Viruses of canna
Canna yellow mottle virus and canna mosaic virus can be fatal to plants if the proper control methods are not applied.
There are several viruses that cause disease on cannas, such as canna yellow mottle virus and canna mosaic virus (also known as bean yellow mosaic virus). The symptoms caused by either of these viruses can be subtle in younger plants, but may become more pronounced over time. Symptoms include mottling of the foliage, discolored streaks on foliage (particularly between the veins) and plant stunting. These diseases can certainly impact overall plant health and sales.
Photo 1. Virus symptoms are visible on the
emerging foliage of a virus-infected canna plant.
As with many other diseases, control begins with making sure that you start with healthy plant material. One common means of disease spread is via propagation from infected plant material. Be sure to take the extra time to inspect incoming plant material for symptoms of these viruses. It is also worth learning what steps your supplier has in place to minimize the incidence of these canna viruses.
Canna mosaic virus can also be spread by aphid vectors in a non-persistent manner. Aphid populations should be carefully monitored in the growing area. If canna mosaic is present, higher numbers of aphids will also lead to greater disease spread. There is no known insect vector for canna yellow mottle virus.
Virus-infected plant material cannot be treated or cured. Symptomatic material should be removed and destroyed following a diagnosis. Specific diagnosis of canna viruses generally cannot be done in the greenhouse. Please contact the MSU Diagnostic Services lab if you wish to pursue specific identification of canna viruses.