Hope for Florida’s Declining Citrus Industry

Florida Department of Citrus recently reported citrus production in Florida could drop as much as 82 percent by 2026, but UF/IFAS researchers may have the key to prevent this devastating decline.

Florida Department of Citrus wrote,“The Florida OJ situation continues to be affected by the lower production levels resulting from the spread of Huanglongbing (HLB, Citrus Greening).”

Citrus greening was first detected in Florida in 2005.

After years of continued decline, UF/IFAS researchers have developed a new tool to battle the highly destructive greening bacterium—a greening-resistant citrus tree.

Although these trees won’t be ready for commercial use for several years, their resilience brings a fresh hope for the iconic Florida Citrus industry.

Two researchers at UF/IFAS’s Citrus Research and Education Center (CREC) were able to isolate a gene from the Aribidopsis plant, a member of the mustard family, to create the greening-resistant tree.

There is no cure for citrus greening, making resistance to the bacterium a crucial breakthrough.

Greening is carried from tree to tree by the Asian citrus psyllid. When the insect sucks on leaf sap, it leaves behind the greening bacteria, which enters the phloem and spreads throughout the tree. Greening starves the tree of nutrients, damages its roots and causes the fruit to be green and misshapen, forcing its rejection for fresh fruit sales and sometimes for juice. Most infected trees eventually die.

Two studies were conducted over the course of several years to determine resistance and viability of different genetically modified citrus trees. A transgenic line was found to thrive in greening-infected groves and could potentially be resistant to citrus canker and black spot.

Researchers will transfer this gene into additional commercial varieties commonly grown in Florida and they plan to “stack” this gene with another that provides resistance by a completely different mechanism in order to overcome greening in the field.