Pest Profile

Spindle streak mosaic virus can cause reduced tillering and yield losses in winter wheat, especially in cool, wet soilds. The virus appears to be transmitted (“vectored”) by a soilborne fungus-like organism, Polymyxa graminis, that occurs in soils.

Wheat spindle streak mosaic causes a yellow discoloration to wheat seedlings. This yellow discoloration is often most intense in the wettest areas of a field. Leaves of infected plants have long, yellow streaks that are slightly wider in the middle than at their ends. Symptoms are similar to wheat soilborne mosaic, and plants often are infected with both diseases. Symptoms fade when higher temperatures reduce viral activity within infected plants.