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Robotic weed removal eliminates need for expensive hand crews

TAGS: TECHNOLOGYTodd FitchetteFarmWise weederSingle-

Single-line organic cauliflower is weeded with a robot developed and operated by the Salinas-based FarmWise.FarmWise offers a business model that provides weeding services, freeing the grower from having to own and maintain a machine.

Todd Fitchette | Dec 04, 2020

Produce growers in Arizona and California are being introduced to the futuristic world of George Jetson as robots and artificial intelligence replace labor crews used to rogue weeds from lettuce, cauliflower, and other vegetable crops.

Salinas, Calif.-based FarmWise is a service company with a robotic weeding machine capable of rouging weeds at speeds of one-to-two miles per hour. This eliminates the need for expensive hand crews or chemical herbicides.

The FarmWise weeding machine is part of a service FarmWise provides. Unlike some companies that sell the machines, FarmWise offers a business model that provides weeding services, freeing the grower from having to own and maintain a machine.

The Titan FT35 is the third generation of machines developed by FarmWise. Company Chief Executive Officer Sebastien Boyer said testing on previous generations of machine took place over the past several years. The newest generation of machine is being used commercially in California and Arizona. https://c8c1c3523498a4e6800111cf107f6155.safeframe.googlesyndication.com/safeframe/1-0-37/html/container.html

The machine uses artificial intelligence to learn the various crops by studying the plant structure, according to Sal Espinoza, regional manager with FarmWise. Once the computer successfully learns the stem structure of the produce plant, the ability to cull weeds is simple. This process can take a few months of machine learning to get it right, Boyer said.

The machines can be outfitted with as many as six weeders. These are the rows of internal components that contain the metal knives that cut through the soil and rogue weeds as cameras track the vegetation and the AI of the onboard computer determines whether the plants are the planted produce, or weeds.

Boyer said his long-term goal is to find additional ways to mechanize the manual labor and tedious tasks performed by human hands. Through the machine learning the AI can distinguish cauliflower, celery, broccoli, and cabbage. Other crops including tomatoes and pepper are being perfected.

The company’s current business model is focused on providing services to produce growers in the desert region of southern California and Arizona after an inaugural run in the Salinas Valley. Boyer said he is also looking at European markets to expand his machine weeding technology.

Aphelenchoides besseyi

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EPPO Datasheet: Aphelenchoides besseyi

Last updated: 2020-07-24

IDENTITY

Preferred name:Aphelenchoides besseyi
Authority: Christie
Taxonomic position: Animalia: Nematoda: Chromadorea: Rhabditida: Aphelenchoididae
Other scientific names: Aphelenchoides oryzae Yokoo, Asteroaphelenchoides besseyi (Christie) Drozdovski
Common names in English: rice leaf nematode, rice white-tip nematode, strawberry crimp disease nematode, white-tip nematode
view more common names online…
Notes on taxonomy and nomenclature

The taxonomy used in this datasheet reflects developments suggested by several recent publications, summarised in Decraemer & Hunt (2013), which place Aphelenchoides in the Order Rhabditida, Suborder Tylenchina. This contrasts with the taxonomy nomenclature occasionally used by some authors (such as the CABI Invasive Species Compendium CABI, 2019; Wheeler & Crow, 2020), which place Aphelenchoides in the Order Aphelenchida, Suborder Aphelenchina (Hunt, 1993). Whilst this makes no difference to classification from the level of Superfamily (Aphelenchoidea) to species level (Aphelenchoides besseyi), those studying the species might need to be aware of differences in the literature.EPPO Categorization: A2 list
EU Categorization: RNQP (Annex IV)
view more categorizations online…
EPPO Code: APLOBE HOSTS 2020-07-24 GEOGRAPHICAL DISTRIBUTION 2020-07-24 BIOLOGY 2020-07-24 DETECTION AND IDENTIFICATION 2020-07-24 PATHWAYS FOR MOVEMENT 2020-07-24 PEST SIGNIFICANCE 2020-07-24 PHYTOSANITARY MEASURES 2020-07-24 REFERENCES 2020-07-24 ACKNOWLEDGEMENTS 2020-07-24 How to cite this datasheet? Datasheet history 2020-07-24

August 4, 2021

Laura Hollis

PlantwisePlus: Helping farmers grow safer, higher quality food

Dr Monica Kansiime is one of the Global Team Leaders for CABI’s new global PlantwisePlus Programme. Building on the success over the last ten years of CABI Plantwise, the new programme aims to enable smallholder farmers to increase incomes and grow safer, higher quality food through climate-resilient approaches to crop production. 

safer food, PlantwisePlus
© CABI

Identifying the challenges

Dr Kansiime’s role within the programme is to identify key safety challenges related to food production. In addition, activities to increase demand for and supply of safer and higher quality farm produce will also be implemented. At least 80% of food consumed in developing regions is grown by smallholder farmers. Raising awareness of agricultural best practice and nutritional information, including safer pesticide use, will help farmers to produce safer, more nutritious food. Not only will this open up new markets to farmers, but local communities will gain access to higher quality, healthier produce. 

Farmer in Uganda
© CABI

Since joining CABI in 2015 Dr Kansiime has gained extensive experience in the agriculture sector programming, providing strategic leadership, research and development at regional and global levels. She has designed and coordinated objective and high-quality research on identified economic and social issues pertinent to CABI projects/programmes and with regional significance, to facilitate learning, program adaptation and evidence-based programming.  

Three key issues

Within this workstream three main issues are being addressed in the initial 3 years of the programme: 

1. Increasing local demand for safer produce within selected agricultural value chains, 

2. Encouraging farmers to work to a voluntary crop production standard to deliver safer, environmentally friendly produce,  

3. Increasing job opportunities for young men and women in rural communities to provide agricultural services to local producers. 

fall armyworm on a leaf
© CABI

Pesticide use

One of the first steps has been to examine the use of pesticides in rural communities. The increase in devastating crop pests, such as the fall armyworm and tomato pinworm, has led to a growth in pesticide use among smallholder farmers, with a prevalent tendency not to adhere to safety precautions.

Frequent use of synthetic pesticides, combined with limited adherence to safety precautions, can have serious implications on the environment, human and animal health.. Because of the hazards associated with pesticides and the risks that they pose, pesticide life cycles are governed by national, regional and international agreements and regulations.

Literature review

An initial literature review has been conducted by Melanie Bateman, one of the team members, to determine whether there is any evidence of pesticide residues exceeding minimum residue limits (MRLs), particularly in domestic markets, and, if so, which pesticides and on which crops.

woman in a market
© CABI

Food safety

Concurrently, a situational assessment is being done focusing on Africa and Asia to understand: the context of food safety within the respective countries; factors that contribute to causing the problem; key stakeholders and what is being done already; and gaps. At the same time, a consumer survey will be carried out to understand consumers’ knowledge, judgments, and practices related to food safety, in particular pesticide safety.

Stakeholder engagement

The combined evidence will be used to engage key stakeholders on the subject of pesticide residue levels to encourage both internal and public dialog on the matter. Similarly, engagements with policy makers and farmers will be done to accelerate adoption of practices that support production of higher quality and safer food by reducing the negative effects of pesticide misuse. The information will also support effective risk communication strategies targeting consumers.

About PlantwisePlus

PlantwisePlus is a global programme, led by CABI, to increase incomes and grow safer and higher quality food through sustainable approaches to crop production.

Working in close partnership with relevant actors, PlantwisePlus strengthens national plant health systems from within, enabling countries to provide farmers with the knowledge they need to lose less and feed more.

CABI gratefully acknowledges the financial support of the Directorate General for International Cooperation (DGIS, Netherlands), the European Commission Directorate General for International Partnerships (INTPA,EU), the UK Foreign, Commonwealth & Development Office (FCDO), the Swiss Agency for Development and Cooperation (SDC), for the PlantwisePlus programme.

For more information visit: https://www.plantwise.org
Facebook: https://www.facebook.com/Plantwise
Twitter: https://twitter.com/CABI_Plantwise (@CABI_Plantwise)

Preview(opens in a new tab)Add titleGene editing poised to spark innovation in herbicide- and disease-resistant sugar cane

Gene editing poised to spark innovation in herbicide- and disease-resistant sugar cane

Julie Wurth | CABBI | July 22, 2021

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Credit: Fawakih
Credit: Fawakih

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

Sugarcane is one of the most productive plants on Earth, providing 80 percent of the sugar and 30 percent of the bioethanol produced worldwide. Its size and efficient use of water and light give it tremendous potential for the production of renewable value-added bioproducts and biofuels.

But the highly complex sugarcane genome poses challenges for conventional breeding, requiring more than a decade of trials for the development of an improved cultivar.

Two recently published innovations by University of Florida researchers at the Department of Energy’s Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) demonstrated the first successful precision breeding of sugarcane by using CRISPR/Cas9 genome editing — a far more targeted and efficient way to develop new varieties.

CRISPR/Cas9 allows scientists to introduce precision changes in almost any gene and, depending on the selected approach, to turn the gene off or replace it with a superior version. The latter is technically more challenging and has rarely been reported for crops so far.Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.SIGN UP

“Now we have very effective tools to modify sugarcane into a crop with higher productivity or improved sustainability,” [researcher Fredy] Altpeter said. “It’s important since sugarcane is the ideal crop to fuel the emerging bioeconomy.”

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A world first: Philippines will soon start eating GMO “golden rice”

The variety of rice can help tackle childhood malnutrition and promises to bring a revolution in the developing world.

Fermin Koop by Fermin KoopAugust 1, 2021 in EnvironmentEnvironmental IssuesHealth & MedicineNutrition

ZME News

Developed by Philippines’ Department of Agriculture in partnership with the International Rice Research Institute, this rice is just what the doctor ordered: it contains additional levels of beta-carotene, which then the body converts into vitamin A. 

“It’s a really significant step for our project because it means that we are past this regulatory phase and golden rice will be declared as safe as ordinary rice,” Russell Reinke of the International Rice Research Institute told AFP. “The next step is to take out few kilos of seeds and multiply it, so it can be made widely available.”

A new type of rice

Image credit: Pixabay

Golden rice has a rich history, with researchers from Germany and Switzerland starting to look into it in 1982. Then, in 1999, various groups came together and continued the research, successfully triggering beta carotene production in rice in 1999. An improved version was later produced with Syngenta, with much higher levels of beta carotene. The body converts beta carotene into vitamin A (retinol).

While ordinary rice does produce beta carotene, it’s not found in the grain. Thus, scientists used genetic engineering to add the compound to the grain. The beta carotene is identical to the one found in green leafy and yellow-colored vegetables, orange-colored fruit, and even in many vitamin supplements and food ingredients.

However, GMOs ares not without their critics. If anything, critics outnumber and outpower the supporters.

This new type of rice was harshly questioned by environmental organizations opposed to genetically altered food plants, such as Greenpeace. While it has now passed the final regulatory hurdle, the rice is still far from appearing across Asia. Limited quantities of seed would start being distributed to selected farmers next year.

“The only change that we’ve made is to produce beta-carotene in the grain,” Reinke told AFP, replying to the criticism. “The farmers will be able to grow them in exactly the same way as ordinary varieties. It doesn’t need additional fertilizer or changes in management and it carries with it the benefit of improved nutrition.”

Why this matters

The vitamin comes directly from animal products and indirectly from beta carotene in plants, which the human body can convert to Vitamin A.  As rice is a staple food in many communities in Asia, golden rice could be of significant help in improving these areas’ vitamin A status once the grain becomes available for public consumption.

Still, there are some unanswered questions. In a recent blog post, US researchers Dominic Glover and Glenn Stone said the claim that golden rice will remedy the Vitamin A deficiency remains unproven. Plus, the families that are poor enough to be affected by VAD in the Philippines often lack land to grow rice for themselves.

“The Philippines has managed to cut its childhood VAD rate in half with conventional nutrition programs. If Golden Rice appears on the market in the Philippines by 2022, it will have taken over 30 years of development to create a product that may not affect vitamin levels in its target population, and that farmers may need to be paid to plant,” they wrote.

This could be a turning point for not just the Philippines, but for the rest of the world as well. Many researchers have supported the implementation of some GMO foods such as golden rice, but due to popular opposition, plans haven’t really caught on.

Philippines Becomes First Country to Approve GMO ‘Golden Rice’

Modern Farmer

JUL 28, 2021Dan Nosowitz

The rice is supposed to help with childhood nutrition. But will it?The golden rice is the yellow one.Photography courtesy of International Rice Research Institute

Genetically modified crops are common in countries such as the United States, but generally they’re modified for two things: efficiency and profit.

Golden rice, which is a short-grain rice genetically modified to contain beta-carotene, was first developed in 1999, in Switzerland. But the rice’s journey to federal approval has been slow and filled with opposition. This week, the government of the Philippines announced that it had approved golden rice, making it the first country to do so.

Golden rice is a variety of rice that has been genetically modified to combat vitamin A deficiency, thanks to the inclusion of beta-carotene. This pigment is red-orange in color and is found in many plants, most famously carrots (hence the name). The human body converts beta-carotene into vitamin A, which is an important nutrient for the immune system, for vision and for digestion. Vitamin A deficiency is a significant problem in some parts of the world, with the World Health Organization estimating deficiency in about a third of all preschool-aged kids.

The Philippines has been leading the charge for golden rice, with much of the development and testing taking place there. But the path for this rice has not been easy, and in some ways it has devolved into the same debate about genetically modified foods seen over the past few decades. 

Proponents say that golden rice is a potentially life-saving creation, that it can deliver around 50 percent of the daily recommended allotment of vitamin A in a single cup of rice. Supporters include the Bill and Melinda Gates Foundation, which has funded research into the GMO grain.

Opponents include organizations such as Greenpeace. Some are opposed to GMO food on principle, no matter what. Many have noted that the development of GMO crops has historically benefited huge corporations such as Monsanto and Syngenta, rather than farmers or consumers, and that the millions of dollars golden rice has required to develop could have been used for more cost-effective nutrition programs. There’s also uncertainty about whether a yellow-colored rice would actually be appealing in regions where rice is typically white.

Currently, the rice has moved “past the regulatory phase,” according to the Philippine Star, meaning it has been declared as safe as any other rice, and is ready to plant.

Kenyan small farmers look to genetically engineered disease resistant cassava to improve food security

Xinhua | July 28, 2021

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Credit: Japhet
Credit: Japhet

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

Catherine Taracha, a scientist at the Kenya Agricultural and Livestock Research Organization (Kalro), is looking forward to starting planting genetically modified (GM) cassava on a trial basis after the government recently approved the process.

“We will do the trials in Western Kenya, at the Coast and in the Eastern part,” Taracha said Monday during a virtual meeting in Nairobi, expressing optimism that in two year’s time, farmers across the country and other parts of East Africa would start growing the crop commercially.Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.SIGN UP

In Kenya, only 970,000 tonnes of cassava are produced annually, and this is because of diseases like cassava mosaic and brown streak as well as pests like whiteflies and mealybugs.

For millions of farmers across East Africa, the cassava mosaic disease was a real problem in the mid-1990s as it spread like bush fire in the region, causing over 80 percent yield losses.

Annual yield losses due to the disease are estimated at 7 billion shillings (about 65 million U.S. dollars) in East and Central Africa, according to Taracha.

“We are banking on the GM crop to boost this crop. There is a huge market for cassava because of its huge potential,” she said.

Read the original postRelated article:  China to restrict reliance on foreign seed companies to foster lagging innovation in genetic engineering and advanced breeding

ABC RURAL

Invasive insect fall armyworm on the march, but scientists fight back with an oozing virus and an egg-attacking wasp

ABC Rural / By Jennifer NicholsPosted Sat 24 Jul 2021 at 4:59pmSaturday 24 Jul 2021 at 4:59pm

A close up of a caterpillar on a plant leaf
The fall armyworm has been detected in parts of every state and territory except SA.(Supplied: DPIRD)

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  • A virus that oozes out through a caterpillar’s skin before exterminating it is being investigated as a way to combat an invasive insect that is devastating some Australian crops.

Key points:

  • Invasive fall armyworm has spread through most of Australia
  • An emergency permit now allows the use of a virus against it
  • Beneficial insects are helping farmers fight fall armyworm

Since fall armyworm was first found in the Torres Strait in January 2020, it has spread to every state and territory except South Australia. 

Their moths can travel up to 400 kilometres a night. 

Researchers are looking at chemical-free options to attack the difficult-to-control bug, including a species-specific virus that oozes out of a caterpillar’s skin before the larva disintegrates.

Dr Melina Miles, who leads the Queensland government’s field crops entomology team in Toowoomba, said so far most farmers were using chemicals to attack the insect.

A lady wearing a hat crouches in a field of corn with chewed leaves.
Melina Miles says fall armyworm has resulted in significant challenges for crop growers.(Supplied: Qld Department of Agriculture and Fisheries)

But she expected that use to drop because winter yields were still good despite damage from the caterpillars.

“Through the work that we’ve been doing at depth, we now know that there are a whole suite of natural enemies, parasitoids and predators, that are attacking fall armyworms,” she said. 

“You can have some confidence that there’s some natural mortality going to occur so it’s not just left to you, as the grower, to control it with insecticides.”

Natural enemies

Non-chemical options, including spraying biopesticide onto the leaves of affected plants, could be used in conjunction with beneficial insects to reduce numbers.

Tiny wasps on the tip of a paint brush.
Tiny adult Trichogramma pretiosum wasps on the tip of a fine paint brush.(Supplied: Melina Miles)

Last year, authorities approved an emergency permit for the use of Fawligen, an organically-certified biopesticide that contains a caterpillar virus that only kills fall armyworm.

“As the larva are eating, they’ll take up these little virus particles and they are only activated in a very alkaline insect gut,” Dr Miles said. 

“It penetrates the gut and starts to replicate and the larva stops feeding. Then the virus eventually starts to ooze out through the skin. Eventually it gets to the point where the larva disintegrates, releasing all these virus particles into the crop.

“We just need to do a little more work to understand how growers might best deploy it.” 

A disgusting looking caterpillar.
Dr Miles says within 4-8 days of fall armyworm being infected with Fawligen, it turns into a sack of virus that eventually explodes.(Supplied: Melina Miles)

Four modern insecticides have had varying success against the pest, but fall armyworm have developed a high resistance to synthetic pyrethroids and moderate resistance to carbamate insecticides.

Third generation dairy farmer Don Davies was looking for a chemical free solution when he ordered tiny Trichogramma wasp eggs.

A farmer wearing a cap, blue shirt and vest stands in thigh deep crops with his dairy cows behind him.
Regenerative dairy farmer Don Davies paid to have Trichogramma egg parasitoid wasps released on his property and was pleased with the results.(Supplied: Don Davies)

He spread them throughout his young corn crop to battle a fall armyworm invasion at east Cooyar, on the Darling Downs.

“They took a few weeks to work, but within a month or so we were getting pretty well on top of them,” Mr Davies said.

Black eggs on a stalk with fuzz on them.
The tiny Trichogramma pretiosum parasitoid wasp targets the eggs of fall armyworm.(Supplied: Melina Miles)

For the past thirty years he has avoided using fertilisers by using multi-species cropping on land his family has farmed for more than 100 years.

Brassicas including turnips, combined with clover and herbs, improve the soil and provide habitat and nectar to beneficial insects.

“We were counting up to 200 beneficials per metre in the corn crop,” he said.

“There was up to seven different lady beetles, and there were all these other natural predators there as well as these Trichogramma wasps that seemed to get right on top of the fall armyworm.”

“Some corn stalks were quite devastated with it, but they recovered quite well.”

The caterpillars favour maize, sweet corn, sorghum, capsicum and C4 pastures, which are more adapted to warm or hot seasonal conditions, when fall armyworm are most active.

Ladybirds on the tassles of a cob of corn.
Beneficial insects including ladybirds helped Don Davies control fall armyworm.(Supplied: Don Davies)

Breeding beneficial bugs

Paul Jones from Bugs for Bugs breeds predatory species of insects and mites for mass release on farms.

Ladybirds, lacewings, pirate bugs, and the tiny parasitoid Trichogramma wasps have proven biological allies against fall armyworm.

A man holds up a sheet of carboard and a small container containing insects.
Paul Jones breeds beneficial insects and sends Trichogramma wasp eggs out in compartments in this sheet of cardboard.(Jennifer Nichols)

“Growers have been using a lot of chemicals to control the pest but because it’s so prolific and aggressive, and the resistance factor is such a big issue, it’s very difficult to control,” Mr Jones said.

“We’re working on a premise of the more diverse and the higher the density of beneficials, the better.”

He said bugs were not cheap.

“They are probably equivalent to the expensive chemicals as there are a lot of labour inputs in producing bugs, but the outcome is far more profitable to the grower if he doesn’t have to spray and he’s coming out with a crop which is not damaged with the pest,” he said.

Badly chewed corn leaves.
Dairy farmer Don Davies found fall armyworm after noticing damage on his maize crop.(Supplied: Don Davies)

Dr Miles said the challenge with insecticides was reaching the fall armyworm on the plants.

“Whereas for parasitoids, and predators, that’s much less of a challenge. They can get down into little nooks and crannies, and under the leaves, and so on, much more easily than a grower could get droplets of insecticide,” she said.Posted 24 Jul 202124 Jul 2021Share

  • Related Stories

Release the wasps: Trialling drones to drop predator insects and reduce chemical use

A large drone hovers over rows of green tomato plants.

After decimating crops across the world, the fall armyworm has moved into new Australian territory

Fall armyworm on corn plants

Biosecurity shock as armyworm spreads rapidly south from Torres Strait

A caterpillar, about two centimetres long, in the palm of a person's hand

A very hungry caterpillar that decimated crops around the world has arrived in Australia

More on:

Biopesticides ‘as good as pesticides’ to protect wheat

© Yorkshire Agricultural Society© Yorkshire Agricultural Society

Biological alternatives to chemical pesticides can be used to help deliver comparable wheat yields, according to new research.

The Farmer Scientist Network, supported by Yorkshire Agricultural Society, has been carrying out comparative trials involving spring and winter wheat varieties – see the video below.

The trials found that wheat can be produced using biocontrol technologies, alone or in combination with conventional crop chemistry, while still obtaining similar yields and grain quality.

See also: Why biopesticides will play a bigger role on arable farms

Farmers are under mounting pressure to produce high-quality food that consumers demand due to a series of chemical bans that have limited their toolkit to combat diseases and pests at a time of increasingly challenging weather patterns.

The use of bioprotectants can reduce the environmental impacts associated with chemicals, say the researchers, who hope the trials involving spring and winter wheat varieties could be developed into a viable, widespread solution for growers in the future.

Farmers and scientists joined forces to carry out the Crop Health North project, which aims to find scientific and technological solutions to agricultural challenges.

EU funding

The study was carried out over three years across field sites at Stockbridge Technology Centre and Newcastle University’s Nafferton and Cockle Park Farms. The trials using bioprotectants have been funded through the EU’s European Innovation Partnership (EIP-Agri).

Explore more Know How

Visit our Know How centre for practical farming advice

Bioprotectant specialist Dr Roma Gwynn, director of Biorationale, worked closely with farmers and agronomists to design the trials, having collectively identified an urgent need to explore new, innovative crop protection products.

Bioprotectants are crop protection products found in nature or derived from it, and so they degrade easily once applied to crops.

During the trials, bioprotectants were applied to spring wheat varieties, Willow and Mulika, and winter wheat varieties, Skyfall, Leeds and Sundance.

Three treatment programmes were used, one using conventional chemical crop protection products, one only using bioprotectants and another involving integrated pest management techniques.

The wheat varieties were chosen due to either their susceptibility to diseases or various resistance ratings.

Next steps

David George, reader in precision agronomy at Newcastle University, said: “The project has quite clearly shown that bioprotectants can perform just as well as synthetic crop protection chemistry, especially in integrated programmes.

“The next steps forward are to take the management regimes that have performed very well in our studies to date, and try and look at how we can optimise their use.”

James Standen, director of farming at Newcastle University, added: “We are losing active chemical ingredients to protect crops from pests due to the ‘precautionary principle’ and some crops have now developed a resistance to some chemical treatments, so identifying new opportunities for farmers to help grow profitable wheat crops is really important.”

The Farmer Scientist Network will share the findings during a free webinar from 2-3pm on Wednesday 28 July. Register free for the Crop Health North webinar.

What are biopesticides?

Biopesticides are mass-produced, biologically based agents used for the control of plant pests. They include:

  • Living organisms (natural enemies) – Invertebrates, nematodes and micro-organisms
  • Naturally occurring substances – Plant abstracts; Semiochemicals (eg insect pheromones)
  • Genes (US) – Plant incorporated products

Source: Justin Greaves, University of Warwick

PestNet

Grahame Jackson Sydney NSW, Australia For your information 45 hours ago   0

BLAST DISEASE, RICE – INDIA: (NAGALAND)

An updated version from ProMED
http://www.promedmail.org

Source: Eastern Mirror Nagaland (EMN) [abridged, edited]
https://easternmirrornagaland.com/blast-disease-of-rice-reported-in-mon/

The Department of Agriculture has informed that blast disease of rice has been reported in Mon district [Nagaland]. Immediately after receiving a report, local agricultural officers carried out an extensive survey and spot verification in infected fields. It was found that the fields were infected with rice blast. The crops were in late tillering to panicle initiation stages.

A total of almost 1000 ha [2471 acres] are infected, constituting about 60% of the total cropping area within the affected sub-division. The incidence is 80-90% and over 1000 smallholders are affected.

Communicated by:
ProMED
<promed@promedmail.org>

[Rice blast is caused by the fungus _Pyricularia oryzae_ (previously _Magnaporthe oryzae_). It is one of the most destructive diseases of the crop worldwide, with potential yield losses of more than 50%. Symptoms include lesions on all parts of the shoot, as well as stem rot and panicle blight. When nodes are infected, all plant parts above the infection die and yield losses are severe. When infection occurs at the seedling or tillering stages, plants are often completely killed; infection late in the growth cycle generally leads to less severe damage. Depending on which plant parts are affected, the disease may manifest itself as leaf, collar, node, or neck blast. More than 50 species of grasses and sedges can be affected by related pathogens, but most strains isolated from rice can only infect a limited number of cultivars.

The fungus also causes wheat blast (for example, see ProMED post 20210324.8267471). Although the pathogens are currently classified as the same species, the wheat blast pathogen is a distinct population (referred to as _P. oryzae_ Triticum population) and does not cause disease in rice.

Symptom severity and spread of the blast fungus are influenced by climatic conditions, including high humidity. The disease is also favoured by high nitrogen levels (for example from fertilisers). The fungus is spread by infected plant debris, mechanical means (including insect activity), water, and wind. Disease management may include fungicides and cultural practices but relies mainly on resistant varieties. Use of certified clean seed is essential, farm-saved seed poses a high risk of carry-over of the fungus to subsequent crops.

The fungus is highly variable; this favours the emergence of new strains with increased virulence, including host resistance breaking strains. Environmental factors may also affect plant resistance. Both resistance and defense-regulator genes have been found to be involved in host resistance against blast (see links below) and could potentially be combined (“pyramided”) to develop rice varieties with broad-spectrum host resistance against blast that cannot be as easily overcome by the fungus as varietal resistance based on single genes.

Maps
India (with states):
https://www.worldometers.info/img/maps/india_physical_map.gif and
http://healthmap.org/promed/p/62429
Nagaland districts:
http://i.pinimg.com/736x/2a/92/00/2a9200aa52c45f91e159c6b789d40721.jpg

Pictures
Rice blast symptoms:
http://www.knowledgebank.irri.org/ricebreedingcourse/blast.jpg (different symptomatic forms),
https://www.dpi.nsw.gov.au/__data/assets/image/0006/798765/RiceBlast5.jpg
Rice fields affected by blast:
http://ucanr.edu/blogs/riceblog/blogfiles/22977_original.jpg,
https://guardian.ng/wp-content/uploads/2019/06/Rice-Blast.jpg, and
https://previews.123rf.com/images/imagethink/imagethink1411/imagethink141100067/33260576-rice-blast-Stock-Photo.jpg

Links
Information on rice blast:
http://www.knowledgebank.irri.org/training/fact-sheets/pest-management/diseases/item/blast-leaf-collar (with pictures),
http://www.oisat.org/pests/diseases/fungal/rice_blast.html,
http://www.plantwise.org/KnowledgeBank/Datasheet.aspx?dsid=46103, and
https://www.dpi.nsw.gov.au/biosecurity/plant/insect-pests-and-plant-diseases/rice-blast
Rice blast disease cycle:
https://ars.els-cdn.com/content/image/3-s2.0-B9780123820341000086-f08-05-9780123820341.jpg and
https://www.researchgate.net/profile/Darren_Soanes/publication/7891924/figure/fig2/AS:271700617068555@1441789883887/Life-history-of-Magnaporthe-griseaa-Asexual-spores-called-conidia-germinate-and-develop.png
Research on rice blast host resistance:
https://www.sciencedirect.com/science/article/pii/S1369526618301808 (review),
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0211061, and
https://www.researchgate.net/publication/330889038_Molecular_and_field_level_screening_for_blast_resistance_gene_donors_among_traditional_rice_varieties_of_Kerala
Impact of rice blast (and other fungal crop diseases):
http://onlinelibrary.wiley.com/doi/10.1111/j.1364-3703.2011.00783.x/full
Information on wheat blast:
http://wheatblast.org/ and
http://wheat.org/wp-content/uploads/sites/4/2016/04/Wheat-Blast-Priority-Brief-web-07Apr2016.pdf
_P. oryzae_ taxonomy and synonyms:
http://www.indexfungorum.org/names/NamesRecord.asp?RecordID=224486 and
http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=224486
– Mod.DHA]
 India Pyricularia_oryzae Bast

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Hybrid corn plants owe some of their vigor to soil microbes. BEN HASTY/MEDIA NEWS GROUP/READING EAGLE VIA GETTY IMAGES

Why does corn grow so well? Scientists think soil microbes play a role

By Erik StokstadJul. 29, 2021 , 4:35 PM

Bountiful harvests of corn and other major crops rely on a mysterious phenomenon known as hybrid vigor. When highly inbred varieties are crossed, their offspring are taller, hardier, and bear more grain. Now, researchers report that this vigor is somehow influenced by microbes in the soil, perhaps via a plant’s immune system.

“This is a really interesting finding,” says Giles Oldroyd, a plant geneticist at the University of Cambridge who was not involved in the research. “I am surprised it has taken until now to be studied.”

Charles Darwin was one of the first researchers to describe hybrid vigor. In the early 20th century, biologists began to apply this effect to agriculture by creating inbred parent lines that yielded hybrid seed. By the 1940s, almost every farmer in the United States was planting hybrid corn, and the harvests multiplied.

Geneticists have proposed several theories about the cause of hybrid vigor, but no definitive explanation has emerged.

Maggie Wagner, a plant geneticist at the University of Kansas, Lawrence, and her colleagues wondered whether microbes might be involved. The tiny organisms can have a large impact on plants. For example, leaves and roots are often colonized by communities of beneficial bacteria and fungi that help protect the plant against disease-causing microbes. Some crops, like soybeans and other legumes, host microbes that feed them nitrogen—an essential plant nutrient, which farmers must otherwise deliver with fertilizer.

Last year, Wagner and colleagues found an interesting clue in a field study. They discovered that the leaves and roots of hybrid corn had microbial communities that differed from those living on inbred varieties of corn.

When winter came and the fields were fallow, Wagner tried to replicate the finding with a laboratory experiment. The researchers planted seeds in bags of a soillike substance that had been sterilized to kill all microbes. Then they added a simple community of soil bacteria—seven strains that are known to colonize corn roots—to some of the bags while leaving others sterile. When the microbes were present, the hybrids grew better than an inbred variety, as expected, with roots weighing 20% more. To their surprise, however, the hybrid and inbred corn plants grew about the same in the sterile soil, they report this month in the Proceedings of the National Academy of Sciences. The weight of their roots and shoots hardly differed.

The finding held up when the scientists repeated the experiment by adding a full set of microbes, taken from soil, to some of the sterilized bags. “The results look convincing,” Oldroyd says.

The takeaway? “Something about being a hybrid makes a plant interact differently with microbes,” Wagner says. Based on some of the results, the team thinks microbes retarded the growth of inbreds, rather than giving the hybrids a special boost.

It could be that the inbreds’ immune systems overreact to benign microbes, compromising their growth. (The experiment did not include any pathogens.) Alternatively, hybrid plants may be better able to defend against weak pathogens in the soil. “We have a lot of work planned to follow up on that idea,” Wagner says.

Oldroyd says the results highlight the need for plant breeders to match the genetics of crops to the microbial communities with which they live. The findings drive home the importance of understanding the role of soil microbes in making agriculture more productive and sustainable, adds Corné Pieterse, a plant biologist at Utrecht University. “This holds great promise.”Posted in: 

doi:10.1126/science.abl6957

Erik Stokstad

Erik is a reporter at Science, covering environmental issues. 

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Genes Shared With Viruses Protect Caterpillars from Parasitic Wasps
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Genes Shared With Viruses Protect Caterpillars from Parasitic Wasps

A newly identified gene family named “parasitoid killing factor” is found in both insect-infecting viruses and their hosts, although researchers can’t yet tell where they originated.

Stephanie Melchor
Jun 30, 2021

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ABOVE: The cotton bollworm (H. armigera) is one of the species discovered to have parasitoid killing factor genes.
© ISTOCK.COM, TOMASZ KLEJDYSZ

tI’s a scene straight out of your worst nightmare: dozens of tiny, milky larvae wriggle out of their still-living caterpillar host, leaving behind the scarred, gaping holes from whence they emerged. The larvae belong to a type of wasp called parasitoids, whose young dine on the flesh of hosts their parents pick out for them.  

But research published Thursday (July 29) in Science suggests that not all caterpillars infected with parasitoid wasps will meet the same grisly end. The study identified a new family of proteins—parasitoid killing factors (PKFs)—that kill parasitoid larvae. PKF genes were found in several large double-stranded DNA viruses that infect lepidopteran insects (moths and butterflies), but also within the genomes of several Lepidoptera species themselves, suggesting that the genes have been swapped between viruses and infected hosts over the course of evolutionary history. 

“I thought it was very well done,” says Stockholm University evolutionary biologist Naomi Keehnen, who was not involved with the study. “It’s very, very nice research.”

Studies of host-pathogen interactions often reveal evidence of evolutionary arms races, as organisms hone their strategies for virulence and defense. Virologist Jean-Michel Drezen of the University of Tours in France says viruses usually only encode genes that are absolutely necessary for viral replication and that are involved in adaptation to the host. In this case, however, the viral PKF genes adapted to the virus’s potential parasitoid competitors. “This is quite new in virology,” he says. Drezen has collaborated with some of the paper’s authors in the past but was not involved in the current study. 

Insect virologist Madoka Nakai of Tokyo University of Agriculture and Technology and her team first identified the PKFs in northern armyworm (Mythimna separata) caterpillars—a lepidopteran species—infected with entomopoxvirus. The researchers saw that when the caterpillars were infected with the virus, they were protected from certain parasitoid species. This wasn’t the first time researchers had noted such a connection; in the 1970s, University of California, Davis, entomologist Harry Kaya noticed that virally-infected caterpillars were protected from parasitoids, but didn’t understand the mechanism of protection. 

To find that mechanism, Nakai’s group, working with researchers led by Salvador Herrero at the University of Valencia and Martin Erlandson of the University of Saskatchewan, exposed parasitoids to plasma from the virus-infected caterpillars that had been stripped of any virus particles. The wasp larvae died. By comparing the plasma proteins present in healthy versus virus-infected M. separata larvaethe researchers identified a 28-kDa protein—a PKF—that was only present in the infected insects. Using Edman sequencing—which identifies the sequence of amino acids in a peptide—they worked backward to match the amino acid sequence of the protein to sequences in the viral genomes. In addition to the PKF in the entomopoxvirus, they also found homologs in the genomes of ascoviruses and baculoviruses, which also infect insects. Some viruses had up to five PKFs in their genomes.

See Parasite’s Genes Persist in Host Genomes

While visiting Herrero’s lab in Spain, Nakai presented her group’s discovery of the viral PKFs. While discussing the data with her over coffee, Herrero says he remembers thinking he should do a quick scan through his moth genomic databases, just to see if there was anything similar to PKF genes directly encoded in the moth genome.

Sure enough, they identified PKF genes in the moths as well, and the phylogenetic analysis suggested that horizontal gene transfer of PKFs between the DNA viruses and the insects happened multiple times throughout the evolutionary history of Lepidoptera. 

Nakai says they don’t know yet whether the genes originally moved from virus to host or vice-versa, but the end result of the gene transfer is clear: “The common enemy is the parasitoid,” she says, “so they eliminate the common enemy.”

Previously, “it was expected that virally-infected larvae weren’t appropriate hosts for the development of parasitoids because of resource competition,” says Drezen, “But we did not expect that there was a specific mechanism to kill parasitoid wasps by the viruses, so I was quite surprised to read this paper.”

“It’s very clear that even though we thought that it was very basic, the immune system of insects is not as basic as we think,” says Keehnen. “And we still don’t really know exactly how it works—so I think finding a whole new gene family that’s involved with [antiparasitoid] responses shows that we really need to study more.” The researchers found that PKFs induce apoptosis in susceptible parasitoids. 

Moving forward, the group plans to look for PKFs in other lepidopterans. They are also using CRISPR-Cas9 to make PKF knockout Lepidopterans in order to more clearly understand the roles of each PKF gene, says Nakai. An additional, more conceptual question raised by their research is why ascoviruses, which carry PKFs, are transmitted to Lepidopteran hosts by the very parasitoid wasps they can kill. “It’s a little bit strange,” says Nakai. “Why would ascovirus kill its vector?” 

Further down the road, there may be agricultural applications for the discovery. According to Herrero, harnessing the power of “natural enemies” like parasitoids to manage agricultural pests has been common practice in both conventional and organic farming. Learning more about the PKFs may explain why some pests are resistant to parasitoid killing, and may help inform the design of better natural enemy solutions in the future. 

University of Georgia entomologist Michael Strand, who was not involved in the study, notes that the PKFs are able to kill their insect target, but not their insect host, and the study shows that the PKFs only target certain subfamilies of parasitoids, suggesting that the genes are extremely specific in what they can target. In the future, he says, people may be able to manipulate PKFs to “make them boutique killers” of certain pests. That kind of specificity could be leveraged to avoid using “broad-spectrum, ‘I kill everything I touch’” pesticide strategies. 

The study shows that “the insects that survived the virus had the opportunity to acquire that gene that gives protection against the parasitoid,” says Herrero—demonstrating that in this instance, at least, “what doesn’t kill you makes you stronger.”

Keywords:

agricultureevolutionevolutiongeneticshorizontal gene transferlepidopteraNewsparasitoidparasitoid wasps