Most wheat varieties are resistant to this pathogen, although that can vary. Viruses typically cause stunting of plants as well as a discoloration of leaves, with the most common color either red or yellow. In some viruses, streaking of the leaves or a mosaic pattern also can be seen. Viruses are unusual pathogens, because they neither require a food source nor have the typical physiological processes associated with other biotic pathogens. Viruses are vectored to plant cells, release their genetic material, and cause the plant cell to replicate more copies of the virus.
Most viruses consist of only a genetic and a protective protein outer coat.
Once inside plant cells, the virus sheds the protein coat, and the genetic material begins replicating the virus. These varieties do not allow virus replication to occur, and the infection is stopped early. Other control measures are directed at reducing the time the plants are in the field when vectors are active, which explains the recommendation to plant after the fly-free date, when insect activity is reduced. Systemic insecticide seed treatments have also shown some success. First, rule out any other problem that may have caused the symptoms such as winterkill, nutrient imbalances, or herbicide carryover.