Texas AgriLife Research scientists are taking a close look at the damage caused by the wheat curl mite to determine some best management practices for producers and researchers. Jacob Price, AgriLife Research associate researcher-plant pathology, participated in a virus survey in 2008 that encompassed most of the central U.S.
In the survey, the most common wheat viruses found in the 75 million acres of wheat across the U.S. were wheat streak mosaic virus, wheat mosaic virus (formerly High Plains virus) and a fairly recently discovered one, Triticum mosaic virus.
These viruses all have one common factor: they are all vectored by the wheat curl mite. Because there are no chemicals labeled for control of the wheat curl mite, researchers must find other ways to combat it. Price says one way will be to work with wheat breeders. “Because we found Triticum at such a high prevalence, it would be wise for the breeders to work closely with the pathologists when these new diseases come in,” he says. “We can work together to develop genetic resistance for problems facing us now and those that might affect us in the future.”
Fekede Workneh, an AgriLife Research scientist in plant pathology, has been working to model the gradient of severity of wheat streak mosaic and its impact on grain yields across the field. Volunteer wheat and grass vegetation are the green bridges that allow wheat curl mites to exist through the summer until the new wheat crop starts growing. The most damage appears to occur if infestation takes place early in the fall. However research is under way to determine the impact of time of infection.
“If it is a distant source, you will see sporadic and random occurrences across the field, because the mites are carried in the wind and their population gets diluted and dispersed,” he says. “But the closer the source of mites, you will see more of a gradient virus infection in the field, beginning at the edge.”