Citrus Greening Quarantines Expand in CA, TX, and LA
The USDA Animal & Plant Health Inspection Service (APHIS) has announced that it will quarantine areas in California, Texas, and Louisiana for citrus greening after positive samples were confirmed in those areas.
The expanded areas include Los Angeles, Orange, Riverside, and San Bernardino Counties in California, Kleberg, Kenedy, and Webb Counties in Texas, and Plaquemines and Saint Bernard Parishes in Louisiana.
The regulations are effective immediately and necessitate an APHIS compliance agreement to move regulated nursery stock from the quarantine areas. Growing and shipping conditions are specified. The current quarantine includes parts of California, all of Florida, all of Georgia, parts of Louisiana, all of Puerto Rico, parts of South Carolina, parts of Texas, and all of the Virgin Islands. Additional and more extensive quarantines exist for Asian citrus psyllid.
Citrus greening, also known as Huanglongbing and yellow dragon disease, is caused by a bacterium, Candidatus Liberibacter asiaticus, is the most destructive plant disease of citrus worldwide. Both adults and nymphs of Asian citrus psyllid vector the disease during foliar feeding. Once infected, the bacterium replicates and colonizes phloem tissue. Eventually, phloem tissue becomes blocked, preventing nutrients from being translocated downward from the canopy, and the tree becomes compromised and more susceptible to other stresses. Fruit are often small, misshapen, and abnormally bitter and ultimately deemed unmarketable.
Citrus greening was first detected in the U.S. in Florida in 2005 and Mexico in 2009. A single, infected tree in California was reported in 2012, the same year it was first reported in Texas. Florida’s citrus industry has been devastated by the disease, as no controls exist and all citrus are susceptible.