Stem or black rust is a disease that hits basic agricultural crops such as wheat and barley. The potential for stem rust to affect the world's major wheat production regions has been identified in a series of reports. 31 studies by the UN Food and Agriculture Organisation ( the UN Food and Agriculture Organisation ) in 2017 found new strains of yellow and black rust had appeared in various parts of the world in 2016 , while older strains spread in Asia , Africa and Asia . Another study, published in Nature Plants in 2017 , confirmed Sailan was at risk of spreading wheat rust to these regions. The FAO estimated that 31 north and east African countries and Asia are responsible for 37% of wheat production worldwide.
The potential for stem rust to affect the world's major wheat production regions has been identified in a series of reports. 31 studies by the UN Food and Agriculture Organisation ( the UN Food and Agriculture Organisation ) in 2017 found new strains of yellow and black rust had appeared in various parts of the world in 2016 , while older strains spread in Asia , Africa and Asia . Another study, published in Nature Plants in 2017 , confirmed Sailan was at risk of spreading wheat rust to these regions. The FAO estimated that 31 north and east African countries and Asia are responsible for 37% of wheat production worldwide.