The presence of aster yellows was confirmed in a hard red spring wheat nursery in northwest Minnesota. Aster yellows has been known to cause economic losses in carrots and canola but this is the first time the disease has been confirmed in wheat in Minnesota. Dr. Hala Toubia Rahme suspected the presence of the disease last year.

The symptoms of aster yellows in wheat are not very clearly defined, but include purpling of the flag leaf and stunting of the plants. The disease is caused by a pathogen called a phytoplasma (formerly mycoplasmalike organism), which is similar to a bacterium.   The phytoplasma is vectored by aster leaf hopper  (Macrosteles fascifrons). There is currently no rescue treatment for aster yellows in wheat. The insect vector is very mobile and omnipresent such that control of the vector in wheat is not recommended.