The disease is caused by the fungus Tilletia indica Mitra, also known as Neovossia indica. This disease is influenced by weather and climatic conditions. The disease was discovered in 1931 in the city of Karnal in northern India. The disease has been found in Pakistan, Afghanistan, Iran, Mexico, Nepal, Syria, and a few places in the United States.
Karnal bunt has minimal effect on quality and yield of wheat.
The disease is managed by use of clean seed treated with fungicides and appropriate agricultural practices. The seed infected with Karnal bunt has been planted all over India. However, Karnal bunt has not spread throughout the whole country and is well localized. The disease cannot establish in new locations where climatic conditions are not favorable. The processing of grain used for consumption often kills Tilletia indica , and grain used for consumption is not a risk for the spread of this disease.