Citrus Greening Quarantines Expand in Texas
USDA APHIS announced that citrus greening quarantine areas in Texas will again expand after multiple positive samples were detected in those areas. APHIS added Brazoria, Galveston, and Jim Hogg Counties, all in Texas.
The regulations are effective immediately and necessitate an APHIS compliance agreement to facilitate movement of regulated nursery stock in 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 are prevented 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 US 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 is susceptible.