Impact of fusiform rust on southern forest resources takes several forms. Seedlings are killed within 3 to 4 years, with losses in some nurseries exceeding 80 percent. Infections that occur on the main stem during the first 5 years normally result in death. Infections that occur after 5 years weaken the stem, resulting in wind breakage at the canker. Older infected trees are also lost as a result of the development of open cankers, which provide openings for wood decay fungi and insects.
Losses also occur in the form of reduced growth.
A life cycle takes approximately 2 years to complete. Black, white, water, willow, laurel, black-jack, southern red and turkey oaks are affected but not seriously damaged. The most diagnostic symptom produced by infected pines of Southern Fusiform Rust is the formation of perennial fusiform or spindle-shaped swellings on branches and main stems. Symptoms on oaks are relatively inconspicuous and require close examination of the lower leaf surfaces to observe yellow uredial pustules and black hair-like clusters of telia. The first indication of infection on needles appears as purple spots 4 to 10 weeks after inoculation.