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Archive for the ‘Emerging/invasive pests’ Category

Scientific Modeling Helps Defend Tomatoes Against Flying Foe

January 31, 2017
IPM Innovation Lab Director Muni Muniappan inspects tomatoes damaged by Tuta absoluta in Puranchaur, Nepal. The pest was first reported in the country in spring of 2016, and it is already promising to be a big problem for the upcoming tomato-growing season.

Tomatoes are so abundant that they can be easy to take for granted. But a pest known as the South American tomato leafminer, or Tuta absoluta, has been making this popular ingredient harder to find in countries throughout the world. The tomato leafminer hasn’t arrived in the United States yet, but it has made it as far north as Costa Rica. Now, most scientists agree, it’s no longer a question of if this pest will arrive, but when.

“People want to know when Tuta will be in the United States,” said Muni Muniappan, director of the Feed the Future Innovation Lab for Integrated Pest Management, led by Virginia Tech University. “It could be in 1 year or 10 years, but eventually it will be here.”

Fresh and processed tomatoes generated $2 billion dollars in the United States in 2015 and tomato exports totaled $335 million, making America the seventh largest tomato-producing country in the world. An invasion by the tomato leafminer could put a serious dent in those numbers.

Muniappan and the Integrated Pest Management Innovation Lab have been working to combat the pest since it hitched a ride to Spain in 2006, where it then spread through Europe and the Mediterranean and into Central and South Asia and parts of Africa.

“There is no silver bullet for Tuta absoluta,” Muniappan said. “We cannot stop it, but we can slow it down.”

Under these circumstances, the best way to protect countries that have not been reached by the pest is to delay its arrival and increase awareness about it. Then, if it does arrive, the key is to limit its damage with a quick response.

To keep the pest out of America for as long as possible, the Integrated Pest Management Innovation Lab is helping monitor Tuta absouta and assist states in using pheromone traps for early detection. It is also working with Costa Rica to suppress the pest and prevent its northward spread.

When the pest does inevitably enter the United States, quarantine measures will be necessary. To this end, the Integrated Pest Management Innovation Lab recently gave funding to Virginia Tech’s Biocomplexity Institute to model the spread of Tuta absoluta, using human movement as a variable. Most models use only temperature and weather patterns as predictors of disease and pest spread, but the model developed through this project will also consider popular trade and travel routes.

“Our model will be an extremely useful tool to develop strategies to combat these pests,” said Abhijin Adiga, a research faculty member at the Biocomplexity Institute and project lead. “Further, the methodology will not be limited to studying the tomato leafminer but can be applied to any agricultural invasive species.”

Muniappan and the Integrated Pest Management Innovation Lab are raising awareness in America and around the world about the pest. So far, they’ve held 16 international awareness workshops, reaching scientists from 55 countries. At the International Congress of Entomology in October 2016 in Florida, the Feed the Future Innovation Lab led a symposium, resulting in the group recommending several measures, such as undertaking a concentrated effort to look for natural enemies in Tuta’s area of origin in South America and providing information on appropriate insecticide rotations for pest management in the fields.

“With proactive actions,” Muniappan said, “we hope to significantly reduce the economic loss caused by this pest in the United States and around the world.”

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Spread of damaging wheat rust continues: new races found in Europe, Africa, Central Asia

Mediterranean particularly affected by new rust races

Photo: ©FAO/ Fazil Dusunceli

Wheat experts examine a research plot near Izmir, Turkey, affected by wheat yellow rust.

3 February 2017, Rome −  Wheat rust, a family of fungal diseases that can cause crop losses of up to 100 percent in untreated susceptible wheats, is making further advances in Europe, Africa and Asia, according to two new studies produced by scientists in collaboration with FAO.

The reports, highlighted in the journal Nature following their publication by Aarhus University and the International Maize and Wheat Improvement Center (CIMMYT), show the emergence of new races of both yellow rust and stem rust in various regions of the world in 2016.

At the same time, well-known existing rust races have spread to new countries, the studies confirm, underlining the need for early detection and action to limit major damage to wheat production, particularly in the Mediterranean basin.

Wheat is a source of food and livelihoods for over 1 billion people in developing countries. Northern and Eastern Africa, the Near East, and West, Central and South Asia – which are all vulnerable to rust diseases − alone account for some 37 percent of global wheat production.

“These new, aggressive rust races have emerged at the same time that we’re working with international partners to help countries combat the existing ones, so we have to be swift and thorough in the way we approach this,” said FAO Plant Pathologist Fazil Dusunceli. “It’s more important than ever that specialists from international institutions and wheat producing countries work together to stop these diseases in their tracks −  that involves continuous surveillance, sharing data and building emergency response plans to protect their farmers and those in neighboring countries.”

Wheat rusts spread rapidly over long distances by wind. If not detected and treated on time, they can turn a healthy looking crop, only weeks away from harvest, into a tangle of yellow leaves, black stems and shriveled grains.

Fungicides can help to limit damage, but early detection and rapid action are crucial. So are integrated management strategies in the long run.

wheat_stem-rust_1Stem rust

Mediterranean most affected by new rusts

On the Italian island of Sicily, a new race of the stem rust pathogen −called TTTTF− hit several thousands of hectares of durum wheat in 2016, causing the largest stem rust outbreak that Europe has seen in decades. Experience with similar races suggests that bread wheat varieties may also be susceptible to the new race.

TTTTF is the most recently identified race of stem rust. Without proper control, researchers caution, it could soon spread over long distances along the Mediterranean basin and the Adriatic coast.

Various countries across Africa, Central Asia and Europe, meanwhile, have been battling new strains of yellow rust never before been seen in their fields.

Italy, Morocco and four Scandinavian countries have seen the emergence of an entirely new, yet-to-be-named race of yellow rust. Notably, the new race was most prevalent in Morocco and Sicily, where yellow rust until recently was considered insignificant. Preliminary analysis suggests the new race is related to a family of strains that are aggressive and better adapted to higher temperatures than most others.

Wheat farmers in Ethiopia and Uzbekistan, at the same time, have been fighting outbreaks of yellow rust AF2012, another race which reared its head in both countries in 2016 and struck a major blow to Ethiopian wheat production in particular. AF2012 was previously only found in Afghanistan, before appearing in the Horn of Africa country last year, where it affected tens of thousands of hectares of wheat.

“Preliminary assessments are worrisome, but it is still unclear what the full impact of these new races will be on different wheat varieties in the affected regions,” said Dusunceli. “That’s what research institutions across these regions will need to further investigate in the coming months.”

To offer support, FAO, in collaboration with its partners, is stepping up its efforts in training rust experts from affected countries to boost their ability to detect and manage these emerging wheat rust races.

As new races emerge, old ones continue to spread

The already established Warrior(-) race of yellow rust − which came onto scientists’ radars in Northern Europe and Turkey a few years ago −  continued its aerial march in 2016 and is now widely present in Europe and West Asia.

The Digalu (TIFTTF) race of stem rust continues to devastate wheats in Ethiopia, while the most well-known race of stem rust – the highly potent Ug99 – is now present in 13 countries. Having spread in a northward trend from East Africa to the Middle East, Ug99 has the potential to affect many wheat varieties grown worldwide as it keeps producing new variants. Most recently, it has been detected in Egypt, one of the Middle East’s most important wheat producers.

International collaboration crucial

The findings of the Aarhus study build on training sessions conducted in 2016 in collaboration between the International Center for Agricultural Research in the Dry Areas (ICARDA), Aarhus university, CIMMYT and FAO.

The training, which will be repeated this year, allows rust experts to strengthen their surveillance and management skills, coupled with surveys and collection of rust samples for tests and analysis by Aarhus University. The recently established Regional Cereal Rust Research in Izmir, Turkey, will host the training.

These efforts have been part of FAO`s four-year global wheat rust program, which facilitates regional collaborations and offers support to individual countries eager to boost their surveillance capacity.

It also helps countries act swiftly to control outbreaks before they turn into epidemics and cause major damage to food security. But further research, particularly into breeding resistant varieties, and national response plans need to be backed by adequate resources.

FAO, CIMMYT, ICARDA and Aarhus University are working together as members of the Borlaug Global Rust Initiative (BGRI).

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pigweed-butterfly-ga-field-2016 Brad Haire  Feb 06, 2017
Herbicide-resistant weeds didn’t fall from the sky or rise from fields in a mutant mutiny, but they are here nonetheless. With new herbicide technologies going mainstream this season, growers must continue dogged resistant-weed management programs to preserve viable chemistries for as long as possible.

Herbicide-resistant weeds didn’t fall from the sky or rise from fields in a mutant mutiny, but they are here nonetheless. With new herbicide technologies going mainstream this season, growers must continue dogged resistant-weed management programs to preserve viable chemistries for as long as possible.

“In general, herbicide-resistant weeds become a problem over time when they are selected to survive by the overuse of a single herbicide or single mode of action. In all weed populations, there are very low levels or frequencies of herbicide-resistant plants in comparison to susceptible plants,” said Eric Prostko, University of Georgia Extension weed specialist during an American Society of Agronomy webinar “Growing for Tomorrow: How Weed Resistance Management Can Lead to Sustainability”Feb. 1 sponsored by BASF.

The U.S. leads the world with 156 unique cases of herbicide-resistant weeds. “If you grew up in the U.S. like me, you are likely always proud to see American athletes win Olympic gold medals. The more the better, right? Unfortunately, the U.S. is also the gold medal winner for herbicide resistant weeds,” Prostko said.

Australia currently comes in second place with 84 unique cases of herbicide-resistant weeds, and Canada takes third with 64 cases.

Worldwide there are 478 unique cases of herbicide-resistance weeds. The most frequent modes of action that weeds have developed resistance to are the ALS inhibitors (SUs and IMIs), PS II inhibitors (triazine and ureas)  and the ACCase inhibitors (dim and fop grass herbicides), he said.

The over-use of glyphosate on glyphosate-tolerant crops has led to the rapid development of glyphosate-resistant weeds over the last two decades, he said. Today, there are 36 weed species worldwide with resistance to glyphosate with 16 of those species in the U.S.

PPO-resistance is now a growing concern, too. “The evolution of PPO resistance is scary because many growers have been relying on herbicides with this mode of action to help manage herbicide-resistant pigweed. Currently, three weed species have evolved PPO-resistance in the U.S., including tall waterhemp, Palmer amaranth and giant ragweed. PPO-resistant Palmer amaranth is under investigation in Alabama, Mississippi, North Carolina and South Carolina,” he said.

But resistant weed problems do not necessarily result in yield loss. In Georgia where farmers have dealt with glyphosate-resistant pigweed for more than a decade, cotton and peanut yields have continued to increase. But it has come at great cost.

The cost to fight resistant weeds with herbicides in Georgia cotton, for example, has increased since 2004 from $28 per acre to $68 per acre plus a 10 percent to 20 percent increase in cost of mechanical cultivation and an increase in the need for hand weeding going from just under $3 per acre to almost $24 per acre today.

So what can growers do or do better, especially in handling herbicide-resistant Palmer amaranth?

1 – Start weed-free at planting using a combination of tillage, cover crops and herbicides. Although the benefits of reduced tillage systems are many, they have also helped contribute to some of our resistant weed problems. “The deeper and longer Palmer amaranth seeds are buried, the less seed germination will occur. Burying pigweed seed with a moldboard plow every three years or so can be beneficial, particularly in problematic fields. In some cases, deep tillage may not be a practical option,” he said.

2 – For growers who cannot or will not use deep tillage, well-managed cereal cover crops can be used to help reduced the emergence of some weeds. Since Palmer amaranth seed requires light for germination, a heavy rye biomass, for example, can prevent light from reaching the soil surface which ultimately influences germination and emergence. Getting an adequate crop stand in extreme cover crops can often be challenging and requires diligence and practice.

3 – Another tactic that exploit’s the influence of light on weed seed germination and emergence is narrow-row planting. Studies in many crops show narrower rows typically result in better overall weed control.

4 – Use herbicides with multiple effective modes of action. Most, if not all, herbicide labels today have their modes of action listed in plain view. “You no longer have to be a weed scientist to identify different modes of action,” he said.

5 – A strict crop rotation “can be extremely beneficial for the management of herbicide-resistant weeds because multiple herbicide modes of action can be used over time. In the case of a typical cotton-and-peanut rotation in the Southeast, eight different herbicide modes of action can be used over a two year period,” he said.

6 – Don’t cut rates to save money or for any other reason. “The use of reduced herbicide rates has been proven to be one of the factors that can increase the rate of herbicide resistance development. … The bottom line: only full-labeled rates should be used for weed control.”

7 – Reduce the seed bank in field. Many growers know it but it’s worth saying again: pigweed is a ‘seedy’ plant, producing 500,000 to 1 million seeds per plant.

Cotton and soybean seed traits tolerant to new formulations of dicamba and 2,4-D, which are on track to be widely available and legal to spray over the top of crops this season, are expected to be planted in some regions. Both herbicides are in the same auxin herbicide family. “First and foremost, these new auxin technologies are not a miracle cure for all your current weed problems. You will still need to start clean, use residuals and make timely postemergence applications,” he said.

“Although much is being said about the new auxin technologies these days, I am not hearing very much about the fact that auxin resistance in weeds has already occurred,” Prostko said. “These herbicides are not new. Currently, eight weed species in the U.S have already developed auxin-resistance. Auxin technology stewardship will be even more important as we head into the future.”

Chad Asmus, technical marketing manager for BASF, spoke during the webinar and echoed Prostko’s concerns and recommendations for growers to reduce the risk of herbicide resistance developing in their fields, highlighting the company’s newly formulated dicamba herbicide Engenia, which can be sprayed over the top of dicamba-tolerant cotton and soybean.

The new herbicide has a BASF patented molecule called BAPMA, which, Asmus said, is the lowest volatility salt of dicamba with the highest loading and lowest use rate at 12.8 fluid ounces per acre; and it’s rain fast in 4 hours.

The Engenia label comes with many requirements, including buffer areas. Asmus stressed that growers must follow the label requirements thoroughly. Here are a few of the general federal requirements for Engenia:

  • Use the TTI11004 spray nozzle.
  • Boom Height: ≤ 24” above the target.
  • Application Volume: ≥ 10 GPA.
  • Ground Speed: ≤ 15 MPH.
  • Wind Speed and Direction: 0 to 15 MPH
    • For wind speeds ≤ 3 MPH confirm there is no field level temperature inversion.
    • Do not spray with wind speeds >10 MPH blowing toward neighboring sensitive non-specialty crops.
    • Do not spray with any wind blowing towards neighboring specialty crops.

Asmus said growers need to also pay special heed to any state-specific label requirements that might apply to Engenia this year. An updated list of EPA-approved tank-mix products for Engenia can be found at http://www.EngeniaTankMix.com.

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IBIS daily digest

Morning Agclips

WHEAT DISEASE …

Found in Europe, Africa, Central Asia; Mediterranean particularly impacted

Wheat experts examine a research plot near Izmir, Turkey, affected by wheat yellow rust. (Courtesy Photo)

 

ROME — Wheat rust, a family of fungal diseases that can cause crop losses of up to 100 percent in untreated susceptible wheats, is making further advances in Europe, Africa and Asia, according to two new studies produced by scientists in collaboration with FAO.

The reports, highlighted in the journal Nature following their publication by Aarhus University and the International Maize and Wheat Improvement Center (CIMMYT), show the emergence of new races of both yellow rust and stem rust in various regions of the world in 2016.

At the same time, well-known existing rust races have spread to new countries, the studies confirm, underlining the need for early detection and action to limit major damage to wheat production, particularly in the Mediterranean basin.

Wheat is a source of food and livelihoods for over 1 billion people in developing countries. Northern and Eastern Africa, the Near East, and West, Central and South Asia – which are all vulnerable to rust diseases − alone account for some 37 percent of global wheat production.

“These new, aggressive rust races have emerged at the same time that we’re working with international partners to help countries combat the existing ones, so we have to be swift and thorough in the way we approach this,” said FAO Plant Pathologist Fazil Dusunceli. “It’s more important than ever that specialists from international institutions and wheat producing countries work together to stop these diseases in their tracks −  that involves continuous surveillance, sharing data and building emergency response plans to protect their farmers and those in neighboring countries.”

Wheat rusts spread rapidly over long distances by wind. If not detected and treated on time, they can turn a healthy looking crop, only weeks away from harvest, into a tangle of yellow leaves, black stems and shriveled grains.

Fungicides can help to limit damage, but early detection and rapid action are crucial. So are integrated management strategies in the long run.

Mediterranean most affected by new rusts

On the Italian island of Sicily, a new race of the stem rust pathogen −called TTTTF− hit several thousands of hectares of durum wheat in 2016, causing the largest stem rust outbreak that Europe has seen in decades. Experience with similar races suggests that bread wheat varieties may also be susceptible to the new race.

TTTTF is the most recently identified race of stem rust. Without proper control, researchers caution, it could soon spread over long distances along the Mediterranean basin and the Adriatic coast.

Various countries across Africa, Central Asia and Europe, meanwhile, have been battling new strains of yellow rust never before been seen in their fields.

Italy, Morocco and four Scandinavian countries have seen the emergence of an entirely new, yet-to-be-named race of yellow rust. Notably, the new race was most prevalent in Morocco and Sicily, where yellow rust until recently was considered insignificant. Preliminary analysis suggests the new race is related to a family of strains that are aggressive and better adapted to higher temperatures than most others.

Wheat farmers in Ethiopia and Uzbekistan, at the same time, have been fighting outbreaks of yellow rust AF2012, another race which reared its head in both countries in 2016 and struck a major blow to Ethiopian wheat production in particular. AF2012 was previously only found in Afghanistan, before appearing in the Horn of Africa country last year, where it affected tens of thousands of hectares of wheat.

“Preliminary assessments are worrisome, but it is still unclear what the full impact of these new races will be on different wheat varieties in the affected regions,” said Dusunceli. “That’s what research institutions across these regions will need to further investigate in the coming months.”

To offer support, FAO, in collaboration with its partners, is stepping up its efforts in training rust experts from affected countries to boost their ability to detect and manage these emerging wheat rust races.

As new races emerge, old ones continue to spread

The already established Warrior(-) race of yellow rust − which came onto scientists’ radars in Northern Europe and Turkey a few years ago −  continued its aerial march in 2016 and is now widely present in Europe and West Asia.

The Digalu (TIFTTF) race of stem rust continues to devastate wheats in Ethiopia, while the most well-known race of stem rust – the highly potent Ug99 – is now present in 13 countries. Having spread in a northward trend from East Africa to the Middle East, Ug99 has the potential to affect many wheat varieties grown worldwide as it keeps producing new variants. Most recently, it has been detected in Egypt, one of the Middle East’s most important wheat producers.

International collaboration crucial

The findings of the Aarhus study build on training sessions conducted in 2016 in collaboration between the International Center for Agricultural Research in the Dry Areas (ICARDA), Aarhus university, CIMMYT and FAO.

The training, which will be repeated this year, allows rust experts to strengthen their surveillance and management skills, coupled with surveys and collection of rust samples for tests and analysis by Aarhus University. The recently established Regional Cereal Rust Research in Izmir, Turkey, will host the training.

These efforts have been part of FAO`s four-year global wheat rust program, which facilitates regional collaborations and offers support to individual countries eager to boost their surveillance capacity.

It also helps countries act swiftly to control outbreaks before they turn into epidemics and cause major damage to food security. But further research, particularly into breeding resistant varieties, and national response plans need to be backed by adequate resources.

FAO, CIMMYT, ICARDA and Aarhus University are working together as members of the Borlaug Global Rust Initiative (BGRI).

–FAO

– See more at: https://www.morningagclips.com/spread-of-damaging-wheat-rust-continues/#sthash.xFba0wMD.dpuf

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MercoPress

Crop destroying caterpillar rapidly spreading across Africa; maize production endangered

Monday, February 6th 2017 – 23:00 UTC
Fall armyworm is native to the Americas and can devastate maize production, the staple food crop that is essential for food security in large areas of Africa.
Fall armyworm is native to the Americas and can devastate maize production, the staple food crop that is essential for food security in large areas of Africa.

New research announced by scientists at CABI (Center for Agriculture and Bioscience Information) confirms that a recently introduced crop-destroying armyworm caterpillar is now spreading rapidly across Mainland Africa and could spread to tropical Asia and the Mediterranean in the next few years, becoming a major threat to agricultural trade worldwide.

Fall armyworm is native to North and South America and can devastate maize production, the staple food crop that is essential for food security in large areas of Africa. It destroys young plants, attacking their growing points and burrowing into the cobs.

An indigenous pest in the Americas, it has not previously been established outside the region. In the past year, it was found in parts of West Africa for the first time and now a UK based CABI-led investigation has confirmed it to be present in Ghana. It can be expected to spread to the limits of suitable African habitat within a few years.

Plant doctors working in CABI’s Plantwise plant clinics, which work to help farmers lose less of what they grow, have found evidence of two species of fall armyworm in Ghana for the first time. This has been confirmed by DNA analysis undertaken at CABI’s molecular laboratory in Egham, Surrey (UK). In Africa, researchers are working to understand how it got there, how it spreads, and how farmers can control it in an environmentally friendly way.

CABI Chief Scientist, Dr. Matthew Cock said, “We are now able to confirm that the fall armyworm is spreading very rapidly outside the Americas, and it can be expected to spread to the limits of suitable African habitat within just a few years. It likely travelled to Africa as adults or egg masses on direct commercial flights and has since been spread within Africa by its own strong flight ability and carried as a contaminant on crop produce.”

Known as the fall armyworm because it migrates into temperate North America in Autumn (fall), this pest has long been a problem throughout tropical America, damaging vital crops. It mostly affects maize (corn) but it has been recorded eating more than 100 different plant species, causing major damage to economically important cultivated grass crops such as maize, rice, sorghum and sugarcane as well as other crops including cabbage, beet, peanut, soybean, alfalfa, onion, cotton, pasture grasses, millet, tomato, potato and cotton.

Following the first signs of a potential problem in Ghana in 2016, noted by plant clinic doctors, the CABI-led Plantwise initiative worked with the Plant Protection and Regulatory Services Directorate of the Ministry of Food and Agriculture, Ghana, to investigate the identity of the organism responsible and to determine if it was the first instance of fall armyworm being present in Ghana.

Damage to maize crops was investigated at three different survey areas within Ghana and the caterpillars associated with the damage were photographed, collected, and sent to the CABI laboratory in Egham, UK for analysis.

Dr. Cock explained, “Biological control for fall armyworm will need to be studied as the potential for Africa is not well understood yet. It may take several years to identify and test a suitable biological control for this pest in Africa so urgent work is needed right now. In the meantime, we will need to support national programmes to encourage the best types of pest control, and not resort to indiscriminate use of insecticides which are harmful to the environment and have limited success.”

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mersie

Dr. Wondi Mersie of Virginia State University, PI of the IPM Innovation Lab’s “Biological control of the invasive weed Parthenium hysterophorus in East Africa” project.

Feed the Future IPM Innovation Lab and Invasive Weed Species

The IPM Innovation Lab presented two papers at the “International Conference on Biodiversity, Climate Change Assessment and Impacts on Livelihood” in Kathmandu, Nepal. Dr. R. Muniappan, Director of the IPM Innovation Lab at Virginia Tech presented on the ecological distribution of the four alien invasive weed species, Ageratina adenophora, Chromolaena odorata, Lantana camara, and Parthenium hysterophorus. He pointed out the adoption of Ageratina adenophora to humid and temperate conditions, Chromolaena odorata to humid and tropical areas, and Parthenium hysterophorus to arid and tropical situations. However, several taxa of Lantana camara found in the tropics have adopted all the three conditions mentioned above.

Dr. Wondi Mersie of Virginia State University, PI of the IPM Innovation Lab’s “Biological control of the invasive weed Parthenium hysterophorus in East Africa” project, presented a paper on the adverse effect of Parthenium hysterophorus on biodiversity of above ground vegetation and the seed soil bank of rangelands in Ethiopia.

Stephanie Parker

IPM Innovation Lab

sparker1@vt.edu

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