Did you know? We do insect identification and rescue!

Send photos to our Director of Gardens, Amy Graham at agraham@longuevue.com to get an identification or drop off unwanted specimens at the Gate House.

Confronting Citrus Canker

Citrus canker is a common disease in New Orleans gardens, caused by the bacterium Xanthomonas axonopodis. The illness appears as lesions on fruits, leaves, and stems, causing defoliation. It causes early fruit drop, fruit reduction, and sometimes a total cessation of fruit production. Canker’s favorite trees to invade are grapefruit, lime, orange, and lemon, with kumquats being the least susceptible.

Canker was discovered 1910 in Florida and quickly expanded to seven Atlantic and Gulf Coast states, including Louisiana, by 1914. Since 1940, the pathogen seemed to have been vanquished from Louisiana – until it reappeared on June 28, 2013.

Canker enters plants through wounds or stomata. It spreads through wind transmission, splashing rain, hurricanes, landscape equipment, transport of infected citrus, and even on people’s clothing and hands. Because canker is not curable, infested fruit should be composted on site and damaged trees should eventually be removed.

Strategies to reduce canker spread:

• Manage citrus trees when leaves are dry; wet foliage increases spreading.
• In citrus orchards of any size, decontaminate hands and arms before going to new trees by washing 20 seconds with soap and hot water to remove bacteria from the skin.
• Following care or harvesting of infected trees, change and wash all clothing before handling new trees.
• Regularly clean all tools with soap and water.