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Tag: plant diseases

Forests in the land of the Ese'eja Native Community of Infierno, in Peru's Madre de Dios department. (Photo: Yoly Gutierrez/CIFOR)

Safeguarding biodiversity is essential to prevent the next COVID-19

Written by Alison Doody on . Posted in Features. 11 Comments on Safeguarding biodiversity is essential to prevent the next COVID-19

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official views or position of the International Maize and Wheat Improvement Center (CIMMYT).

While the world’s attention is focused on controlling COVID-19, evidence points at the biodiversity crisis as a leading factor in its emergence. At first glance, the two issues might seem unrelated, but disease outbreaks and degraded ecosystems are deeply connected. FrĂ©dĂ©ric Baudron, systems agronomist at the International Maize and Wheat Improvement Center (CIMMYT) and Florian LiĂ©geois, virologist at the Institut de Recherche pour le DĂ©veloppement (IRD) share their insights on the current COVID-19 crisis and the link between biodiversity loss and emerging infectious diseases.

What trends are we seeing with infectious diseases like COVID-19?

We see that outbreaks of infectious diseases are becoming more frequent, even when we account for the so-called “reporting bias”: surveillance of such events becoming better with time and surveillance being better funded in the North than in the South.

60% of infectious diseases are zoonotic, meaning that they are spread from animals to humans and 72% of these zoonoses originate from wildlife. COVID-19 is just the last in a long list of zoonoses originating from wildlife. Other recent outbreaks include SARS, Ebola, avian influenza and swine influenza. As human activities continue to disturb ecosystems worldwide, we are likely to see more pathogens crossing from wildlife to humans in the future. This should serve as a call to better manage our relationship with nature in general, and wildlife in particular.

Researchers in Zimbabwe enter the cave dwelling of insectivorous bats (Hipposideros caffer) to conduct fecal sampling for viral research. (Photo: Florian Liégeois/IRD)
Researchers in Zimbabwe enter the cave dwelling of insectivorous bats (Hipposideros caffer) to conduct fecal sampling for viral research. (Photo: Florian Liégeois/IRD)

Why are we seeing more cases of diseases crossing from animals to humans? Where are they coming from?

Evidence points to bushmeat trade and consumption as the likely driver for the emergence of COVID-19. The emergence of SARS and Ebola was also driven by bushmeat consumption and trade. However, when looking at past outbreaks of zoonoses caused by a pathogen with a wildlife origin, land use changes, generally due to changes in agricultural practices, has been the leading driver.

Pathogens tends to emerge in well known “disease hotspots,” which tend to be areas where high wildlife biodiversity overlaps with high population density. These hotspots also tend to be at lower latitude. Interestingly, many of these are located in regions where CIMMYT’s activities are concentrated: Central America, East Africa and South Asia. This, in addition to the fact that agricultural changes are a major driver of the emergence of zoonoses, means that CIMMYT researchers may have a role to play in preventing the next global pandemic.

Smallholders clear forests for agriculture, but they also have an impact on forests through livestock grazing and fuelwood harvesting, as on this picture in Munesa forest, Ethiopia. (Photo: Frederic Baudron/CIMMYT)
Smallholders clear forests for agriculture, but they also have an impact on forests through livestock grazing and fuelwood harvesting, as on this picture in Munesa forest, Ethiopia. (Photo: Frederic Baudron/CIMMYT)

How exactly does biodiversity loss and land use change cause an increase in zoonotic diseases?

There are at least three mechanisms at play. First, increased contact between wildlife and humans and their livestock because of encroachment in ecosystems. Second, selection of wildlife species most able to infect humans and/or their livestock — often rodents and bats — because they thrive in human-dominated landscapes. Third, more pathogens being carried by these surviving wildlife species in simplified ecosystems. Pathogens tend to be “diluted” in complex, undisturbed, ecosystems.

The fast increase in the population of humans and their livestock means that they are interacting more and more frequently with wildlife species and the pathogens they carry. Today, 7.8 billion humans exploit almost each and every ecosystem of the planet. Livestock have followed humans in most of these ecosystems and are now far more numerous than wild vertebrates: there are 4.7 billion cattle, pigs, sheep and goats and 23.7 billion chickens on Earth! We live on an increasingly “cultivated planet,” with new species assemblages and new opportunities for pathogens to move from one species to another.

Wildlife trade and bushmeat consumption have received a lot of attention as primary causes of the spread of these viruses. Why has there been so little discussion on the connection with biodiversity loss?

The problem of biodiversity loss as a driver of the emergence of zoonoses is a complex one: it doesn’t have a simple solution, such as banning wet markets in China. It’s difficult to communicate this issue effectively to the public. It’s easy to find support for ending bushmeat trade and consumption because it’s easy for the public to understand how these can lead to the emergence of zoonoses, and sources of bushmeat include emblematic species with public appeal, like apes and pangolins. Bushmeat trafficking and consumption also gives the public an easy way to shift the blame: this is a local, rather than global, issue and for most of us, a distant one.

There is an inconvenient truth in the biodiversity crisis: we all drive it through our consumption patterns. Think of your annual consumption of coffee, tea, chocolate, sugar, textiles, fish, etc. But the biodiversity crisis is often not perceived as a global issue, nor as a pressing one. Media coverage for the biodiversity crisis is eight times lower than for the climate crisis.

The Unamat forest in Puerto Maldonado, Madre de Dios department, Peru. (Photo: Marco Simola/CIFOR)
The Unamat forest in Puerto Maldonado, Madre de Dios department, Peru. (Photo: Marco Simola/CIFOR)

Agriculture is a major cause of land use change and biodiversity loss. What can farmers do to preserve biodiversity, without losing out on crop yields?

Farming practices that reduce the impact of agriculture on biodiversity are well known and form the foundation of sustainable intensification, for which CIMMYT has an entire program. A better question might be what we can do collectively to support them in doing so. Supportive policies, like replacing subsidies by incentives that promote sustainable intensification, and supportive markets, for example using certification and labeling, are part of the solution.

But these measures are likely to be insufficient alone, as a large share of the global food doesn’t enter the market, but is rather consumed by the small-scale family farmers who produce it.

Reducing the negative impact of food production on biodiversity is likely to require a global, concerted effort similar to the Paris Agreements for climate. As the COVID-19 pandemic is shocking the world, strong measures are likely to be taken globally to avoid the next pandemic. There is a risk that some of these measures will go too far and end up threatening rural livelihoods, especially the most vulnerable ones. For example, recommending “land sparing” — segregating human activities from nature by maximizing yield on areas as small as possible —  is tempting to reduce the possibility of pathogen spillover from wildlife species to humans and livestock. But food production depends on ecosystem services supported by biodiversity, like soil fertility maintenance, pest control and pollination. These services are particularly important for small-scale family farmers who tend to use few external inputs.

How can we prevent pandemics like COVID-19 from happening again in the future?

There is little doubt that new pathogens will emerge. First and foremost, we need to be able to control emerging infectious diseases as early as possible. This requires increased investment in disease surveillance and in the health systems of the countries where the next infectious disease is most likely to emerge. In parallel, we also need to reduce the frequency of these outbreaks by conserving and restoring biodiversity globally, most crucially in disease hotspots.

Farming tends to be a major driver of biodiversity loss in these areas but is also a main source of livelihoods. The burden of reducing the impact of agriculture on biodiversity in disease hotspots cannot be left to local farmers, who tend to be poor small-scale farmers: it will have to be shared with the rest of us.

Cover photo: Forests in the land of the Ese’eja Native Community of Infierno, in Peru’s Madre de Dios department. (Photo: Yoly Gutierrez/CIFOR)

Hans Braun, Director of the Global Wheat Program at the International Maize and Wheat Improvement Center (CIMMYT), inspects wheat plants in the greenhouses. (Photo: Alfonso Cortés/CIMMYT)

Crossing boundaries

Written by Marta Millere on . Posted in Features.

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official views or position of the International Maize and Wheat Improvement Center (CIMMYT).

Daily life as we know it has grinded to a halt and crop scientists are pondering next steps in face of the global COVID-19 crisis. Hans Braun, Director of the Global Wheat Program at the International Maize and Wheat Improvement Center (CIMMYT) and the CGIAR Research Program on Wheat, joins us for a virtual chat to discuss the need for increased investment in crop disease research as the world risks a food security crisis.

What have you learned from your work on contagious wheat diseases that we can take away during this time?

Wheat epidemics go back to biblical times. Wheat scientists now believe Egypt’s “seven bad years” of harvest referenced in the Bible were due to a stem rust outbreak.

So, we know what happens when we have a crop epidemic: diseases can completely wipe out a harvest. I have seen subsistence farmers stand in front of their swaying, golden wheat fields, but there is not a single grain inside the spikes. All because of wheat blast.

There are a lot of parallel issues that I see with COVID-19.

The epidemiology models for humans which we see now have a lot in common with plant epidemiology. For example, if you take a wheat field sown with a variety which is rust-resistant and then you get a spore which mutates and overcomes the resistance — like COVID-19 overcomes the human immune system — it then takes about two weeks for it to sporulate again and produce millions of these mutated spores. They sporulate once more and then you have billions and trillions of spores — then the wheat fields at the local, national and, in the worst case, regional level are severely damaged and in worst case are going to die.

The problem is that since we cannot quarantine wheat, if the weather is favorable these spores will fly everywhere and — just like with COVID-19 — they don’t need a passport to travel.

Could you elaborate on that? How can wheat diseases go global?

Usually it takes around 5 years, sometimes less, until a mutation in a rust spore can overcome the resistance of a wheat variety. Every so often, we see rust epidemics which cover an entire region. To monitor this movement, the Borlaug Global Rust Initiative of Cornell University and CIMMYT, funded by the Bill & Melinda Gates Foundation and DFID, established a global rust monitoring system that provides live data on spore movements.

For example, if you have a new race of stem rust in Yemen — and in Yemen wheat matures early — and then farmers burn the straw, their action “pushes” the spores up into the air, thus allowing them to enter the jet stream and cover 2,000 to 5,000 kilometers in a short period of time. Spores can also be carried on clothes or shoes by people who walked into an infected wheat field. Take Australia, for example, which has very strict quarantine laws. It is surrounded by sea and still eventually they get the new rust races which fly around or come with travelers. One just cannot prevent it.

Stem rust resistant (left) and susceptible (right) wheat plants at the stem rust phenotyping facility in Njoro, Nakuru County in Kenya. (Photo: Joshua Masinde/CIMMYT)
Stem rust resistant (left) and susceptible (right) wheat plants at the stem rust phenotyping facility in Njoro, Nakuru County in Kenya. (Photo: Joshua Masinde/CIMMYT)

Could climate change exacerbate the spreading of crop diseases?

Yes, the climate and its variability have a lot to do with it. For example, in the case of yellow rust, what’s extremely important is the time it takes from sporulation to sporulation. Take a rust spore. It germinates, then it grows, it multiplies and then once it is ready it will disperse and infect wheat plants. From one dispersal to the next it takes about two weeks.

In the last decades, in particular for yellow rust, new races are better adapted to high temperature and are multiplying faster. In a Nature paper, we showed that 30 years ago yellow rust was not present in the Great Plains in the US. Today, it is the most important wheat disease there. So there really is something going on and changing and that’s why we are so concerned about new wheat disease races when they come up.

What could an epidemiologist specialized in human viruses take from this?

Well, I think human epidemiologists know very well what happens in a case like COVID-19. Ordinary citizens now also start to understand what a pandemic is and what its related exponential growth means.

Maybe you should ask what policymakers can learn from COVID-19 in order to prevent plant epidemics. When it comes to epidemics, what applies to humans applies to plants. If there is a new race of a given crop disease, in that moment, the plant does not have a defense mechanism, like humans in the case of COVID-19, because we haven’t developed any immunity. While in developed countries farmers can use chemicals to control plant diseases, resource-poor farmers do not have this option, due to lack to access or if the plant protective has not been registered in their country.

In addition to this, our lines of work share a sense of urgency. If “doomsday” happens, it will be too late to react. At present, with a human pandemic, people are worried about the supply chain from food processing to the supermarket. But if we have an epidemic in plants, then we do not have the supply chain from the field to the food processing industry. And if people have nothing to eat, they will go to the streets and we will see violence. We simply cannot put this aside.

What other lessons can policymakers and other stakeholders take away from the current crisis?

The world needs to learn that we cannot use economics as the basis for disease research. We need to better foresee what could happen.

Let’s take the example of wheat blast, a devastating disease that can destroy the wheat spike and was initially confined to South America. The disease arrived in Bangladesh in 2016 and caused small economic damage, maybe 30,000 tons loss in a small geographic area — a small fraction of the national production but a disaster for the smallholder farmer, who thus would have lost her entire wheat harvest. The disease is now controlled with chemicals. But what if chemical resistance is developed and the disease spreads to the 10 million hectares in the Indo-Gangetic Plains of India and the south of Pakistan. Unlikely? But what if it happens?

Agriculture accounts for 30% of the global GDP and the research money [going to agriculture] in comparison to other areas is small. Globally only 5% of R&D is invested in research for development related to agriculture. Such a discrepancy! A million U.S. dollars invested in wheat blast research goes a long way and if you don’t do it, you risk a disaster.

If there is any flip side to the COVID-19 disaster, it is that hopefully our governments realize that they have to play a much more serious role in many areas, in particular public health and disease control in humans but also in plants.

A Lloyd’s report concluded that a global food crisis could be caused by governments taking isolating actions to protect their own countries in response to a breadbasket failure elsewhere. I’m concerned that as the COVID-19 crisis continues, governments will stop exports as some did during the 2008 food price crisis, and then, even if there is enough food around, the 2008 scenario might happen again and food prices will go through the roof, with disastrous impact on the lives of the poorest.

This article was originally published by the CGIAR Research Program on Wheat (WHEAT):
Crossing boundaries: looking at wheat diseases in times of the COVID-19 crisis.

Cover photo: Hans Braun, Director of the Global Wheat Program at the International Maize and Wheat Improvement Center (CIMMYT), inspects wheat plants in the greenhouses. (Photo: Alfonso Cortés/CIMMYT)

Pests and diseases and climate change: Is there a connection?

Written by Alison Doody on . Posted in Features. 4 Comments on Pests and diseases and climate change: Is there a connection?

Responsible for 80% of the food we eat and 98% of the oxygen we breathe, plants are a pillar of life on earth. But they are under threat. Up to 40 percent of food crops are lost to plant pests and diseases each year according to the FAO.

When disease outbreaks occur, the impacts can be devastating. In the 1840s, the Irish potato famine, caused by the fungal disease late blight, killed around one million people and caused another million to emigrate.

The recent invasion of desert locusts throughout the horn of Africa – the worst in decades – shows how vulnerable crops are to pests as well.

The desert locust is one of the most destructive pests in the world, with one small swarm covering one square kilometer eating the same amount of food per day as 35,000 people. The outbreak could even provoke a humanitarian crisis, according to the FAO.

How does climate change affect pests and diseases?

Climate change is one factor driving the spread of pests and diseases, along with increasing global trade.  Climate change can affect the population size, survival rate and geographical distribution of pests; and the intensity, development and geographical distribution of diseases.

Temperature and rainfall are the big drivers of shifts in how and where pests and diseases spread, according to experts.

“In general, an increase in temperature and precipitation levels favors the growth and distribution of most pest species by providing a warm and humid environment and providing necessary moisture for their growth,” says Tek Sapkota, agricultural systems and climate change scientist at the International Maize and Wheat Improvement Center (CIMMYT).

However, when temperatures and precipitation levels get too high, this can slow the growth and reproduction of some pest species and destroy them by washing their eggs and larvae off the host plant, he explains.

This would explain why many pests are moving away from the tropics towards more temperate areas. Pests like warmer temperatures – but up to a point. If it is too hot or too cold, populations grow more slowly. Since temperate regions are not currently at the optimal temperature for pests, populations are expected to grow more quickly in these areas as they warm up.

Crop diseases are following a similar pattern, particularly when it comes to pathogens like fungi.

Movement towards the earth’s poles

Research shows that since 1960, crop pests and diseases have been moving at an average of 3 km a year in the direction of the earth’s north and south poles as temperatures increase.

Tar spot, a fungal disease native to Latin America, which can cause up to 50% of yield losses in maize, was detected for the first time in the US in 2015. Normally prevalent in tropical climates, the disease has started emerging in non-tropical regions, including highland areas of Central Mexico and many counties in the US.

Maize-producing counties in the USA vulnerable to tar spot complex (TSC) calculated based on climate similarity. Khondoker Mottaleb et al. 2018

The southern pine beetle, one of the most destructive insects invading North America, is moving north as temperatures rise and is likely to spread throughout northeastern United States and into southeastern Canada by 2050.

Wheat stem rust was reported by the Greeks and Romans, and the latter sacrificed to the gods to avoid disease outbreaks on their wheat crops. Photo: CIMMYT/Petr Kosina

Wheat rusts, which are among the greatest threats to wheat production around the world, are also adapting to warmer climates and becoming more aggressive in nature, says Mandeep Randhawa, CIMMYT wheat breeder and wheat rust pathologist.

“As temperatures rise, larger quantities of spores are produced that can cause further infection and could potentially result in pathogenic changes through faster rate of their evolution.”

Scientists recently reported that stem rust had emerged in the UK for the first time in 60 years. Climate changes over the past 25 years are likely to have encouraged conditions for infection, according to the study.

Rising CO2 levels

Rising carbon dioxide (CO2) levels could also affect pests indirectly, by changing the architecture of their host plant and weakening its defenses.

“Elevated CO2 concentrations, as a result of human activity and influence on climate change, will most likely influence pests indirectly through the modification in plant chemistry, physiology and nutritional content,” says Leonardo Crespo, CIMMYT wheat breeder.

Rising CO2 concentrations and temperatures could also provide a more favorable environment for pathogens like fungi, reports the International Panel on Climate Change (IPCC).

Despite high confidence among scientists that climate change will cause an increase in pests and diseases, predicting exactly when and where pests and diseases will spread is no easy task. There is significant variation between different species of pests and types of pathogens, and climate models can only provide estimates of where infection or outbreaks might occur.

Keeping pests and disease pandemics at bay

To address these uncertainties, experts increasingly recognize the need to monitor pest and disease outbreaks and have called for a global surveillance system to monitor these and improve responses.

Recent technological tools like the suitcase-sized mobile lab MARPLE, which tests pathogens such as wheat rust in near real-time and gives results within 48 hours, allow for early detection. Early warning systems are also crucial tools to warn farmers, researchers and policy makers of potential outbreaks.

Breeding pest- and disease-resistant varieties is another environmentally friendly solution, since it reduces the need for pesticides and fungicides. Collaborating with scientists worldwide, CIMMYT works on developing wheat and maize varieties resistant to diseases, including Fusarium Head Blight (FHB), wheat rust, wheat blast for wheat and maize lethal necrosis (MLN) for maize.

A ladybug (or ladybird) beetle sits on a wheat spike of an improved variety growing in the field in Islamabad, Pakistan. Photo credit: A. Yaqub/CIMMYT.

Beneficial insects can also act as a natural pest control for crops. Ladybugs, spiders and dragonflies act as natural predators for pests like aphids, caterpillars and stem borers. Other solutions include mechanical control measures such as light traps, pheromone traps and sticky traps, as well as farming practice controls such as crop rotation.

The United Nations has declared this year as the International Year of Plant Health, emphasizing the importance of raising global awareness on how “protecting plant health can help end hunger, reduce poverty, protect biodiversity and the environment, and boost economic development.”

As part of this initiative, CIMMYT will host the 24th Biannual International Plant Resistance to Insects (IPRI) conference from March 2-4. The conference will cover topics including plant-insect interactions, breeding for resistance, and phenotyping technologies for predicting pest resistant traits in plants.

Cover photo: A locust swarm in north-east Kenya. The UN Food and Agriculture Organization has warned that the swarms already seen in Somalia, Kenya and Ethiopia could range further afield. Photograph: Sven Torfinn/FAO

What is wheat blast?

Written by Matthew O'Leary on . Posted in Explainers. 7 Comments on What is wheat blast?

What is wheat blast disease?

Wheat blast is a fast-acting and devastating fungal disease that threatens food safety and security in tropical areas in South America and South Asia. Directly striking the wheat ear, wheat blast can shrivel and deform the grain in less than a week from the first symptoms, leaving farmers no time to act.

The disease, caused by the fungus Magnaporthe oryzae pathotype triticum (MoT), can spread through infected seeds and survives on crop residues, as well as by spores that can travel long distances in the air.

Magnaporthe oryzae can infect many grasses, including barley, lolium, rice, and wheat, but specific isolates of this pathogen generally infect limited species; that is, wheat isolates infect preferably wheat plants but can use several more cereal and grass species as alternate hosts. The Bangladesh wheat blast isolate is being studied to determine its host range. The Magnaporthe oryzae genome is well-studied but major gaps remain in knowledge about its epidemiology.

The pathogen can infect all aerial wheat plant parts, but maximum damage is done when it infects the wheat ear. It can shrivel and deform the grain in less than a week from first symptoms, leaving farmers no time to act.
The pathogen can infect all aerial wheat plant parts, but maximum damage is done when it infects the wheat ear. It can shrivel and deform the grain in less than a week from first symptoms, leaving farmers no time to act.

Where is wheat blast found?

First officially identified in Brazil in 1985, the disease is widespread in South American wheat fields, affecting as much as 3 million hectares in the early 1990s. It continues to seriously threaten the potential for wheat cropping in the region.

In 2016, wheat blast spread to Bangladesh, which suffered a severe outbreak. It has impacted around 15,000 hectares of land in eight districts, reducing yield on average by as much as 51% in the affected fields.

Wheat-producing countries and presence of wheat blast.
Wheat-producing countries and presence of wheat blast.

How does blast infect a wheat crop?

Wheat blast spreads through infected seeds, crop residues as well as by spores that can travel long distances in the air.

Blast appears sporadically on wheat and grows well on numerous other plants and crops, so rotations do not control it. The irregular frequency of outbreaks also makes it hard to understand or predict the precise conditions for disease development, or to methodically select resistant wheat lines.

At present blast requires concurrent heat and humidity to develop and is confined to areas with those conditions. However, crop fungi are known to mutate and adapt to new conditions, which should be considered in management efforts.

How can farmers prevent and manage wheat blast?

There are no widely available resistant varieties, and fungicides are expensive and provide only a partial defense. They are also often hard to obtain or use in the regions where blast occurs, and must be applied well before any symptoms appear — a prohibitive expense for many farmers.

The Magnaporthe oryzae fungus is physiologically and genetically complex, so even after more than three decades, scientists do not fully understand how it interacts with wheat or which genes in wheat confer durable resistance.

Researchers from the International Maize and Wheat Improvement Center (CIMMYT) are partnering with national researchers and meteorological agencies on ways to work towards solutions to mitigate the threat of wheat blast and increase the resilience of smallholder farmers in the region. Through the USAID-supported Cereal Systems Initiative for South Asia (CSISA) and Climate Services for Resilient Development (CSRD) projects, CIMMYT and its partners are developing agronomic methods and early warning systems so farmers can prepare for and reduce the impact of wheat blast.

CIMMYT works in a global collaboration to mitigate the threat of wheat blast, funded by the Australian Centre for International Agricultural Research (ACIAR), the CGIAR Research Program on Wheat (WHEAT), the Indian Council of Agricultural Research (ICAR) and the Swedish Research Council (VetenskapsrĂ„det). Some of the partners who collaborate include the Bangladesh Wheat and Maize Research Institute (BWMRI), Bolivia’s Instituto Nacional de InnovaciĂłn Agropecuaria y Forestal (INIAF), Kansas State University and the Agricultural Research Service of the US (USDA-ARS).

Agricultural solutions to tackle humanity’s climate crisis

Written by Mike Listman on . Posted in Features.

More than 11,000 scientists signed on to a recent report showing that planet Earth is facing a climate emergency and the United Nations warned that the world is on course for a 3.2 degree spike by 2100, even if 2015 Paris Agreement commitments are met.

Agriculture, forestry, and land-use change are implicated in roughly a quarter of global greenhouse gas emissions.

Agriculture also offers opportunities to mitigate climate change and to help farmers — particularly smallholders in developing and emerging economies who have been hardest hit by hot weather and reduced, more erratic rainfall.

Most of CIMMYT’s work relates to climate change, helping farmers adapt to shocks while meeting the rising demand for food and, where possible, reducing emissions.

Family farmer Geofrey Kurgat (center) with his mother Elice Tole (left) and his nephew Ronny Kiprotich in their 1-acre field of Korongo wheat near Belbur, Nukuru, Kenya. (Photo: Peter Lowe/CIMMYT)
Family farmer Geofrey Kurgat (center) with his mother Elice Tole (left) and his nephew Ronny Kiprotich in their 1-acre field of Korongo wheat near Belbur, Nukuru, Kenya. (Photo: Peter Lowe/CIMMYT)

Climate-resilient crops and farming practices

53 million people are benefiting from drought-tolerant maize. Drought-tolerant maize varieties developed using conventional breeding provide at least 25% more grain than other varieties in dry conditions in sub-Saharan Africa — this represents as much as 1 ton per hectare more grain on average. These varieties are now grown on nearly 2.5 million hectares, benefiting an estimated 6 million households or 53 million people in the continent. One study shows that drought-tolerant maize can provide farming families in Zimbabwe an extra 9 months of food at no additional cost. The greatest productivity results when these varieties are used with reduced or zero tillage and keeping crop residues on the soil, as was demonstrated in southern Africa during the 2015-16 El Niño drought. Finally, tolerance in maize to high temperatures in combination with drought tolerance has a benefit at least twice that of either trait alone.

Wheat yields rise in difficult environments. Nearly two decades of data from 740 locations in more than 60 countries shows that CIMMYT breeding is pushing up wheat yields by almost 2% each year — that’s some 38 kilograms per hectare more annually over almost 20 years — under dry or otherwise challenging conditions. This is partly through use of drought-tolerant lines and crosses with wild grasses that boost wheat’s resilience. An international consortium is applying cutting-edge science to develop climate-resilient wheat. Three widely-adopted heat and drought-tolerant wheat lines from this work are helping farmers in Pakistan, a wheat powerhouse facing rising temperatures and drier conditions; the most popular was grown on an estimated 40,000 hectares in 2018.

Climate-smart soil and fertilizer management. Rice-wheat rotations are the predominant farming system on more than 13 million hectares in the Indo-Gangetic Plains of South Asia, providing food and livelihoods for hundreds of millions. If farmers in India alone fine-tuned crop fertilizer dosages using available technologies such as cellphones and photosynthesis sensors, each year they could produce nearly 14 million tons more grain, save 1.4 million tons of fertilizer, and cut CO2-equivalent greenhouse gas emissions by 5.3 million tons. Scientists have been studying and widely promoting such practices, as well as the use of direct seeding without tillage and keeping crop residues on the soil, farming methods that help capture and hold carbon and can save up to a ton of CO2 emissions per hectare, each crop cycle. Informed by CIMMYT researchers, India state officials seeking to reduce seasonal pollution in New Delhi and other cities have implemented policy measures to curb the burning of rice straw in northern India through widespread use of zero tillage.

Farmers going home for breakfast in Motoko district, Zimbabwe. (Photo: Peter Lowe/CIMMYT)
Farmers going home for breakfast in Motoko district, Zimbabwe. (Photo: Peter Lowe/CIMMYT)

Measuring climate change impacts and savings

In a landmark study involving CIMMYT wheat physiologists and underlining nutritional impacts of climate change, it was found that increased atmospheric CO2 reduces wheat grain protein content. Given wheat’s role as a key source of protein in the diets of millions of the poor, the results show the need for breeding and other measures to address this effect.

CIMMYT scientists are devising approaches to gauge organic carbon stocks in soils. The stored carbon improves soil resilience and fertility and reduces its emissions of greenhouse gases. Their research also provides the basis for a new global soil information system and to assess the effectiveness of resource-conserving crop management practices.

CIMMYT scientist Francisco Pinto operates a drone over wheat plots at CIMMYT's experimental station in Ciudad Obregon, Mexico. (Photo: Alfonso Cortés/CIMMYT)
CIMMYT scientist Francisco Pinto operates a drone over wheat plots at CIMMYT’s experimental station in Ciudad Obregon, Mexico. (Photo: Alfonso CortĂ©s/CIMMYT)

Managing pests and diseases

Rising temperatures and shifting precipitation are causing the emergence and spread of deadly new crop diseases and insect pests. Research partners worldwide are helping farmers to gain an upper hand by monitoring and sharing information about pathogen and pest movements, by spreading control measures and fostering timely access to fungicides and pesticides, and by developing maize and wheat varieties that feature genetic resistance to these organisms.

Viruses and moth larvae assail maize. Rapid and coordinated action among public and private institutions across sub-Saharan Africa has averted a food security disaster by containing the spread of maize lethal necrosis, a viral disease which appeared in Kenya in 2011 and quickly moved to maize fields regionwide. Measures have included capacity development with seed companies, extension workers, and farmers the development of new disease-resilient maize hybrids.

The insect known as fall armyworm hit Africa in 2016, quickly ranged across nearly all the continent’s maize lands and is now spreading in Asia. Regional and international consortia are combating the pest with guidance on integrated pest management, organized trainings and videos to support smallholder farmers, and breeding maize varieties that can at least partly resist fall armyworm.

New fungal diseases threaten world wheat harvests. The Ug99 race of wheat stem rust emerged in eastern Africa in the late 1990s and spawned 13 new strains that eventually appeared in 13 countries of Africa and beyond. Adding to wheat’s adversity, a devastating malady from the Americas known as “wheat blast” suddenly appeared in Bangladesh in 2016, causing wheat crop losses as high as 30% on a large area and threatening to move quickly throughout South Asia’s vast wheat lands.

In both cases, quick international responses such as the Borlaug Global Rust Initiative, have been able to monitor and characterize the diseases and, especially, to develop and deploy resistant wheat varieties.

A community volunteer of an agricultural cooperative (left) uses the Plantix smartphone app to help a farmer diagnose pests in his maize field in Bardiya district, Nepal. (Photo: Bandana Pradhan/CIMMYT)
A community volunteer of an agricultural cooperative (left) uses the Plantix smartphone app to help a farmer diagnose pests in his maize field in Bardiya district, Nepal. (Photo: Bandana Pradhan/CIMMYT)

Partners and funders of CIMMYT’s climate research

A global leader in publicly-funded maize and wheat research and related farming systems, CIMMYT is a member of CGIAR and leads the South Asia Regional Program of the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).

CIMMYT receives support for research relating to climate change from national governments, foundations, development banks and other public and private agencies. Top funders include CGIAR Research Programs and Platforms, the Bill & Melinda Gates Foundation, Mexico’s Secretary of Agriculture and Rural Development (SADER), the United States Agency for International Development (USAID), the UK Department for International Development (DFID), the Australian Centre for International Agricultural Research (ACIAR), Cornell University, the German aid agency GIZ, the UK Biotechnology and Biological Sciences Research Council (BBSRC), and CGIAR Trust Fund Contributors to Window 1 &2.

Scientists develop an early warning system that delivers wheat rust predictions directly to farmers’ phones

Written by Rodrigo Ordóñez on . Posted in Press releases.

One of the researchers behind the study, Yoseph Alemayehu, carries out a field survey in Ethiopia by mobile phone. (Photo Dave Hodson/CIMMYT)
One of the researchers behind the study, Yoseph Alemayehu, carries out a field survey in Ethiopia by mobile phone. (Photo Dave Hodson/CIMMYT)

TEXCOCO, Mexico — Using field and mobile phone surveillance data together with forecasts for spore dispersal and environmental suitability for disease, an international team of scientists has developed an early warning system which can predict wheat rust diseases in Ethiopia. The cross-disciplinary project draws on expertise from biology, meteorology, agronomy, computer science and telecommunications.

Reported this week in Environmental Research Letters, the new early warning system, the first of its kind to be implemented in a developing country, will allow policy makers and farmers all over Ethiopia to gauge the current situation and forecast wheat rust up to a week in advance.

The system was developed by the University of Cambridge, the UK Met Office, the Ethiopian Institute of Agricultural Research (EIAR), the Ethiopian Agricultural Transformation Agency (ATA) and the International Maize and Wheat Improvement Center (CIMMYT). It works by taking near real-time information from wheat rust surveys carried out by EIAR, regional research centers and CIMMYT using a smartphone app called Open Data Kit (ODK).

This is complemented by crowd-sourced information from the ATA-managed Farmers’ Hotline. The University of Cambridge and the UK Met Office then provide automated 7-day advance forecast models for wheat rust spore dispersal and environmental suitability based on disease presence.

All of this information is fed into an early warning unit that receives updates automatically on a daily basis. An advisory report is sent out every week to development agents and national authorities. The information also gets passed on to researchers and farmers.

Example of weekly stripe rust spore deposition based on dispersal forecasts. Darker colors represent higher predicted number of spores deposited. (Graphic: University of Cambridge/UK Met Office)
Example of weekly stripe rust spore deposition based on dispersal forecasts. Darker colors represent higher predicted number of spores deposited. (Graphic: University of Cambridge/UK Met Office)

Timely alerts

“If there’s a high risk of wheat rust developing, farmers will get a targeted SMS text alert from the Farmers’ Hotline. This gives the farmer about three weeks to take action,” explained Dave Hodson, principal scientist with CIMMYT and co-author of the research study. The Farmers’ Hotline now has over four million registered farmers and extension agents, enabling rapid information dissemination throughout Ethiopia.

Ethiopia is the largest wheat producer in sub-Saharan Africa but the country still spends in excess of $600 million annually on wheat imports. More can be grown at home and the Ethiopian government has targeted to achieve wheat self-sufficiency by 2023.

“Rust diseases are a grave threat to wheat production in Ethiopia. The timely information from this new system will help us protect farmers’ yields, and reach our goal of wheat self-sufficiency,” said EIAR Director Mandefro Nigussie.

Wheat rusts are fungal diseases that can be dispersed by wind over long distances, quickly causing devastating epidemics which can dramatically reduce wheat yields. Just one outbreak in 2010 affected 30% of Ethiopia’s wheat growing area and reduced production by 15-20%.

The pathogens that cause rust diseases are continually evolving and changing over time, making them difficult to control. “New strains of wheat rust are appearing all the time — a bit like the flu virus,” explained Hodson.

In the absence of resistant varieties, one solution to wheat rust is to apply fungicide, but the Ethiopian government has limited supplies. The early warning system will help to prioritize areas at highest risk of the disease, so that the allocation of fungicides can be optimized.

Example of weekly stripe rust environmental suitability forecast. Yellow to Brown show the areas predicted to be most suitable for stripe rust infection. (Graphic: University of Cambridge/UK Met Office)
Example of weekly stripe rust environmental suitability forecast. Yellow to Brown show the areas predicted to be most suitable for stripe rust infection. (Graphic: University of Cambridge/UK Met Office)

The cream of the crop

The early warning system puts Ethiopia at the forefront of early warning systems for wheat rust. “Nowhere else in the world really has this type of system. It’s fantastic that Ethiopia is leading the way on this,” said Hodson. “It’s world-class science from the UK being applied to real-world problems.”

“This is an ideal example of how it is possible to integrate fundamental research in modelling from epidemiology and meteorology with field-based observation of disease to produce an early warning system for a major crop,” said Christopher Gilligan, head of the Epidemiology and Modelling Group at the University of Cambridge and a co-author of the paper, adding that the approach could be adopted in other countries and for other crops.

“The development of the early warning system was successful because of the great collaborative spirit between all the project partners,” said article co-author Clare Sader-Allen, currently a regional climate modeller at the British Antarctic Survey.

“Clear communication was vital for bringing together the expertise from a diversity of subjects to deliver a common goal: to produce a wheat rust forecast relevant for both policy makers and farmers alike.”

RELATED PUBLICATIONS:

An early warning system to predict and mitigate wheat rust diseases in Ethiopia
https://doi.org/10.1088/1748-9326/ab4034

INTERVIEW OPPORTUNITIES:

Dave Hodson, Senior Scientist, International Maize and Wheat Improvement Center (CIMMYT)

FOR MORE INFORMATION, OR TO ARRANGE INTERVIEWS, CONTACT:

Marcia MacNeil, Communications Officer, CIMMYT. m.macneil@cgiar.org, +52 (55) 5804 2004 ext. 2070.

Rodrigo Ordóñez, Communications Manager, CIMMYT. r.ordonez@cgiar.org, +52 (55) 5804 2004 ext. 1167.

ACKNOWLEDGEMENTS:

This study was made possible through the support provided by the BBSRC GCRF Foundation Awards for Global Agriculture and Food Systems Research, which brings top class UK science to developing countries, the Delivering Genetic Gains in Wheat (DGGW) Project managed by Cornell University and funded by the Bill & Melinda Gates Foundation and the UK Department for International Development (DFID). The Government of Ethiopia also provided direct support into the early warning system. This research is supported by CGIAR Fund Donors.

ABOUT CIMMYT:

The International Maize and Wheat Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and related farming systems. Headquartered near Mexico City, CIMMYT works with hundreds of partners throughout the developing world to sustainably increase the productivity of maize and wheat cropping systems, thus improving global food security and reducing poverty. CIMMYT is a member of the CGIAR System and leads the CGIAR Research Programs on Maize and Wheat and the Excellence in Breeding Platform. The Center receives support from national governments, foundations, development banks and other public and private agencies. For more information, visit staging.cimmyt.org.

ABOUT THE ETHIOPIAN INSTITUTE OF AGRICULTURAL RESEARCH (EIAR):

The Ethiopian Institute of Agricultural Research (EIAR) is one of the oldest and largest agricultural research institutes in Africa, with roots in the Ethiopian Agricultural Research System (EARS), founded in the late 1940s. EIAR’s objectives are: (1) to generate, develop and adapt agricultural technologies that focus on the needs of the overall agricultural development and its beneficiaries; (2) to coordinate technically the research activities of Ethiopian Agricultural Research System; (3) build up a research capacity and establish a system that will make agricultural research efficient, effective and based on development needs; and (4) popularize agricultural research results. EIAR’s vision is to see improved livelihood of all Ethiopians engaged in agriculture, agro-pastoralism and pastoralism through market competitive agricultural technologies.

Smallholder farmers’ multi-front strategy combats rapidly evolving wheat rust in Ethiopia

Written by Leslie Domínguez on . Posted in News. 1 Comment on Smallholder farmers’ multi-front strategy combats rapidly evolving wheat rust in Ethiopia

 

Ethiopian wheat planting. (Photo: CIMMYT)

New research shows that smallholder farmers in Ethiopia used various coping mechanisms apart from fungicides in response to the recent wheat rust epidemics in the country. Scientists from the International Maize and Wheat Improvement Center (CIMMYT) and the Ethiopian Institute of Agricultural Research (EIAR) call for continuous support to research and extension programs to develop and disseminate improved wheat varieties with resistant traits to old and newly emerging rust races.

Rising wheat yields cannot catch up rising demand

Wheat is the fourth largest food crop in Ethiopia cultivated by smallholders, after teff, maize and sorghum. Ethiopia is the largest wheat producer in sub-Saharan Africa and average farm yields have more than doubled in the past two decades, reaching 2.74 tons per hectare on average in 2017/18. Farmers who use improved wheat varieties together with recommended agronomic practices recorded 4 to 6 tons per hectare in high-potential wheat growing areas such as the Arsi and Bale zones. Yet the country remains a net importer because demand for wheat is rapidly rising.

The Ethiopian government has targeted wheat self-sufficiency by 2023 and the country has huge production potential due to its various favorable agroecologies for wheat production.

However, one major challenge to boosting wheat production and yields is farmers’ vulnerability to rapidly evolving wheat diseases like wheat rusts.

The Ethiopian highlands have long been known as hot spots for stem and yellow wheat rusts caused by the fungus Puccinia spp., which can spread easily under favorable climatic conditions. Such threats may grow with a changing climate.

Recurrent outbreaks of the two rusts destroyed significant areas of popular wheat varieties. In 2010, a yellow rust epidemic severely affected the popular Kubsa variety. In 2013/14, farmers in the Arsi and Bale zones saw a new stem rust race destroy entire fields of the bread wheat Digalu variety.

In response to the 2010 yellow rust outbreak, the government and non-government organizations, seed enterprises and other development supporters increased the supply of yellow rust resistant varieties like Kakaba and Danda’a.

Fungicide is not the only solution for wheat smallholder farmers

Two household panel surveys during the 2009/10 main cropping season, before the yellow rust epidemic, and during the 2013/14 cropping season analyzed farmers’ exposure to wheat rusts and their coping mechanisms. From the survey, 44% of the wheat farming families reported yellow rust in their fields during the 2010/11 epidemic.

Household data analysis looked at the correlation between household characteristics, their coping strategies against wheat rust and farm yields. The study revealed there was a 29 to 41% yield advantage by increasing wheat area of the new, resistant varieties even under normal seasons with minimum rust occurrence in the field. Continuous varietal development in responding to emerging new rust races and supporting the deployment of newly released rust resistant varieties could help smallholders cope against the disease and maintain improved yields in the rust prone environments of Ethiopia.

The case study showed that apart from using fungicides, increasing wheat area under yellow rust resistant varieties, increasing diversity of wheat varieties grown, or a combination of these strategies were the main coping mechanisms farmers had taken to prevent new rust damages. Large-scale replacement of highly susceptible varieties by new rust resistant varieties was observed after the 2010/11 epidemic.

The most significant wheat grain yield increases were observed for farmers who increased both area under resistant varieties and number of wheat varieties grown per season.

The additional yield gain thanks to the large-scale adoption of yellow rust resistant varieties observed after the 2010/11 epidemic makes a very strong case to further strengthen wheat research and extension investments, so that more Ethiopian farmers have access to improved wheat varieties resistant to old and newly emerging rust races.

Read the full study on PLOS ONE:
https://doi.org/10.1371/journal.pone.0219327

Color-infrared image of maize hybrids in the experimental trials under fungicide treatment (A1) and non-fungicide treatment (A2) of tar spot complex of maize. Image data were extracted from two polygons from the two central rows in each plot (B).

Bird’s-eye view

Written by Carolyn Cowan on . Posted in Features.

Francelino Rodrigues prepares an UAV for radiometric calibration for multispectral flight over a maize tar spot complex screening trial at CIMMYT’s Agua Fría experimental station, Mexico. (Photo: Alexander Loladze/CIMMYT)
Francelino Rodrigues prepares an UAV for radiometric calibration for multispectral flight over a maize tar spot complex screening trial at CIMMYT’s Agua Fría experimental station, Mexico. (Photo: Alexander Loladze/CIMMYT)

A new study from researchers at the International Maize and Wheat Improvement Center (CIMMYT) shows that remote sensing can speed up and improve the effectiveness of disease assessment in experimental maize plots, a process known as phenotyping.

The study constitutes the first time that unmanned aerial vehicles (UAVs, commonly known as drones) with cameras that capture non-visible electromagnetic radiation were used to assess tar spot complex on maize.

The interdisciplinary team found among other things that potential yield losses under heavy tar spot complex infections could reach 58% — more than 10% greater than reported in previous studies.

Caused by the interaction of two fungal pathogens that thrive in warm, humid conditions, tar spot complex is diagnosed by the telltale black spots that cover infected plants. (Photo: Alexander Loladze/CIMMYT)
Caused by the interaction of two fungal pathogens that thrive in warm, humid conditions, tar spot complex is diagnosed by the telltale black spots that cover infected plants. (Photo: Alexander Loladze/CIMMYT)

“Plant disease resistance assessment in the field is becoming difficult because breeders’ trials are larger, are conducted at multiple locations, and there is a lack of personnel trained to evaluate diseases,” said Francelino Rodrigues, CIMMYT precision agriculture specialist and co-lead author of the study. “In addition, disease scoring based on visual assessments can vary from person to person.”

A major foliar disease that affects maize throughout Latin America, tar spot complex results from the interaction of two species of fungus that thrive in warm, humid conditions. The disease causes telltale black spots on infected plants, killing leaves, weakening the plant, and impairing ear development.

Phenotyping has traditionally involved breeders walking through crop plots and visually assessing each plant, a labor-intensive and time-consuming process. As remote sensing technologies become more accessible and affordable, scientists are applying them more often to assess experimental plants for desired agronomic or physical traits, according to Rodrigues, who said they can facilitate accurate, high-throughput phenotyping for resistance to foliar diseases in maize and help reduce the cost and time of developing improved maize germplasm.

“To phenotype maize for resistance to foliar diseases, highly trained personnel must spend hours in the field to complete visual crop evaluations, which requires substantial time and resources and may result in biased or inaccurate results between surveyors,” said Rodrigues. “The use of UAVs to gather multispectral and thermal images allows researchers to cut down the time and expenses of evaluations, and perhaps in the future it could also improve accuracy.”

Color-infrared image of maize hybrids in the experimental trials under fungicide treatment (A1) and non-fungicide treatment (A2) of tar spot complex of maize. Image data were extracted from two polygons from the two central rows in each plot (B).
Color-infrared image of maize hybrids in the experimental trials under fungicide treatment (A1) and non-fungicide treatment (A2) of tar spot complex of maize. Image data were extracted from two polygons from the two central rows in each plot (B).

Technology sheds new light on phenotyping

Receptors in the human eye detect a limited range of wavelengths in the electromagnetic spectrum — the area we call visible light — consisting of three bands that our eyes perceive as red, green and blue. The colors we see are the combination of the three bands of visible light that an object reflects.

Remote sensing takes advantage of how the surface of a leaf differentially absorbs, transmits and reflects light or other electromagnetic radiation, depending on its composition and condition. The reflectance of diseased plant tissue is different from that of healthy ones, provided the plants are not stressed by other factors, such as heat, drought or nutrient deficiencies.

In this study, researchers planted 25 tropical and subtropical maize hybrids of known agronomic performance and resistance to tar spot complex at CIMMYT’s experimental station in Agua Fría, central Mexico. They then carried out disease assessments by eye and gathered multispectral and thermal imagery of the plots.

This allowed them to compare remote sensing with traditional phenotyping methods. Calculations revealed a strong relationship between grain yield, canopy temperature, vegetation indices and the visual assessment.

Future applications

“The results of the study suggest that remote sensing could be used as an alternative method for assessment of disease resistance in large-scale maize trials,” said Rodrigues. “It could also be used to calculate potential losses due to tar spot complex.”

Accelerated breeding for agriculturally relevant crop traits is fundamental to the development of improved varieties that can face mounting global agricultural threats. It is likely that remote sensing technologies will have a critical role to play in overcoming these challenges.

“An important future area of research encompasses pre-symptomatic detection of diseases in maize,” explained Rodrigues. “If successful, such early detection would allow appropriate disease management interventions before the development of severe epidemics. Nevertheless, we still have a lot of work to do to fully integrate remote sensing into the breeding process and to transfer the technology into farmers’ fields.”

Funding for this research was provided by the CGIAR Research Program on Maize (MAIZE).  

Read the full article:
Loladze A, Rodrigues FA Jr, Toledo F, San Vicente F, GĂ©rard B and Boddupalli MP (2019) Application of Remote Sensing for Phenotyping Tar Spot Complex Resistance in Maize. Front. Plant Sci. 10:552. doi: 10.3389/fpls.2019.00552

STMA meeting participants pose for a group photo during a field visit to seed company Zamseeds. (Photo: Jerome Bossuet/CIMMYT)

Shifting to a demand-led maize improvement agenda

Written by Jennifer Johnson on . Posted in Features.

Partners of the Stress Tolerant Maize for Africa (STMA) project held their annual meeting May 7–9, 2019, in Lusaka, Zambia, to review the achievements of the past year and to discuss the priorities going forward. Launched in 2016, the STMA project aims to develop multiple stress-tolerant maize varieties for diverse agro-ecologies in sub-Saharan Africa, increase genetic gains for key traits preferred by the smallholders, and make these improved seeds available at scale in the target countries in partnership with local public and private seed sector partners.

The project, funded by the Bill & Melinda Gates Foundation and the United States Agency for International Development (USAID), is led by the International Maize and Wheat Improvement Center (CIMMYT), and implemented together with the International Institute for Tropical Agriculture (IITA), national agricultural research systems and seed company partners in 13 countries in sub-Saharan Africa.

The meeting was officially opened by the Deputy Director of the Zambia Agriculture Research Institute (ZARI), Monde Zulu. “Maize in Africa faces numerous challenges such as drought, heat, pests and disease. Thankfully, these challenges can be addressed through research. I would like to take this opportunity to thank CIMMYT and IITA. Your presence here is a testament of your commitment to improve the livelihoods of farmers in sub-Saharan Africa,” she said.

The International Maize and Wheat Improvement Center (CIMMYT) and its partners are working together in the fight against challenges such as drought, maize lethal necrosis and fall armyworm. The STMA project applies innovative technologies such as high-throughput phenotyping, doubled haploids, marker-assisted breeding and intensive germplasm screening to develop improved stress-tolerant maize varieties for smallholder farmers. The project team is also strengthening maize seed systems in sub-Saharan Africa through public-private partnerships.

The efforts are paying off: in 2018, 3.5 million smallholder farmers planted stress-tolerant maize varieties in 10 African countries.

The deputy director of the Zambia Agriculture Research Institute (ZARI), Monde Zulu (fourth from left), gives the opening address of the STMA Annual Meeting 2019. Left to right: Mick Mwala, University of Zambia; Tony Cavalieri, Bill & Melinda Gates Foundation; B.M. Prasanna, CIMMYT; Monde Zulu, ZARI; Mwansa Kabamba, ZARI; Cosmos Magorokosho, CIMMYT; and Abebe Menkir, IITA.
The deputy director of the Zambia Agriculture Research Institute (ZARI), Monde Zulu (fourth from left), gives the opening address of the STMA Annual Meeting 2019. Left to right: Mick Mwala, University of Zambia; Tony Cavalieri, Bill & Melinda Gates Foundation; B.M. Prasanna, CIMMYT; Monde Zulu, ZARI; Mwansa Kabamba, ZARI; Cosmos Magorokosho, CIMMYT; and Abebe Menkir, IITA.

Yielding results

CIMMYT researcher and STMA project leader Cosmos Magorokosho reminded the importance of maize in the region. “Maize is grown on over 35 million hectares in sub-Saharan Africa, and more than 208 million farmers depend on it as a staple crop. However, average maize yields in sub-Saharan Africa are among the lowest in the world.” Magorokosho pointed out that the improved maize varieties developed through the project “provide not only increased yields but also yield stability even under challenging conditions like drought, poor soil fertility, pests and diseases.”

“STMA has proved that it is possible to combine multiple stress tolerance and still get good yields,” explained B.M. Prasanna, director of CIMMYT’s Global Maize Program and the CGIAR Research Program on Maize (MAIZE). “One of the important aspects of STMA are the partnerships which have only grown stronger through the years. We are the proud partners of national agricultural research systems and over 100 seed companies across sub-Saharan Africa.”

Keynote speaker Hambulo Ngoma of the Indaba Agricultural Policy Research Institute (IAPRI) addressed the current situation of maize in Zambia, where farmers are currently reeling from recent drought. “Maize is grown by 89% of smallholder farmers in Zambia, on 54% of the country’s cultivable land, but productivity remains low. This problem will be exacerbated by expected population growth, as the population of Zambia is projected to grow from over 17 million to 42 million by 2050,” he said.

STMA meeting participants pose for a group photo during the field visit to QualiBasic Seed. (Photo: Jennifer Johnson/CIMMYT)
STMA meeting participants pose for a group photo during the field visit to QualiBasic Seed. (Photo: Jennifer Johnson/CIMMYT)

Down to business

On May 8, participants visited three partner local seed companies to learn more about the opportunities and challenges of producing improved maize seed for smallholder farmers.

Afriseed CEO Stephanie Angomwile discussed her business strategy and passion for agriculture with participants. She expressed her gratitude for the support CIMMYT has provided to the company, including access to drought-tolerant maize varieties as well as capacity development opportunities for her staff.

Bhola Nath Verma, principal crop breeder at Zamseed, explained how climate change has a visible impact on the Zambian maize sector, as the main maize growing basket moved 500 km North due to increased drought. Verma deeply values the partnership with the STMA project, as he can source drought-tolerant breeding materials from CIMMYT and IITA, allowing him to develop early-maturing improved maize varieties that escape drought and bring much needed yield stability to farmers in Angola, Botswana, the Democratic Republic of the Congo, Tanzania and Zambia.

At QualiBasic Seed, STMA partners were given the opportunity to learn and ask questions about the company’s operations, including the seed multiplication process in Zambia and the importance of high-quality, genetically pure foundation seed for seed companies.

Emmanuel Angomwile (left) and Stephanie Angomwile (center) answer visitors’ questions at their seed company, Afriseed. (Photo: Jennifer Johnson/CIMMYT)
Emmanuel Angomwile (left) and Stephanie Angomwile (center) answer visitors’ questions at their seed company, Afriseed. (Photo: Jennifer Johnson/CIMMYT)

Young ideas

The meeting concluded with an awards ceremony for the winners of the 2019 MAIZE Youth Innovators Awards – Africa, established by MAIZE in collaboration with the Young Professionals for Agricultural Development (YPARD). These awards recognize the contributions of young women and men under 35 who are implementing innovations in African maize-based agri-food systems, including research-for-development, seed systems, agribusiness, and sustainable intensification. This is the second year of the MAIZE Youth Awards, and the first time it has been held in Africa. Winners include Hildegarde Dukunde of Rwanda and Mila Lokwa Giresse of the Democratic Republic of the Congo in the change agent category, Admire Shayanowako of the Republic of South Africa and Ismael Mayanja of Uganda in the research category, and Blessings Likagwa of Malawi in the farmer category.

Winners of the 2019 MAIZE Youth Innovators Awards – Africa receive their awards at the STMA meeting in Lusaka, Zambia. From left to right: Admire Shayanowako, Blessings Likagwa, Ismael Mayanja and Hildegarde Dukunde. Fifth awardee Mila Lokwa Giresse not pictured. (Photo: J.Bossuet/CIMMYT)
Winners of the 2019 MAIZE Youth Innovators Awards – Africa receive their awards at the STMA meeting in Lusaka, Zambia. From left to right: Admire Shayanowako, Blessings Likagwa, Ismael Mayanja and Hildegarde Dukunde. Fifth awardee Mila Lokwa Giresse not pictured. (Photo: J.Bossuet/CIMMYT)

New infographics illustrate impact of wheat blast

Written by Marcia MacNeil on . Posted in Infographics.

Wheat blast is a fast-acting and devastating fungal disease that threatens food safety and security in the Americas and South Asia.

First officially identified in Brazil in 1984, the disease is widespread in South American wheat fields, affecting as much as 3 million hectares in the early 1990s.

In 2016, it crossed the Atlantic Ocean, and Bangladesh suffered a severe outbreak. Bangladesh released a blast-resistant wheat variety — developed with breeding lines from the International Maize and Wheat Improvement Center (CIMMYT) — in 2017, but the country and region remain extremely vulnerable.

The continued spread of blast in South Asia — where more than 100 million tons of wheat are consumed each year — could be devastating.

Researchers with the CIMMYT-led and USAID-supported Cereal Systems Initiative for South Asia (CSISA) and Climate Services for Resilient Development (CSRD) projects partner with national researchers and meteorological agencies on ways to work towards solutions to mitigate the threat of wheat blast and increase the resilience of smallholder farmers in the region. These include agronomic methods and early warning systems so farmers can prepare for and reduce the impact of wheat blast.

This series of infographics shows how wheat blast spreads, its potential effect on wheat production in South Asia and ways farmers can manage it.

blastinfographic1

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blastinfographic3

This work is funded by the U.S. Agency for International Development (USAID) and the Bill & Melinda Gates Foundation. CSISA partners include CIMMYT, the International Food Policy Research Institute (IFPRI) and the International Rice Research Institute (IRRI).

CIMMYT and its partners work to mitigate wheat blast through projects supported by the U.S. Agency for International Development (USAID), the Bill & Melinda Gates Foundation, the Australian Centre for International Agricultural Research (ACIAR), the Indian Council for Agricultural Research (ICAR), the CGIAR Research Program on WHEAT and the CGIAR Platform for Big Data in Agriculture.

Learn more about wheat blast.

This article was originally published on the website of the CGIAR Research Program on Wheat.

Delegates of the 3-year review conference pose for a group photograph at the ICRAF Campus in Nairobi. (Photo: Joshua Masinde/CIMMYT)

International coalition keeps devastating maize disease at bay, but risks still linger

Written by JĂ©rĂŽme Bossuet on . Posted in Features.

NAIROBI, Kenya (CIMMYT) — When maize lethal necrosis (MLN) was first reported in Bomet County, Kenya, in September 2011 and spread rapidly to several countries in eastern Africa, agricultural experts feared this emerging maize disease would severely impact regional food security. However, a strong partnership across eight countries between maize research, plant health organizations and the private seed sector has, so far, managed to contain this devastating viral disease, which can wipe out entire maize fields. As another emerging pest, the fall armyworm, is making headlines in Africa, African countries could learn a lot from the initiatives to combat MLN on how to rapidly respond to emerging crop pests and diseases.

On November 19-20, 2018, the International Maize and Wheat Improvement Center (CIMMYT), national research and plant protection agencies and seed companies met in Nairobi to review the third year’s progress of the MLN Diagnostics and Management Project, supported by USAID. All participants agreed that preventing any spread of the disease into southern Africa was a great success.

“The fact that we all responded rapidly and productively to this crisis serves as a testament of the success of our collective efforts,” said CIMMYT’s Global Maize Program Director, B.M. Prasanna, while addressing delegates from Ethiopia, Kenya, Malawi, Rwanda, Tanzania, Uganda, Zambia and Zimbabwe. “That no new country has reported the MLN outbreak since Ethiopia last reported it in the 2014-2015 period, and that we have managed to keep it at bay from southern Africa and west Africa is no mean feat. It would have been a major food security disaster if the disease had spread throughout sub-Saharan Africa.”

However, the MLN Community of Practice warned that risks of severe outbreaks remain, with new cases of MLN reported during the MLN 2018 survey in several parts of Uganda.

Delegates from Rwanda discuss the country's workplan at the 3-year MLN project review. (Photo: Joshua Masinde/CIMMYT)
Delegates from Rwanda discuss the country’s workplan at the 3-year MLN project review. (Photo: Joshua Masinde/CIMMYT)

Rapid response to a food security threat

MLN is caused by the combination of the maize chlorotic mottle virus (MCMV) and other common cereal viruses mostly from the potyviridae family — a set of viruses that encompasses over 30 percent of known plant viruses — like the sugarcane mosaic virus (SCMV). This viral disease can result in up to 100 percent yield loss and has devastated the incomes and food security situation of many smallholder farmers in the region.

CIMMYT, in collaboration with national agricultural research institutions, national plant protection agencies and seed sector partners, developed a multi-layered response system including real-time intensive surveillance, screening, and fast-tracking of the MLN resistance breeding program. Thanks to the MLN Screening Facility in Naivasha, Kenya, maize breeders rapidly discovered that most popular maize varieties were susceptible, which could expose poor farmers to the risk of losing their entire maize crops.

Using its global collection of maize lines and numerous crop improvement innovations, CIMMYT was able to develop and release at least 15 MLN-resistant maize varieties in just 2 to 3 years.

One important step was to understand how the disease spread. Epidemiologists quickly pointed out the necessity to work with the seed companies and farmers, as the virus could be transmitted through seeds. The project helped put in place the protocols for seed firms to adhere to for their products to be MLN-free. Affordable and simple seed treatment procedures yielded promising results. The project also created awareness on better farming methods for effective disease control.

National Plant Protection Organizations were mobilized to create intensive awareness. They were also equipped and trained on low-cost innovative field diagnostic tools like MLN immunostrips and the deployment of GPS-based mobile surveillance and reporting systems.

“For the first time, Rwanda was able to conduct a comprehensive survey on MLN in farmers’ fields, commercial seed fields and at agro-dealers. We are glad that through MLN management and awareness programs within the project, MLN incidences have declined,” said Fidele Nizeyimana, maize breeder and pathologist at the Rwanda Agricultural Board (RAB) and the MLN Surveillance team lead in Rwanda.

“Equally important is that the commercial seed sector took the responsibility of testing their seed production fields, made sure that seed exchange is done in a responsible manner and implemented voluntary monitoring and surveillance within their fields,” remarked Francis Mwatuni, MLN project manager at CIMMYT.

“I am happy that Malawi has maintained its MLN-free status as per the intensive MLN surveillance activities we conducted in the country over the last three years,” noted Johnny Masangwa, senior research officer and MLN Surveillance team lead in Malawi. “We are now able to monitor both seed and grain movement through our borders for MLN traces, courtesy of the lab equipment, reagents and training on laboratory analysis we received through the project”.

B.M. Prasanna, director of the CGIAR Research Program on Maize (MAIZE), discusses what the CGIAR offers in rapid response preparedness to newly emerging pests, diseases and crises.

The maize sector should remain vigilant

Daniel Bomet, maize breeder at Uganda’s National Agricultural Research Organization (NARO), warned that with new infections reported in the northern parts of his country, the maize sector needs to remain alert to the threat of MLN. “We need to step up MLN awareness and management programs, and require seed companies to follow the right procedures to produce MLN-free seeds to arrest this trend,” he said.

Tanzania Seed Association Executive Director, Bob Shuma, also warned that MLN could be spreading to the southern highlands of the country as the virus was detected in some seed shipments from three seed companies operating in that region. A comprehensive MLN survey in Tanzania will hopefully soon give an idea of the countrywide status of the disease in the country.

Conference speakers and participants noted that inefficient regulatory processes in maize seed variety release and deployment still stand in the way of rapid release of MLN resistant varieties to farmers across the region.

“How quickly we scale up and deploy the elite MLN-resistant and stress-tolerant varieties to the farmer is the next most important phase of the project,” Prasanna said.

The Kenya Plant Health Inspectorate Service (KEPHIS) General Manager, Phytosanitary Services, Isaac Macharia, said that with the support of the USAID Feed the Future program, the government agency has set up a team dedicated to assisting seed companies doing seed multiplication to fast-track the release of the MLN-resistant varieties to the market. Some Kenyan seed companies announced they will market MLN-resistant varieties for the next cropping season in March 2019.

As the project enters its last year, the MLN Community of Practice looks to ensure the fully functional pest surveillance and management system it has put in place is sustainable beyond the project’s life.

CIMMYT researchers Dave Hodson (left) and Francis Mwatuni (center) discuss MLN issues with another delegate during the 3-year MLN project review workshop. (Photo: Joshua Masinde/CIMMYT)
CIMMYT researchers Dave Hodson (left) and Francis Mwatuni (center) discuss MLN issues with another delegate during the 3-year MLN project review workshop. (Photo: Joshua Masinde/CIMMYT)

Cobs & Spikes podcast: Matthew Rouse discusses research on wheat diseases

Written by on . Posted in Podcasts.

This week the International Maize and Wheat Improvement Center (CIMMYT) launched a new podcast: Cobs & Spikes. This is a space where we’re going to break down complex science into bite-sized, audio-rich explainers. We’re going to have real conversations with experts from around the world who are innovating in the fields of agriculture, food security and nutrition. We’re also going to listen to stories that link CIMMYT’s research with real-world applications.

In this episode, we are celebrating World Food Day, October 16. Also this week, food experts and leaders from around the world are gathering in Iowa for the 2018 Borlaug Dialogue and the World Food Prize Laureate Award Ceremony.

Today we’re talking to the recipient of the World Food Prize 2018 Norman Borlaug Award for Field Research and Application.

Matthew Rouse is a researcher with the Agricultural Research Service of the United States Department of Agriculture. Rouse works on developing wheat varieties that are resistant to diseases, and he’s being recognized for his work on Ug99 — a devastating race of stem rust disease. Throughout his career, Rouse has collaborated with the International Maize and Wheat Improvement Center (CIMMYT).

Music credit: Loam by Podington Bear

You can subscribe to Cobs & Spikes on SoundCloud, iTunes, Stitcher and other podcast platforms.

See our coverage of the 2018 Borlaug Dialogue and the World Food Prize.
See our coverage of the 2018 Borlaug Dialogue and the World Food Prize.

New publications: Toxin-producing fungal strains can now be detected in maize field soils with a new technique

Written by Carolyn Cowan on . Posted in Publications.

A novel approach allows the detection of aflatoxin-producing fungi in maize fields. A new study explains the technique and how it was tested. “Detection of Aflatoxigenic and Atoxigenic Mexican Aspergillus Strains by the Dichlorvos–Ammonia (DV–AM) Method” was developed in collaboration between scientists from the International Maize and Wheat Improvement Center (CIMMYT), the Japanese National Agriculture and Food Organization (NARO) and Fukui University of Technology, funded in part by the CGIAR Research Program on Maize (MAIZE).

Aflatoxins are harmful compounds produced by the fungi Aspergillus flavus, which can be found in the soil, plants and grain of a variety of cereals and commodities including maize, nuts, cottonseed, spices and dried fruit. The toxic carcinogenic qualities of aflatoxins pose serious health hazards to humans and animals when contaminated crops are ingested. These health risks include cancers of the liver and gallbladder, stunted development in children, premature births and abnormal fetal development.

Not all strains of A. flavus produce aflatoxins however, so it is important to be able to detect and distinguish between A. flavus strains that are benign (atoxigenic) and those that produce dangerous toxins (aflatoxigenic). Current methods of detection are often complicated by the fact that the fungal strains display very similar physiological and molecular traits, thus a new approach is required.

In the study, a novel approach to detect and distinguish A. flavus strains was tested. Using soil samples from a CIMMYT experimental maize field in Mexico, fungal isolates were chemically treated in-line with a method recently developed in Japan, resulting in a color change indicative of toxicity. The method was found to be effective and accurate in the detection of the aflatoxigenic strains of the fungus.

This study is foundational work in the development of a simple, cost-effective and efficient method of detecting aflatoxigenic strains of A. flavus, which will help inform growers about the potential aflatoxin contamination of their crops. This is of particular importance in the developing world, where the resources for effective control of the fungus are often lacking.

To read the original study, “Detection of Aflatoxigenic and Atoxigenic Mexican Aspergillus Strains by the Dichlorvos–Ammonia (DV–AM) Method”, please click here.

Original citation: Kushiro, M.; Hatabayashi, H.; Yabe, K.; Loladze, A. Detection of Aflatoxigenic and Atoxigenic Mexican Aspergillus Strains by the Dichlorvos–Ammonia (DV–AM) Method. Toxins 2018, 10, 263.

This article was originally published on the website of the CGIAR Research Program on Maize.

Maize ear infected with Aspergillus flavus. (Photo: Maize Pathology Laboratory/CIMMYT)
Maize ear infected with Aspergillus flavus. (Photo: Maize Pathology Laboratory/CIMMYT)

Check out other recent publications by CIMMYT researchers below:

  1. Genetic analysis of tropical midaltitude-adapted maize populations under stress and nonstress conditions. 2018. Makumbi, D., Assanga, S., Diallo, A., Magorokosho, C., Asea, G., Regasa, M.W., BĂ€nziger, M. In: Crop Science v. 58, no. 4, p. 1492-1507.
  2. Interactions among genes Sr2/Yr30, Lr34/Yr18/Sr57 and Lr68 confer enhanced adult plant resistance to rust diseases in common wheat (Triticum aestivum L.) line ‘Arula’. 2018.  Randhawa, M.S., Caixia Lan, Basnet, B.R., Bhavani, S., Huerta-Espino, J., Forrest, K.L., Hayden, M., Singh, R.P. In: Australian Journal of Crop Science v. 12, no. 6, p. 1023-1033.
  3. Practical breeding strategies to improve resistance to Septoria tritici blotch of wheat. 2018. Tabib Ghaffary, S.M., Chawade, A., Singh, P.K. In: Euphytica v. 214, art. 122.
  4. Sashaydiall : A SAS program for hayman’s diallel analysis. 2018. Makumbi, D., Alvarado BeltrĂĄn, G., Crossa, J., Burgueño, J. In: Crop Science v. 58, no. 4, p. 1605-1615.
  5. Soil bacterial diversity under conservation agriculture-based cereal systems in indo-gangetic plains. 2018. Choudhary, M., Sharma, P.C., Jat, H. S., Dash, A., Rajashekar, B., McDonald, A., Jat, M.L.  In: 3 Biotech v. 8, art. 304.
Artificial inoculation of maize germplasm at the Naivasha MLN screening site, Kenya. (Photo: B.Wawa/CIMMYT)

New online portal offers information to curb maize lethal necrosis in Africa

Written by on . Posted in News.

Artificial inoculation of maize germplasm at the Naivasha MLN screening site, Kenya. (Photo: B.Wawa/CIMMYT)
Artificial inoculation of maize germplasm at the Naivasha MLN screening site, Kenya. (Photo: B.Wawa/CIMMYT)

The new maize lethal necrosis (MLN) online portal provides up-to-date information and surveillance tools to help researchers control and stop the spread of the deadly disease.

MLN was first reported in Kenya in 2011 and has since then been reported in several countries in eastern Africa, especially the Democratic Republic of the Congo, Ethiopia, Kenya, Rwanda, Tanzania and Uganda. The disease kills plants before they can grow, and the pathogens are transmitted by insects or contaminated seed. Serious damage to the region’s maize production from MLN has impacted household food security.

The online portal, found at mln.cimmyt.org, details the spread of MLN, where the disease has been managed and controlled, and how to identify it in the field. It also provides key MLN publications, surveillance software, MLN incidence maps, information on the MLN Screening Facility, and MLN-tolerant hybrids that are either released or in pipeline.

One tool on the portal is the MLN surveillance and monitoring system that provides real-time data to identify the presence and spread of the disease across five endemic countries in eastern Africa, and three selected non-endemic countries in southern Africa. The system was developed by scientists collaborating with the International Maize and Wheat Improvement Center (CIMMYT), with support from the United States Agency for International Development (USAID).

In 2016, MLN surveillance was successfully conducted in Malawi, Zambia and Zimbabwe – three major seed producing countries in Africa – and the data is presented in the portal, detailing MLN’s status across 652 surveyed maize fields. Future data gathered in other affected countries will also be uploaded to the portal as surveillance teams conduct fieldwork using Global Positioning System online survey tools, to assess the spread and severity of the disease in these countries. Ongoing surveillance in endemic countries allows stakeholders to see real-time updates on the spread of MLN.

MLN susceptible hybrids compared to a CIMMYT-derived MLN-tolerant hybrid. Photo: CIMMYT
MLN susceptible hybrids compared to a CIMMYT-derived MLN-tolerant hybrid. Photo: CIMMYT

Since the disease was first reported, collaborative efforts have resulted in the establishment of a MLN Screening Facility at the Kenya Agricultural & Livestock Research Organization (KALRO) center at Naivasha in 2013. The facility, managed by CIMMYT, has so far screened nearly 100,000 maize germplasm entries — 56 percent from CIMMYT — against MLN under artificial inoculation over the last four years.

Nine CIMMYT-derived MLN-tolerant hybrids have been already released in three countries – seven in Kenya, one in Uganda and one in Tanzania. Eleven second generation hybrids are currently in national performance trials in these countries. Intensive efforts are currently being made by seed companies in Kenya, Tanzania and Uganda to expand the delivery of MLN-tolerant maize seed to the smallholders.

The MLN portal enables researchers to comprehensively assess the situation with regard to MLN, helps strengthen the national disease monitoring and diagnostic systems by providing faster and accurate data, and offers access to CIMMYT-offered MLN phenotyping services.