By Tracking the Weather, A New System Can Protect Brazilian Farmers from Wheat Blast
This post is written by Doug Johnson.
Every year, the spores of the wheat blast fungus lie in wait on South American and Bangladeshi farms. In most years, the pathogen has only a small impact on the countries’ wheat crops. But, the disease spreads quickly, and when the conditions are right, there’s a risk of a large outbreak — which can pose a serious threat to the food security and livelihood of farmers in a specific year.
To minimize this risk, an international partnership of researchers and organizations have created the wheat blast Early Warning System (EWS), a digital platform that notifies farmers and officials when weather conditions are ideal for the fungus to spread. The team is introducing the technology to Brazil. Wheat blast was originally discovered in the country in 1985.
The International Maize and Wheat Improvement Center (CIMMYT), the Brazilian Agricultural Research Corporation (EMBRAPA), Brazil’s University of Passo Fundo (UPF) and others developed the tool with support from USAID under the Cereal Systems Initiative for South Asia project. Although first developed for Bangladesh, the team is excited that the EWS is now endorsed and being used by agriculture workers in Brazil. The team hopes that the system will give farmers time to take preventative measures against wheat blast. Outbreaks can massively reduce crop yields if no preventative actions are taken.
“It can be very severe. It can cause a lot of damage,” says Maurício Fernandes, a plant epidemiologist with EMBRAPA.
In order to expand into a full outbreak, wheat blast requires specific temperature and humidity conditions. So, Fernandes and his team developed a digital platform that runs weather data through an algorithm to determine the times and places in which outbreaks are likely to occur.
If the system sees a region is going to grow hot and humid enough for the fungus to thrive, it sends an automated message to the agriculture workers in the area. These messages — texts or emails — alert them to take preemptive measures against the disease.
While over 6,000 extension agents in Bangladesh are signed up for disease early warnings, most farmers in Brazil are associated with cooperatives. Fernandes and his peers are connecting with these groups, which can send them weather data to help inform the EWS. The cooperatives can also spread these alerts through their websites or in-house applications.
Wheat blast can deform a plant quickly and, given the right conditions, even kill it. As such, these advanced warnings are essential to mitigate losses. The alerts sent out will recommend that farmers apply fungicide, which only works when applied before infection.
“If the pathogen has already affected the plant, the fungicides will have no effect,” Fernandes says.
A blast from the past
The cause of wheat blast, Magnaporthe oryzae, is also responsible for rice blast, and the pathogen likely jumped between the two crops. Because wheat had not previously been exposed to it, most wheat cultivars at the time had no natural resistance to Magnaporthe oryzae, according to Fernandes. Some newer varieties are moderately resistant to the disease, but the availability of sufficient seed for farmers remains limited.
The pathogen targets the wheat ear first, deforming it in less than a week after symptoms first appear. It can spread through leftover infected seeds and crop residue, but its spores can also travel vast distances through the air.
If the fungus spreads and infects enough plants, it can wreak havoc on nearby agriculture. In the 1990s — shortly after its discovery — wheat blast impacted around three million hectares of wheat in South America. Back in 2016, the disease appeared in Bangladesh and South Asia for the first time, and the resulting outbreak covered around 15,000 hectares of land. CGIAR estimates that the disease has the potential to reduce the region’s wheat production by 85 million tons.
In Brazil, wheat blast outbreaks can have a marked impact on the country’s agricultural output. During a major outbreak in 2009, the disease affected as many as three million hectares of crops in South America. As such, the EWS is an invaluable tool to support food security and farmer livelihoods. Fernandes also notes that affected regions can go multiple years between large outbreaks, but the threat remains.
“People forget about the disease, then you have an outbreak again,” he says.
The EWS has its roots in Brazil, but it took some time before the team launched it there. In 2017, Fernandes and his peers published a piece of research proposing the model. After that, Fernandes, Timothy Krupnik (a senior scientist and country representative with CIMMYT in Bangladesh involved with the project) and a slew of researchers and organizations launched a pilot project in Bangladesh.
There are more than 6,000 agriculture extension officers making use of the EWS the team developed for Bangladesh. Much like in Brazil, these officers receive an automated email or text message when weather conditions are ideal for wheat blast to thrive and spread. The team used this proof of concept to bring it back to Brazil, where the system was originally developed.
Krupnik notes that the Brazil platform is something of a “homecoming” for this work. He also noted that cooperation between the researchers, organizations and agriculture workers in Brazil and Bangladesh were instrumental in creating the system.
“From this, we’re able to have a partnership that I think will have a significant outcome in Brazil, from a relatively small investment in research supplied in Bangladesh. That shows you the power of partnerships and how solutions can be found to pressing agricultural problems through collaborative science, across continents,” he says.