Major crop disease outbreaks

Disease epidemics are an on-going concern


Symptoms of wheat blast
CC BY-SA 4.0
2016-17WheatWheat BlastBangladesh
First emergence of wheat blast in Asia. Average disease losses of 30%. Total crop loss in some cases.

Image: Institute of Plant Virology, Italy
2014OliveXylella fastidosaSouthern EuropeOver 1 million trees infected, up to 40% rise in olive oil prices. Olive oil production in Tuscany reduced by half.

MLN-Infected Maize
2011MaizeMaize lethal necrosis diseaseEast AfricaDisease widespread across maize growing areas. Estimated national losses of 10% per year. Individual losses up to 100%.

CC BY-SA 2.0 by CIAT
2012CoffeeRustCentral America
Over $1 billion in damage to coffee plants. Up to 500,000 job losses. Many farms lost over 75% of production.

Photo: Jeff Ellis
2010WheatStripe rustAsia
North America
Epidemic causing 40% losses.

CC BY 2.0 by USDAgov
2010sCitrusGreening diseaseFloridaMassive impact on Florida citurs industry with no good control methods available. Up to 75% of trees in southeast US infected.
1999WheatStem rustEast Africa
Middle East
New race (Ug99) spreading throughout Africa and Middle East, threatening world supply.

Valencia citrus canker 1d
CC BY-SA 2.0
Scot Nelson
1990s-2000sCitrusCankerFloridaUnsuccessful tree eradication program abandoned in 2006.

Scot Nelson
Papaya ringspot (PRSV) 9
CC BY-SA 2.0  
1990sPapayaRing spot virusHawaiiNearly led to collapse of papaya industry. GM variety introduced widely credited with saving the industry.

Scot Nelson
Banana Panama wilt 2

CC BY-SA 2.0
1990sBananaPanama disease tropical race 4Southeast AsiaCurrently threatening to wipe out the Cavendish banana.

Link (CC BY 2.0)  
1989CacaoWitches' broomBrazilLosses up to 100%. Overall wiped out 75% of production.

CC BY-SA 2.0 by CIAT
1975CoffeeRustCentral America
South America
First report of growing outbreak that continues today.

Eric McKenzie
Pest and Disease Image Library, Australia
CC BY 3.0 Link
1970CornSouthern corn leaf blightUSAScattered in 1968-69. Full scale epidemic in 1970 due to wide use of a single susceptible corn background.

Bacterial leaf blight  
 by IRRI Images
1960sRiceBacterial leaf blightSoutheast AsiaYield losses up to 80%.

Donald Groth, Louisiana State University AgCenter
CC BY 3.0, Link
1942RiceBrown spot diseaseIndiaFactor in Great Bengal Famine. 2 million people died of starvation.
1935, 1953WheatStem rustNorth AmericaEpidemics in Great Plains. Some states with >50% yield losses.

Scot Nelson
Banana Panama wilt 2

CC BY-SA 2.0
1920 - 1950sBananaPanama diseaseCentral America
South America
Gros Michel variety nearly wiped out. Led to adoption of the Cavendish variety resistant to Panama disease, but inferior in taste.
1916WheatStem rustNorth AmericaDevastating epidemic controlled by eradication of alternate host, barberry.

Downy Mildew on 'Valiant' cultivar
CC BY-SA 4.0
by David S. Jones, Patricia McManus
1878 - 1885GrapesDowny mildewFranceSpread throughout Europe with devastating impact on wine industry. Led to use of copper in Bordeaux mix, the first chemical widely used to protect plants.

CC BY-SA 2.0 by CIAT
1868CoffeeRustSri LankaWiped out coffee crop. Brits become tea drinkers.

CC BY-NC-ND 2.0 by benmillett
1840sPotatoLate blightIrelandMajor factor in Irish Potato Famine. 2.5 million people died or emigrated.