Citrus canker has been detected in New Orleans by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, Plant Protection and Quarantine division, according to LSU AgCenter plant scientist Raj Singh.

“The disease was first detected in Florida in 1910, and after its initial detection, the disease was declared eradicated twice – in 1933 and 1994,” Singh said. Citrus canker was again detected for a third time in Florida in 1995.

Louisiana has become the second state after Florida where the disease is positively identified.

“It is a serious disease of citrus because it causes defoliation, premature fruit drop, blemished fruits and tree decline, and ultimately, the infected tree stops producing fruit,” Singh said.

Citrus canker is a bacterial disease thought to have originated in southeastern Asia.

“Different strains are known to occur in citrus-growing regions of the world,” he said. “But the Asiatic strain is considered to be the most severe and widespread form of citrus canker.”

All commercially grown citrus varieties, including grapefruits, lemons, limes, oranges, sour oranges and tangerines, are susceptible to this disease.

The pathogen can cause symptoms on all young, above-ground plant parts. Symptoms on leaves start as tiny raised blisters that may enlarge and become tan to brown as the disease develops.