Agropyron mosaic

Agropyron mosaic virus (AgMV) is a viral pathogen classified within the genus Potyvirus, family Potyviridae. It primarily affects perennial grasses, particularly couch grass (Elymus repens), which serves as the primary reservoir for the virus, and subsequently spreads to various cereal crops like wheat and barley.

The characteristic symptoms of this disease include mosaic patterns, chlorotic striping, and streaking on leaves. In severe cases, infected plants exhibit stunted growth, reduced tillering, and distorted spikes, which leads to a significant decrease in biomass and overall grain yield potential.

The biology of the virus is strictly dependent on its vector, the wheat curl mite Aceria tosichella. The mite acquires the virus by feeding on infected host plants and subsequently transmits it to healthy cereals. This transmission is non-persistent, meaning the mite can transmit the virus for a limited period after feeding.

Environmental conditions that favor the proliferation of the mite vector are critical for disease development. A mild autumn and extended periods of warm weather enable the migration of mites from infested weeds or early-emerged volunteer wheat to newly sown winter crops, facilitating widespread infection.

Management of Agropyron mosaic focuses on breaking the virus cycle and controlling the vector. Key strategies include:

• Elimination of reservoir hosts like couch grass in and around fields.
• Strategic timing of sowing to avoid peaks in mite activity.
• Deployment of resistant or tolerant cereal cultivars.
• Monitoring mite populations and applying acaricides when necessary to reduce viral transmission.