Back to Wheat – Educational Resources

Wheat Virus Losses

Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and Wheat mosaic virus (WMoV) are all members of a virus complex that causes devastating losses to wheat production throughout the Great Plains Region of the U.S. Early season infection typically begins as a light yellowing and light mosaic pattern in infected plants (Fig 1). These symptoms are often confused with drought or nutrient defficiency. However, as infection progresses these symptoms increase in severity to include definit streaks of yellowed tissue leading to necrosis (Fig. 2). In many cases symptoms begin on the edge of infected fields due to intital infestation of the wheat curl mite. These areas may be difficult to identify due to light symptom development (Fig 3). As the season progresses symptoms become more severe and move futher into the field typically in the direction of the praveling winds and transfer of the mite vector (Fig. 4).

Early detection is paramount to management of WSMV due to its effects on root development and reduction in plant water use efficiency. Losses to WSMV can be devastating particularly during early infections which are commonly found during early planting for dual purpose grazing/grain production and losses are increased due to the added cost of irrigation.

Fig. 1

Fig. 2

Fig. 3

Fig. 4