[1] The virus is transmitted via Polymyxa graminis, which is a plasmodiophorid protist, through the resting spores that survive in the soil, and eventually zoospores.

Current agricultural practices have been ineffective at eliminating the virus, but breeding resistance appears to be the only way to help reduce the disease.

Other species of Hordeum have been experimentally inoculated and exhibited similar symptoms, but this has since been categorized as a different strain of disease called barley mild mosaic virus.

That being said, the signature symptom exhibited by the barley from the virus is a yellowing and mosaic flecking of the youngest leaves that often appears in the winter or early spring.

[4] Early on the plant leaves begin to show a pale green color, and over time the changes become more drastic with severe yellowing and mosaic patterns.

[5] P. graminis is a soil-borne pathogen, so it is spread by tools, water, animals, and other means of physically moving soil.

[4] Common countries to find the virus include Japan, China, Ukraine, Greece, Germany, English, Belgium, and France.

Chemical controls, crop rotation, and soil sanitation have all proven rather ineffective at combatting the virus.

A study performed in Japan yielded positive results for resistance to BaYMV when using Kashimamugi, Haruna Nijo, and Haganemugi, which are all barley cultivars.

This valuable resource has suffered tremendous losses due to the barley yellow mosaic virus.

[1] This would equate to losing 255 million dollars in one year in the UK, and even more in Japan if barley yields remain steady.