by Emily Hayes, Sustainable Plant Systems major
In the past several years, a virus infecting citrus crops has become increasingly hazardous to food security and plant health in the United States. The virus has largely impacted other countries previously, but did not spread to the US until recently. According to Bar-Joseph et al. it is a very difficult virus to manage.
The virus is known as the tristeza virus (CTV) and is vectored by aphids. It has been the cause of millions of citrus trees to decline in health and die and is one of the most significant citrus diseases in recent years. It appears to be mostly a problem exacerbated by man because of the introduction of new varieties into citrus fields (and use of sour orange rootstock in cultivation). The virus is not transmitted by seeds but can be spread by infected trees (grafts) shipped from Asia. Like most viral plant diseases, infected plants can be asymptomatic or produce symptoms of other plant health problems.
Florida grown citrus plants have taken a huge hit from CTV. Because of Florida’s climate, oranges tend to grow juicier compared to climates like California and thus a significant portion of orange juice production is in Florida. CTV has impacted the citrus growing industry greatly in Florida and other parts of the world. The types of citrus most susceptible to the decline strain are sweet oranges grown on a sour-orange rootstock. The virus is so devastating because it can cause stem splitting in citrus trees that are not grafted on sour-orange rootstock. It spreads very rapidly and the introduction of a certain species of aphid in the mid 90’s was the start of the epidemic that is now affecting the citrus production in Florida.
M. Bar-Joseph, R. Marcus, R. Lee. 1989. The Continuous Challenge of Citrus Tristeza Virus Control. Annual Review of Phytopathology 27: 291-316
My name is Emily Hayes. I am a senior at The Ohio State University majoring in Sustainable Plant Systems with a specialty in Horticulture and minoring in Soil Science. I currently work at The Chadwick Arboretum, located on OSU’s campus.