Leaf streaks are usually a light green to yellow discontinuous formation. The discontinuous streaks run parallel to the leaf veins and taper to form a chlorotic spindle. The virus is transmitted by a fungus. The virus is typically a problem after long periods of wet, cool soils. Both spindle streak mosaic and soil-borne mosaic are most common in fields planted to wheat for two or more years.
Crop rotation is an effective control method.
Barley yellow dwarf virus is probably the most widely distributed virus in wheat. The symptoms are somewhat ambiguous and are often overlooked as a nutritional problem or frost damage. Usually the discoloration is characterized by various shades of yellow or reddening from the tips to the base and from margin to the midribs. Severe infection usually causes some stunting and reduction in numbers of seeds per head. BYDV is transmitted by a host of aphid species.