Sweet Orange Scab Quarantine Expands

Posted by Christina Herrick|March 28, 2011

Last week, USDA’s Animal and Plant Health Inspection Service (APHIS) revised the Federal Order for sweet orange scab (SOS) to add the entire states of Florida and Arizona to the list of quarantine areas. The revised Order also adds conditions to allow the movement of regulated fruit from the quarantine areas.

SOS is a fungal disease of citrus that results in unsightly, scab-like lesions developing on fruit rinds. Fruit is not a vector of the disease, so fruit movement should not be an issue. The pathogen can be spread long distances within infected nursery stock and other plant parts.

On Dec. 23, 2010, the APHIS Molecular Diagnostics Laboratory (MDL) confirmed SOS in Florida from a grapefruit tree in a campground in Polk County and from a bitter orange tree at a residence in Broward County. On Jan. 10, 2011, MDL confirmed SOS from a residential tangerine tree from Sarasota County. One infected tree was removed and Federal Emergency Action Notifications were issued to the remaining property owners to prevent movement of potentially infested plant material. Subsequent surveys have positively detected SOS in the following Florida Counties: Charlotte, Hillsborough, Indian River, Manatee, Orange, Palm Beach, and Pinellas.

MDL also confirmed SOS on fruit collected from a tangerine grove in Maricopa County, AZ, on Jan. 10, 2011, and from a lemon sample from Yuma County, Arizona on Feb. 23, 2011. Delimitation surveys were conducted in citrus-producing regions of Arizona and EANs were issued to positive establishments. To date, SOS has been detected in Maricopa and Yuma Counties in Arizona.

Last summer, MDL confirmed the first U.S. detection of the fungal pathogen ElsinoÃ« australis, causal agent of SOS, in Texas. SOS was detected and confirmed in Louisiana and Mississippi in August 2010 and October 2010, respectively. On Dec. 22, 2010, a Federal Order was issued to establish SOS quarantine areas for the entire States of Louisiana, Mississippi, and Texas.