A new study of wheat rust--a fungal disease that can harm wheat crops--identifies previously unknown long-term trends and hotspots for wheat rust outbreaks in Ethiopia. A team of modelers from the University of Cambridge and the Universität Hamburg, along with surveillance experts from CIMMYT, EIAR and agricultural universities in Ethiopia, present these findings in the open-access journal PLOS ONE on February 3.
Ethiopia is a major wheat producer, and millions of its households rely on the crop as a source of income or sustenance. Wheat rust poses a significant threat to wheat production; outbreaks can lead to crop failure and boost risk of famine. Today, crop surveillance data fuels an early warning system for wheat rust outbreaks in the country, but a comprehensive understanding of past outbreaks has been lacking.
To fill this gap, Meyer and colleagues evaluated 13 years' worth of surveillance data from more than 13,000 fields across Ethiopia. They employed geographical analysis, statistical tools, and data-driven modeling to identify long-term, countrywide trends for the three types of wheat rust: stem, stripe, and leaf.
The analysis showed that all three types of wheat rust have contributed to recurrent outbreaks over the past decade, causing estimated economic losses of tens of millions of U.S. dollars per year. Each type poses increased risk in distinct geographical hotspots, and the two most common types (stem and stripe) display distinct directional trends in their prevalence. All three types vary in prevalence according to altitude.
The researchers also found evidence for a "boom-and-bust" outbreak cycle that may result from widespread adaptation of specific wheat varieties bred for genetic resistance to certain subtypes of wheat rust, only for resistance to break down or other subtypes to infect the crops.Click here to see more...