The U.S. ornamental plant industry, which includes deciduous and evergreen trees, shrubs, cut flowers, and foliage and flowering potted plants, grew in value to $14.3 billion in 2002. Geranium, chrysanthemum, gladiolus, and daylily are just a few of the many crops produced in the U.S.
According to Dr. James W. Buck, assistant plant pathology professor at the University of Georgia, a fungal infection called rust has the ability to negatively affect production of many ornamental crops. "Because live plants are shipped all over the country, the risk for rapid disease spread is substantial," said Buck. While rust fungi do not usually kill infected plants, infection by rusts will reduce plant health and flower production.
Currently, more than 125 species of fungi that cause rust have been reported on 56 different ornamental crops. "Rust pathogens cannot be adequately detected on contaminated but symptomless plant material entering the U.S. or moving state-to-state," said Buck. "As such, rust pathogens have the potential to dramatically affect ornamental crop production," he said.
Rust spores can easily lodge in the crown of plants that have had foliage removed for shipping purposes. Symptomless plants are then moved long distances through international or interstate trade, dispersing the pathogen and introducing it into areas that were previously pathogen-free.
While quarantine restrictions and eradication efforts are used to manage rust outbreaks and minimize potential disease loss, such efforts are not perfect and can have a significant economic impact on crop production. International trade of ornamental crops has made the exclusion of rust pathogens difficult because contaminated plant parts may
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Contact: Amy Steigman
asteigman@scisoc.org
651-994-3802
American Phytopathological Society
17-Feb-2004