevines exceed €1.4 billion per year.

As a response to this blight, the EU is funding the multinational BIOBESTicide project which aims to find a biological solution to GTD.

“Our aim is to produce a really effective, totally natural preventive solution to this very serious and very expensive problem,” said Dr. Assia Dreux-Zigha who works for the French biotechnology company Greencell and is coordinating the BIOBESTicide research.

The team’s research is focused on a specific strain of Pythium oligandrum—a “friendly” fungus that is naturally present in the rhizosphere of many crop plants, including vines. The rhizosphere is the microorganism-rich region of soil directly around a plant’s roots.

P. oligandrum works both by destroying parasites directly and by inducing plant resistance against further attack. After isolating P. oligandrum in the lab, Greencell and its partners found that under certain conditions, the biopesticide colonized the roots of vines and stimulated the plant’s natural defenses against GTD.

In the near future, following trials and safety approval, the BIOBESTicide researchers aim to scale up and field-test their biopesticide in vineyards across different geographical areas.

“This is a very challenging project but, when we finish in late-2023, we hope to have a solution that will make it possible for vine plants to survive for their entire natural lifecycles,” said Dr. Dreux-Zigha.

Undoubtedly, winemakers will raise a glass to this prospect.

Olive preserver

A second iconic European crop urgently in need of a biopesticide solution is the olive. First detected in European olives in 2013, Olive Quick Decline Syndrome (OQDS) is the disease caused by the bacterium Xylella fastidiosa.

In Puglia, southern Italy, where Xylella first surfaced on the continent, olive production shrank by 65–80% in the years up to 2020 with the loss of an estimated 100,000 jobs and the destruction of 400-year-old heritage olive trees.

Xylella has surfaced in France, Spain and Portugal, spread by an insect called the spittlebug. Affected plants are infected from the roots upwards, causing the leaves to turn brown and eventually killing the plant. It is considered one of the most dangerous plant pathogenic bacteria in the world.

“The problem with this pathogen is getting worse,” said Dr. Abriouel, who supervises the EU-backed SMART-AGRI-SPORE project, which aims to develop a biopesticide based on bacterial spores.

“Preventing further spread of this pest is a priority in the EU,” she said. A 2020 study estimated that as a worst-case scenario, Italy alone stands to lose between €1.9 billion and €5.2 billion over a 50-year period as a result of OQDS.

A number of projects are developing biopesticides to attack Xylella. Principal researcher Dr. Julia Manetsberger under the supervision of Dr. Abriouel is focused on modifying a strain of another bacteria to render it deadly to Xylella.

The researchers are hopeful that by 2024, a viable biopesticide will emerge from this research.

“We can’t use something against Xylella that changes the biodiversity or destroys or increases the resistance of microorganisms present in other plants and soil,” said Dr. Abriouel. “In other words, we can’t solve one problem and create another.”

“We are working hard to reach this objective,” said Dr. Manetsberger, “These plants are so important for our economy and we need to defend them.”

Explore further

France reports first case of fatal olive tree bacteria

Provided by Horizon: The EU Research & Innovation Magazine 

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‘Almost all crops today have been changed from their original form’: National Academies of Sciences says GMOs just most recent form of food genetic modification

National Academies of Sciences Engineering and Medicine | May 3, 2022

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Credit: Mary Evans Picture Library
Credit: Mary Evans Picture Library

This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation. It is posted under Fair Use guidelines.

People have been changing plants for thousands of years. Humans started farming more than 10,000 years. Agriculture began in Mesopotamia, in the region we now call the Middle East. At first, people took the seeds of wild plants and put them in places where they would grow well and be easier to harvest. Soon, people noticed that some plants performed better than others, and they kept the seeds of the best ones to plant the next year. As people did this year after year, farmed crops slowly became different from their wild relatives. This process is often called domestication.

The choices early farmers made about which seeds to plant were driven by many of the same factors that influence choices made about seeds today. Many wild plants naturally produce toxins that act as a defense against pests, and people made seed choices so that many crops today are tasty, nutritious, and easy to digest. Farmers want plants that are easier to harvest and produce more fruit, vegetables, grains, fiber, or oil. They also look for plants that can withstand disease, pests, flooding, drought and other problems.

Over thousands of years, people grew many types of crops, brought them to new areas of the world, and continued to change the plants to suit their needs.

Methods for changing plants expanded as science and technology advanced

In the 1800s, Gregor Mendel and others made discoveries about how parents pass traits to their offspring. This new understanding helped people produce new varieties of plants with useful qualities using selective breeding. In this method, two plants with desirable traits are deliberately mated so the next generation of plants will have these characteristics. As experiments in plant breeding continued, people learned how to breed plants together to create hybrids with certain traits. For example, hybrid types of corn, wheat, and rice were bred that produce more grain per plant and that can be grown in narrow rows in a field. Farmers are then able to harvest more grain using the same amount of land.

In the 1930s, people found that applying radiation or chemicals to a seed caused plants to have traits different from their parents. This is because radiation and certain chemicals can cause changes in the genes of plants, which determine what characteristics the plant will have. The seeds with the most useful traits caused by these genetic changes were then grown and used to breed new varieties of crops. Today, hundreds of varieties of more than 100 crops that we grow and eat were developed using these means, including many types of rice, wheat, and barley.

With the discovery of the structure of DNA in 1953 and other advances in understanding how genes work, scientists began to explore other ways to improve plants. By the 1980s, scientists were able to identify specific bits of DNA called genetic markers that are associated with particular traits. By knowing what genetic markers to look for, marker assisted breeding speeds up the breeding process by allowing scientists to know whether a plant will have the desired trait even before it is grown.

For most of history, improving plants depended on choosing two parent plants of similar types or varieties that are able to breed with each other. In the 1980s, scientists also invented ways to create new traits by combining the genes of different kinds of plants, as well as DNA from other organisms, including bacteria and viruses. These new plants carry “recombinant” DNA and are sometimes referred to as Genetically engineeredtransgenicgenetically modified organisms (GMOs), or bioengineered. More than a dozen food crops with traits introduced through recombinant DNA are grown in the world today.

In the 2010s, gene editing was developed, allowing scientists to directly change a plant’s genes without having to use the DNA from another plant or other organism. A few such crops are grown today, including gene-edited soybeans that produce soybean oil with a healthier balance of fats.

Almost all crops today have been changed from their original form

Since people have been farming for such a long time, nearly all crops grown today have been genetically improved, whether through domestication, selective breeding, hybridization, radiation or chemicals, or changes made directly to plant genes by humans.

Scientists and growers continue to improve methods for making crops with certain traits. For example, people are working to create crops that can better withstand droughts, which are becoming more common as the climate changes.

A version of this article was posted at National Academies of Sciences, Engineering, and Medicine and is used here with permission. Find the National Academies of Sciences on Twitter @theNASciences

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Insect-resistant GMO cowpea trials wow Nigerian farmers with jumping yields and lower costs — but other farmers remain hesitant

Abdulkareem MojeedEbuka Onyeji | Premium Times | May 4, 2022

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Credit: IFAD
Credit: IFAD

This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation. It is posted under Fair Use guidelines.

Last August, the farmers were given cowpea seeds genetically modified (GM) to resist the destructive pod-borer insect pest and improve yield to experiment on their farms.

Mr Osondu said his farm became the centre of attraction a few weeks after he planted the cowpea. “As you can see, I planted the beans at a roadside where everybody can see it,” the farmer said. He was quick to point out the sharp contrast between the traditional cowpea the farmers are used to and the new variety.

“I used to spray insecticides at least five times on the normal cowpea yet the crop will still be eaten by insects before harvest. But this one I sprayed only once, and it did very well. I harvested about two months after planting and the yield was impressive.

“They gave me half a cup and I harvested three painter buckets. If I planted the same amount of normal beans, I would have harvested only one painter,” the farmer said.

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Poor awareness of GMO among not just lay people but even many informed Nigerians fuels scepticism, which is making it difficult for Nigerians to make informed decisions on whether to accept or reject GM cowpea in Nigeria, our findings revealed.

This is an excerpt. Read the original post here

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How plant breeding innovations are helping feed a hungry world

Mikaela Waldbauer | Sustainable Agricultural Innovation & Food (SAIFood) | April 29, 2022

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Rice can survive submerged, but not for long. Plant breeding technology is getting the crop ready for climate change floods. Credit: Sasin Tipchai
Rice can survive submerged, but not for long. Plant breeding technology is getting the crop ready for climate change floods. Credit: Sasin Tipchai

This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation. It is posted under Fair Use guidelines.

As of 2019, nearly 26% of the globe’s population “experienced hunger or did not have regular” access to safe and nutritious food (FAO, 2020). With increasing global populations and a changing climate, this number is estimated to surpass 840 million by 2030 (UN, n.d.).

Plant breeding technologies have impacted global food security in positive ways. One of the major ways genetically modified (GM) crops can influence global food security is by adapting plants to the changing climate. Plant breeding can be utilized to develop crop plant varieties with a higher tolerance to environmental stresses such as heat, drought, and flooded conditions.

For example, a rice variety developed by plant breeders in Bangladesh has been shown to survive flooded conditions for as long as two weeks, and common beans have been used to develop both heat and cold resistant varieties capable of being grown in both the Durango region of Mexico and the high altitudes of Columbia and Peru (Global Partnership Initiative for Plant Breeding Capacity Building [GIPD], n.d.).

The climate is changing at a faster rate than crop plants can adapt, and few solutions to this issue exist. One key solution is the improvement of crop plant varieties through new plant breeding innovations. The evidence is clear that GM crop varieties are superior in performance under harsh conditions (GIPD, n.d.). However, these solutions are not utilized to their fullest extent due to intense scrutiny and rejection.

Importance of nutritious diets

With an increase in the global population, food insecurity is predicted to rise. To compensate for population growth, food production must increase at a faster rate than it currently is today. Research shows plant breeding can address this concern. According to a 22-year study on the economic impact of GM crops, global production has increased substantially because of yield increased from GM crops (Brookes & Barfoot, 2020). Urbanization is reducing the area of arable land available for food production. Without the use of additional land to grow more food, an increase in yields on the land currently cultivated will be solely relied on to increase production. GM crops are one tool that can be used in improving production levels of food, when compared to conventional crops, by increasing yields.

Considering smallholder farmers make up 50% of the world’s undernourished (Qaim & Kouser, 2013), increasing the profit of smallholder farmers should have a net decrease in food insecurity in developing countries. Smallholder profits have also increased with the adoption of GM crops. Studies have found that GM crop varieties have improved yields substantially when compared to conventional crops. Most notably, the highest improvements in crop yield have been observed in developing countries, where food insecurity is the highest (Brookes & Barfoot, 2014). Since the study began in 1996, there has been a $225 billion increase in farmer income, as of 2018. A reduction in pesticide cost and improvement in yields is responsible for increased profit, primarily through insect-resistant varieties such as the newly commercialized Bt cowpea in Nigeria. An increase in farmer profit through GM crop cultivation is clear, especially in low-income countries. Yet, the very regions that could benefit most from these crops are the ones that reject them. More widespread commercialization of GM crop varieties has the impact to increase farmer profit, specifically smallholder profit, which makes up a generous portion of the world’s undernourished.

Micronutrient deficiency affects over 50% of the global population (Nestel et al., 2006). Large consumption of staple food products in developing countries such as rice, wheat, and corn with little variety can lead to nutritional deficiencies including deficiencies in vitamin A, iron, zinc, among others. Recently, a GM rice crop biofortified with beta-carotene (a vitamin A precursor) was approved for cultivation in the Philippines, called Golden Rice. Golden Rice has the potential to diminish the prevalence of micronutrient-related malnutrition, vitamin A deficiency. Golden Rice can combat vitamin A deficiency in high rice-consuming regions by allowing the consumption of beta-carotene without changing the taste or agronomic qualities of the rice while remaining at a comparable cost to conventional rice (IRRI, n.d.). Evidence does depict the capabilities of biofortification in a deficient diet.

Looking forward

Of the opposing views brought forth by ant-GMO advocates, most are refutable. Sifting through the scientific literature, is it suggested that while GM crops may offer a net positive impact on the state of global food security, they are not a panacea to the enormous problem of global food insecurity. Rather, GM crops can be viewed as one vital tool assisting in the mitigation of global food insecurity.

Mikaela Waldbauer is an Agronomy student at University of Saskatchewan interested in food security and plant breeding. Follow Mikaela on Twitter @Mikaela_Marion

A version of this article was posted at Saifood and is used here with permission. You can check out Saifood on Twitter @SAIFood_blog

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Newly Discovered Protein in Fungus Bypasses Plant Defenses


ARS News ServiceSunflower plant infected with Sclerotinia head rot.
A newly discovered protein helps the fungus that causes white mold stem rot in sunflowers and more than 600 other plant species bypass the plants’ defenses. Newly Discovered Protein in Fungus Bypasses Plant Defenses For media inquiries contact: Kim Kaplan, 301-588-5314 Pullman, Wash., April 25, 2022

A protein that allows the fungus that causes white mold stem rot in more than 600 plant species to overcome plant defenses has been identified by a team of U.S. Department of Agriculture Agricultural Research Service and Washington State University scientists.Knowledge of this protein, called SsPINE1, could help researchers develop new, more precise system of control measures for the Sclerotinia sclerotiorum fungus, which attacks potatoes, soybeans, sunflowers, peas, lentils, canola, and many other broad leaf crops. The damage can add up to billions of dollars in a year of bad outbreaks.S. sclerotiorum fungi cause plants to rot and die by secreting chemicals called polygalacturonases (PG), which break down the plant’s cell walls. Plants evolved a way to protect themselves by producing a protein that stops or inhibits the fungus’ PG, labeled PGIP, which was discovered in 1971. Since then, scientists have known that some fungal pathogens have a way to overcome plant’s PGIP. But they had not been able to identify it.”What you have is essentially a continuous arms race between fungal pathogens and their plant hosts, an intense battle of attack, counterattack and counter-counterattack in which each is constantly developing and shifting its chemical tactics in order to bypass or overcome the other’s defenses,” said research plant pathologist Weidong Chen with the ARS Grain Legume Genetics Physiology Research Unit in Pullman, Washington, and leader of the study just published in Nature Communications.The key to identifying SsPINE1 was looking outside the fungi cells, according to Chen.”We found it by looking at the materials excreted by the fungus,” he said. “And there it was. When we found this protein, SsPINE1, which interacted with PGIP, it made sense.”Then to prove that the protein SsPINE1 was what allowed Sclerotinia to bypass plants’ PGIP, Chen and his colleagues deleted the protein in the fungus in the lab, which dramatically reduced its impact.”I got goosebumps when we found this protein,” said Kiwamu Tanaka, an associate professor in Washington State University’s Department of Plant Pathology and a co-author on the paper. “It answered all these questions scientists have had for the last 50 years: Why these fungi always overcome plant defenses? Why do they have such a broad host range, and why are they so successful?”The discovery of SsPINE1 has opened new avenues to investigate for controlling white mold stem rot pathogens, including possibly even more effective, more targeted breeding to make plants naturally resistant to sclerotinia diseases. And the team has showed that other related fungal pathogens use this counter-strategy, which only serves to make this discovery even more important.This research is part of the National Sclerotinia Initiative, a multiorganization effort that ARS created to counterattack S. sclerotiorum because the fungus does so much damage around the world.The research team also included scientists from USDA-ARS, WSU, Northwestern A&F University in Shaanxi, China, Wuhan Polytechnic University in Wuhan, China and Huazhong Agricultural University in Wuhan.The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.
Interested in reading more about ARS research? Visit our news archiveU.S. DEPARTMENT OF AGRICULTURE
Agricultural Research Service

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Study Uses Carbon Black as an Alternative to Insecticides

Apr 19 2022Reviewed by Bethan Davies

The yellow fever mosquito was only found in Africa before being unintentionally introduced to the New World by the slave trade in the 16th century. It has since become an invasive species in North America due to its adaptability.

Study Uses Carbon Black as an Alternative to Insecticides.
Image Credit: Shutterstock.com/Digital Images Studio

But researchers at The Ohio State University believe they have discovered a way to eradicate the pesky population in its juvenile stages.

The current study published in the journal Insects describes how mosquitoes have evolved natural resistance to some chemical insecticides and propose carbon black, a type of carbon-based nanoparticles, or CNPs, as an alternative.

Peter Piermarini, a co-author of the study and an associate professor of entomology at Ohio State, described CNPs as “microscopic” materials made of organic elements. Emperor 1800, a tweaked version of carbon black that is commonly used to coat automobiles in black, was used in the study.

Despite the fact that CNPs are a comparatively new scientific development, they have been regarded as a crucial tool for controlling various insect and pest infestations, according to Piermarini.

If we can learn more about how carbon black works and how to use it safely, we could design a commercially available nanoparticle that is highly effective against insecticide-resistant mosquitoes.

Peter Piermarini, Study Co-Author and Associate Professor, Entomology, The Ohio State University

The yellow fever mosquito, also known as Aedes aegypti, is a mosquito species that spread diseases such as dengue fever, Zika virus and chikungunya fever. Adults rarely fly more than a few hundred meters from where they appear, but their abundance allows diseases to spread at a steady rate, killing tens of thousands of people each year and hospitalizing hundreds of thousands more.

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As a result, the mosquito is regarded as one of the most lethal animals on the planet. The goal of this research was to determine how toxic these nanomaterials might be to mosquito larvae or the insect’s immature form.

Not all mosquitos are interested in making blood their next meal. Male mosquitoes consume flower nectar, while female mosquitoes consume both flower nectar and blood to provide enough protein for their eggs to grow.

Female mosquitoes revert back to standing pools of water, such as birdbaths or lakes, to lay their eggs. These larvae will stay in the water for about a week after hatching until they reach adulthood and take flight.

To see if Emperor 1800 could stop this process, investigators used two distinct strains of yellow fever mosquitos in the laboratory, one that was extremely susceptible to chemical insecticides and the other that was extremely resistant.

The researchers introduced the carbon black nanomaterials to the water during the early stages of the mosquito’s life cycle and checked in 48 hours later. They were thus able to ascertain that CNPs kill mosquito larvae both efficiently and swiftly.

Given the properties of carbon black, it has the most potential for killing larvae because it can be suspended in water,” Piermarini adds.

The observations revealed that the material was accumulated on the mosquito larvae’s abdomen, head and even in its gut. This indicates that the larvae were consuming smaller particles of carbon black.

Our hypothesis is that these materials may be physically obstructing their ability to perform basic biological functions. It could be blocking their digestion, or might be interfering with their ability to breathe.

Peter Piermarini, Study Co-Author and Associate Professor, Entomology, The Ohio State University

Piermarini, on the other hand, found one thing particularly surprising.

Carbon black appeared to be equally toxic to larvae of insecticide-susceptible and insecticide-resistant mosquitoes when suspended in water at first, but the longer it was suspended in water before being treated, the more toxic it became. For insecticide-resistant larvae, it became more toxic.

When you first apply the CNP solution it has similar toxicity against both strainsBut when you let the suspension age for a few weeks, it tends to become more potent against the resistant strain of mosquitoes.

Peter Piermarini, Study Co-Author and Associate Professor, Entomology, The Ohio State University

Although the researchers were unable to pinpoint the cause of the time-lapsed deaths, they concluded that using these new nanomaterials as a preventive treatment on mosquito breeding grounds could be extremely effective in controlling the species.

Carbon black, however, must undergo extensive testing before it can be used by the general public, according to Piermarini, to ensure that it will not harm humans or the environment as a whole.

Erick Martinez Rodriguez, a visiting scholar in the Ohio State Entomology Graduate program, Parker Evans, a former Ph.D. student in the Ohio State Translational Plant Sciences Graduate Program, and Megha Kalsi, a former postdoctoral researcher in entomology, were co-authors of the paper. Ohio State’s College of Food, Agricultural, and Environmental Sciences, as well as Vaylenx LLC, funded this research.

Disease Spreading Mosquito

Disease Spreading Mosquito. Video Credit: The Ohio State University.

Journal Reference:

Rodríguez, E. J. M., et al. (2022) Larvicidal Activity of Carbon Black against the Yellow Fever Mosquito Aedes aegyptiInsectsdoi.org/10.3390/insects13030307.

Source: https://www.osu.edu/

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Friday, 15 April 2022 07:46:48

Grahame Jackson posted a new submission ‘Researchers investigate garlic’s hidden powers’


Researchers investigate garlic’s hidden powers

University of Queensland

Garlic has traditionally been used to ward off evil spirits, but its reputed powers do not stop it from being infected by multiple viruses.

University of Queensland plant virologist Associate Professor John Thomas said garlic was unique, as it was difficult to get virus-free garlic anywhere in the world.

“There can be up to 10 or 12 viruses in infected plants and most garlic plants would have at least six viruses,” Dr Thomas said.

“All Australian commercial garlic varieties have viruses, which doesn’t seem to affect taste or nutrition, but does have an impact on the crop’s yield.”

Understanding that suite of viruses and their impact is the problem Dr Thomas, UQ colleagues Dr Stephen Harper and Associate Professor Andrew Geering, the Department of Agriculture and Fisheries’ Dr Kathy Crew and PhD candidate Sari Nurulita, are investigating.

Ms Nurulita’s doctoral study aims to develop reliable virus detection tests and investigate why both superior and inferior garlic plants share the same viral profile.

“Garlic is a vegetatively propagated crop, and once it’s been infected, all the progeny are infected,” Dr Thomas said.

“It’s also possible for the crop to collect more viruses in the field, but not lose any plants.”

He said in previous work led by Dr Harper and funded by the Australian Centre for International Agricultural Research, researchers grew higher performing bulbs among virus-infected garlic crops.

“Through breeding selections over generations, Dr Harper was getting three times the yield from the best selections,” Dr Thomas said.

“However, Ms Nurulita’s work shows these elite garlic selections are still infected by the virus complement and we don’t know why that is occurring.”

Ms Nurulita also investigated the viruses concentrations using next-generation sequencing, and mapped the full genomes of the viruses.

“I did not find any significant differences in the viruses levels and was unable to determine a clear-cut difference between the two different lines of elite and poor performing garlic seed,” Ms Nurulita said.

Dr Thomas said the team had also tried tissue culture propagation to generate virus-free garlic, but without success.

“We think maybe gene silencing is happening naturally in the plant,” he said.

“It may depend on which virus gets the upper hand in a particular clove, or the order they are infected in.

“There are so many different possibilities and it’s not a simple matter.

“But we are going to look at absolute levels of virus to see whether we can determine if gene silencing is responsible.”

Photos are available via DropBox.

Image above left: Sari Nurulita with high and low yielding garlic, which share the same viruses. (C) UQ.

Media: Associate Professor John Thomas, j.thomas2@uq.edu.au, + 61 (0)400 579 449; Margaret Puls, + 61 (0)419 578 356.

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BCPC’s GM/Biotech Crops Report – April 2022

5th April 2022

  • GM/Biotech Crops Monthly Reports (BELOW) form part of BCPC’s free three-tier Biotech Crops Info service.
  • This service also includes a weekly round-up of news from around the globe – see BCPC Newslink GM Crops section.
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GM/Biotech Crops Monthly Report April 2022

Lettuce in space

Astronauts that spend a long time in space can suffer from a loss of bone density due to the reduced gravity but now a team at the University of California have developed a genetically-modified lettuce that produces a drug that can offset this loss and that can be grown in space to provide the astronauts with fresh green leaves to eat. Pic: Mel Edwards. Full Story.

Antibiotics on crops

While Europe bans neonicotinoids to ensure no harmful effects to bees, America is spraying apple and pear orchards with streptomycin to control the bacterial disease fire blight. A study has shown that bees exposed to the streptomycin are less active and collect less pollen than those that are not exposed to the antibiotic.
Full Story.

An elixir of youth

Some people try blood transfusions from young people to recapture that youthful zest for life and now a study has produced some evidence supporting that hope. Young mice blood contains packets of chemicals (extracellular vesicles) budded off from dividing cells that, when injected in to old mice, restores grip strength, stamina and motor coordination. Sadly the effect wears off after a couple of months but another injection can restore it.
Full story

BT maize resistant to stem borer attack

An evaluation of BT maize in Uganda has confirmed a reduction of leaf damage and stem attack that has led to yield increases of 30 – 80%.
Full Story.

Salt-tolerant cotton

A relative of Arabidopsis has yielded a trait that can be used to confer salt tolerance to cotton which could allow the crop to be grown on more land but could also boost yields in areas where it is already grown.
Full Story

Herbicide-tolerant tomatoes

Scientists in Korea have used gene editing to alter three enzymes in tomatoes. The benefits of changes to PDS and EPSPS enzymes are unclear but the changes to the ALS enzyme can confer tolerance of ALS herbicides similar to the naturally-occurring tolerance recently introduced in sugar beet.
Full Story

Potato genome decoded

Scientists at the Max Planck Institute and the Ludwig Maximillian University have decoded the entire genome of potatoes and this knowledge is to be used to develop improved varieties for future cropping. The following link takes you to the German text which can be translated by computer.
Full Story

Gene expression imbalance boosts wheat yields

Researchers at Kansas University have found that varying the expression of various genes in wheat can affect the grain size and final yields. This knowledge can possibly be used to optimise yields of new varieties.
Full Story

Control of Fall Army Worm

Pilot studies in Brazil have shown that release of Oxitec’s ‘Friendly’ male army worms can reduce the populations of army worms due to the males carrying a male only trait and that this reduction will help to protect the Bt maize that is grown there from resistance developing in the wild population. It is very target specific and has no effect on other species such as bees.
Full Story

USDA approved gene-edited cattle

The USDA has decided that gene-edited beef cattle that have shorter hair than unedited cattle pose no safety concerns and can be marketed without waiting for a specific approval:
Full Story

Europe approves transgenic maize with stacked traits

The EFSA finds no safety concerns in GM maize with stacked traits for insect resistance and tolerance of glyphosate and glufosinate. This permits the import of these crops but it still does not allow them to be grown in Europe.
Full Story

Stripe rust resistance in wheat

An international team has identified the specific gene that confers resistance to stripe rust in the African bread wheat variety ‘Kariega’ and now this trait can be transferred to other varieties.
Full Story

Gene-silencing for weed control

Colorado University has developed a spray that contains antisense oligonucleotides that penetrate the leaves of the weed Palmer amaranth and silence essential genes in the weed. Palmer amaranth has developed resistance to a number of herbicides but this spray is specific to this weed and has no effect on the crop or non-target organisms.
Full Story

Nutritional Impact of regenerative farming

The University of Washington has compared crops grown on land under regenerative farming management with crops grown on adjacent conventionally farmed land and has shown that the regenerative farming crops have higher levels of vitamins, minerals and other phytochemicals. They don’t give any comparison of the yields achieved though and perhaps the higher levels of vitamins etc are simply due to them being distributed through lower yielding crops.
Full Story

Transgenic sugarcane

Sugarcane with overexpressed sucrose-phosphate synthase has been trialled in Indonesia has shown increased tiller number, height and yield than conventional varieties without affecting bacterial diversity or gene horizontal flow in the soil.
Full Story

Potato virus Y resistance

Researchers in Iran have used gene-silencing techniques to develop potatoes that exhibit resistance to potato Y virus.
Full Story

GM barley trials in the UK

Fertiliser prices have gone through the roof and NIAB in conjunction with Cambridge University at the Crop Science Centre are to trial gene modified and gene edited lines of barley to see if they can improve the nitrogen and phosphorus uptake of the plants and make them less reliant on applied fertilisers. If successful on barley, it could be rolled out to other crops.
Full Story

Palm oil replacement

Palm oil is widely used in many products but the proliferation of palm plantations is responsible for a lot of habitat loss throughout the world. Now a team at Nanyang technological University in Singapore have developed a technique for producing the oil from common microalgae.
Full Story

Corn borer resistant maize

Zhejiang University in China has developed a genetically modified maize that has insect resistant traits and a 5 year study has shown it can give up to 96% reduction in corn borer damage and a 6 – 10% yield increase over conventional varieties.
Full Story


The latest approvals of biotech crops to report this month:

• GMB151 – soybean tolerant of isoxaflutole herbicide approved for food use in Canada and for environmental use in America


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Tiny wasps could help save trees under attack

Emerald ash borers have killed millions of trees in North America. Another insect might solve the problem.

Tiny wasps could help control emerald ash borers – The Washington Post

By Gina Rich

March 23, 2022 at 7:30 a.m. EDT

Listen to article

3 min

An adult emerald ash borer feeds on an ash leaf. The beetles eat only ash trees, and they have killed millions of them in North America. Scientists have found wasps that feed on the beetles’ young, keeping the ash borers from killing all the ash trees in Asia and Russia. They are experimenting on releasing those wasps in parts of the United States. (Jian Duan/USDA ARS)

Up close, the emerald ash borer is a strikingly beautiful insect. It’s also a dangerous pest.

The metallic green beetles entered the United States from northeast Asia in the 1990s, likely hitching a ride on wood-packing materials. By the time researchers identified them in 2002, the insects were widespread. They’ve destroyed millions of ash trees across North America.

Ash borers damage trees by “essentially both dehydrating and starving the tree,” says Elizabeth Barnes, anexotic-forest pest educatorin the Purdue University Department of Entomology. Adult ash borers lay eggs on ash trees. The larvae then tunnel under the bark to feed on the tissue that transports the trees’ nutrients. (Larvae are the juvenile form of an insect.)

You’ll see zigzag patterns in the bark of affected trees, Barnes says. When the trees fall, “it looks like they’re exploding. They just absolutely shatter.”

Natural enemies

But there’s good news. As researchers studied the emerald ash borer, they noticed something interesting: Both China and the Russian Far East had abundant ash trees and ash borers, yet fewer trees were dying there.

An adult wasp drills through ash bark to lay eggs inside the emerald ash borer larvae feeding beneath the bark. Wasps use their antennae to figure out where to drill. (Jian Duan/USDA ARS)

Researchers think there are two reasons. First, because trees in those regions evolved alongside the insects, the trees probably developed defenses against them, says Jian Duan. Duan is a research entomologist with the Beneficial Insects Introduction Research Unit at the United States Department of Agriculture.

Second, with insect pests such as ash borers, “there are a lot of natural enemies,” Duan says. Researchers suspected the beetles had a predator that was keeping them in check. If that was true, a biocontrol program — bringing the predator to the pest — could help trees in the United States.

“The purpose of biocontrol is not to eradicate the emerald ash borer,” Duan says. Instead the goal is to keep the pests’ populations low enough for trees to survive.

Stingless wasps

Scientists discovered the ash borers’ natural enemies are small parasitoid wasps, native to China and the Russian Far East. Parasitoids (para-sih-toyds) lay their eggs inside or on the host — in this case, ash borer eggs or larvae. The wasp babies feed on and ultimately kill the host.

The wasps were taken to a quarantine facility, where they were tested to ensure that they would attack only ash borers, not other species. Then researchers worked in the lab to produce thousands of wasps, plus their food source — emerald ash borers. Finally, to make sure the wasps connected with their target, scientists carefully synchronized their release into nature with the ash borers’ activity.

This emerald ash borer larva was eaten by wasp larvae. The wasps don’t kill all the emerald ash borers, just enough to save some of the ash trees. (Jian Duan/USDA ARS)

Because the wasps are only interested in emerald ash borers, “they don’t sting,” Duan says. “Their purpose is to reproduce.” When an adult wasp locates ash borer eggs or larvae, it uses a tubelike organ called an ovipositor to deposit its babies.

U.S. regulators have approved four wasp species for biocontrol: three from China and one from Russia. At test sites in Michigan and New England, the wasps are starting to make an impact, reducing ash borer populations.

Though the pests greatly outnumber the wasps for now, Duan is optimistic. “We still think the natural enemy eventually will catch up with emerald ash borer populations.”

Learn more

You can see a video about ash borer biocontrol by the Virginia Department of Forestry at wapo.st/ash_borers.

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Biocontrol agent released to fight invasive weed in Australian national park

Source: Xinhua| 2022-03-24 12:47:00|Editor: huaxia


CANBERRA, March 24 (Xinhua) — Australia’s national science agency has deployed a biocontrol solution to an invasive weed that poses a major threat to shorebirds including penguins.

A team from the Commonwealth Scientific and Industrial Research Organization (CSIRO) on Thursday released the fungus Venturia paralias into Victoria’s Port Campbell National Park to prevent the spread of the invasive coastal weed sea spurge.

The sea spurge, also known as Euphorbia paralias, is a flowering plant native to Europe, northern Africa and western Asia. It can alter the structure of sand dunes and displace vegetation, disrupting the nesting patterns of shorebirds.

“The weed also has a sap which can cause irritation to animals as well as humans,” CSIRO scientist Gavin Hunter said in a media release.

“Sea spurge grows along Australia’s southern coastline and is a concern for coastal ecosystems. We’re hopeful the biocontrol agent will help reduce the dense weed from penguin nesting sites at Port Campbell, and many other beaches along the coastline where the weed occurs.

“There are many challenges with current methods for removing sea spurge so finding a biocontrol agent for the weed was important to complement existing management strategies of hand pulling and chemical sprays that are very labour intensive, costly, and can not easily be deployed in difficult-to-access beaches,” the release said.

Discovered on the Atlantic and Mediterranean coasts of France, Venturia paralias causes lesions on the stems and leaves of sea spurge plants.

Following extensive tests at the CSIRO’s quarantine facility in Canberra researchers decided it was safe to release into the national park, which is a popular tourist destination due to its penguin population.

“Our research found that the fungus is highly specific toward sea spurge. Based on our results, the fungus was approved by the regulator for release in Australia,” research technician Caroline Delaisse said. ■

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