Wheat rust in Ethiopia
Wheat rusts can devastate crop yields in Ethiopia, yet a new, wide-ranging partnership could lead to more effective crop protection across the country.
Wheat rusts are fungal diseases that can cause devastating losses to yields of the crop. In a country like Ethiopia, where wheat is a key part of the diet and of the economy, a poorly performing crop can have a huge impact.
Yet fungicides are only half the answer. Spray a field at the wrong time or in the wrong area, and not only will the crop still be at risk, the cost of the spray will have been wasted.
Spores of wheat rusts are spread by the wind, potentially over hundreds of kilometres. Other factors influencing this spread include rainfall and ultra-violet light affecting the deposition and lifetime of the spores as well the environmental conditions at the wheat rust locations and at the locations of crops down-wind.
Now, to help minimise the impact of wheat rusts in Ethiopia, the Met Office has joined forces with the University of Cambridge, the Ethiopian Institute of Agricultural Research (EIAR) and CIMMYT, the International Maize and Wheat Improvement Center. This is being made possible through funding from The Gates’ Foundation, Department for International Development (DFID) and the Biotechnology and Biological Sciences Research Council (BBSRC).
The partnership uses an atmospheric dispersion model to simulate the spread of the wheat rust spores to produce regular forecast maps to help farmers on the ground keep track of the most likely areas at risk from wheat rust. The current project aims to develop this further to provide a robust, routine feed of wheat rust forecasts to the authorities in Ethiopia. By knowing which way the spores are heading, farmers can take timely and appropriate action to save their crops.
The project began at the University of Cambridge, where graduate student Marcel Meyer is studying for a PhD, co-supervised by the Met Office, in the epidemiology of wheat rusts. Marcel used the Met Office’s Numerical Atmospheric dispersion Modelling Environment (NAME) to model the dispersion of rust spores by the wind and generate forecasts for the outbreaks.
Those forecasts led to a prototype system of reporting, whereby dispersion maps are sent to CIMMYT who compile a report to send out to Ethiopian farmers via government authorities. Anecdotal evidence suggests the report is already extremely popular on the ground.
The Met Office is now helping to develop the prototype and include other factors in the modelling, such as ultra-violet light decay of spores; meteorological dependence on the release of, and infection by, spores, thereby creating more detailed risk maps for farmers.
Sarah Millington is the manager of the Radiological and Biological team in the Atmospheric Dispersion and Air Quality group at the Met Office. Will Thurston, a scientist in her team, is leading the Met Office effort on the science and technology for the project. They are both excited by the opportunities that the work opens up.
“It’s all about impact on the ground,” says Sarah. We’re thinking about what we can produce that will help government agencies in Ethiopia make decisions and advise farmers directly.”
Experts in their fields
Up until now, wheat rust observations have been collected by government agencies and CIMMYT in Ethiopia. However, an interactive phone service enables farmers to dial in with reports of wheat rust outbreaks.
“Asking farmers to report on outbreaks is an extremely pragmatic solution,” explains Sarah. “Go out to Ethiopia and you’ll see farmers ploughing fields with oxen, but many have got mobile phones in their pockets.”
“Stem and yellow rust represent the greatest disease threat to Ethiopian wheat farmers; with both diseases capable of causing huge losses. Early warning is critical if good control is to be achieved. The NAME dispersal model has opened up new disease forecasting opportunities, which can result in awareness and control in farmers’ fields ahead of the advancing disease.”
Dave Hodson, Senior Scientist
International Maize and Wheat Improvement Center (CIMMYT-Ethiopia)
The data of wheat rust locations will be fed into NAME to produce large-scale dispersion outputs covering hundreds of kilometres. By then feeding these outputs into an epidemiology model at the University of Cambridge, the team will create maps of long and short-range potential wheat rust spread. They could be instrumental in helping farmers understand when and where they need to spray crops, ensuring better yields and less wastage of fungicide.
Once the two-year project is complete, Sarah and the project team hope that the work will continue. “We’ll be running training and workshops in Ethiopia,” she explains, “and a couple of scientists will come to the UK each year to better understand the science behind it.”
Although NAME has been used for modelling agricultural diseases and viruses before, what makes this project so unique is the wide variety of partners who are involved, from the Ethiopian farmers and Government to the Plant Sciences department at the University of Cambridge. All bring different expertise and practical knowledge to the table.
“No one group could do this by themselves,” adds Sarah. The pool of knowledge that it creates could make a large difference to farmers in Ethiopia. “It’s a really exciting project to work on and it’s good to know that the work has already had an impact,” says Sarah.