By Tom Spreen
The Florida citrus industry has experienced a difficult stretch of years since the record crop year of 2003–04, when over 240 million 90-pound boxes of oranges were produced.
INDUSTRY DECLINE
In 2004, multiple hurricanes crisscrossed the Florida peninsula. They were the first hurricanes to hit the citrus-producing area of Florida since Hurricane Dora in 1964. The hurricanes themselves did not cause extensive tree loss but managed to spread both citrus canker and huanglongbing (HLB or citrus greening) throughout the citrus belt. As a result, the citrus canker eradication program was abandoned on Jan. 11, 2006.
HLB did not begin to show its effect on tree productivity until the 2010–11 season, when the Florida citrus crop entered a period of contraction that was exacerbated by Hurricane Irma, which struck Southwest and Central Florida in 2017. The citrus crop continued to decline until last season when Hurricane Ian followed a path quite similar to that of Hurricane Charley, the first hurricane of 2004. The result of these calamities was a 2022–23 orange crop of 15.85 million boxes and a grapefruit crop of 1.81 million boxes, down dramatically from their peaks 20 years earlier.
The industry has also witnessed a large decline in bearing acreage. The USDA reports that bearing citrus acreage in Florida was 718,100 acres in 2002–03 and 340,200 acres in 2021–22, a decline of more than 50%. It is likely that bearing acreage has declined further in the aftermath of Hurricane Ian.
Is there a road back for Florida citrus? Continued population growth in Florida limits land availability for any agricultural enterprise, including citrus. Higher population also puts pressure on the supply of fresh water. The cost structure of the industry has increased due to the need to deal with diseases like HLB as well as higher labor and energy costs.
OTC OFFERS HOPE
But … A new compound, oxytetracycline (OTC), was approved for use in citrus in October of 2022. OTC is injected into the trunk of citrus trees. It is an antimicrobial agent that targets the bacteria that causes HLB infection. Material cost plus the cost of application runs a little over $1.00 per tree. I can personally attest that the treatment is very effective, even though it will likely be necessary to repeat the application of OTC annually.
The benefit of OTC becomes clear once one sees the condition of trees two to three weeks after application. In my own Valencia grove, I saw the greenest trees I have seen in a long time and no evidence of HLB. My grove manager is of the opinion that the OTC did not kill 100% of the HLB-causing bacteria but has suppressed the level of infection to the point that the symptoms of HLB disappeared.
The remaining questions are: How long does the benefit of OTC persist? Will it allow a Valencia tree to hold its crop until harvest? In addition, will there be a beneficial effect on juice quality, another casualty of HLB? Many groves have been struggling to produce crops with juice yields above 5 pounds solids per box.
So, it appears that there may exist a road back for Florida citrus: an attack on the HLB-causing bacteria through the use of antimicrobial agents injected directly into the tree. To be clear, this approach has its drawbacks as the tree must be retreated each year. It is also unknown if there are long-term negative effects on tree life. But a regime of the use of individual protective coverings (IPC) on newly planted trees combined with the application of antimicrobial agents such as OTC provides growers a roadmap of how to plant new acreage that will produce crops that are economically viable.
Longer term, there is still important ongoing work on the development of an HLB-resistant tree. This line of research should be continued because ultimately it offers a lower cost solution to the suppression of HLB compared to the use of IPCs on new plantings combined with the use of antimicrobials later in tree life. In the meantime, however, a road back has been discovered.
Tom Spreen is professor emeritus in the Food and Resource Economics Department of the University of Florida and senior economic consultant in the Economic and Market Research Department of the Florida Department of Citrus.