HLB-Tolerant Tree Program Progressing

Tacy Callies Florida Citrus Commission, Florida Department of Citrus, HLB Management

Photo by Ute Albrecht, University of Florida Institute of Food and Agricultural Sciences

The goal of an expedited tree propagation program is to have several million HLB-tolerant or HLB-resistant trees planted in the next several years. Greg Hodges, assistant director of the Florida Department of Agriculture’s Division of Plant Industry (DPI), said he believes that goal is attainable.

Hodges and others presented the propagation plans to the Florida Citrus Commission (FCC) on July 13. The plans center around the recent discovery that the Donaldson tree appears to be tolerant of HLB, as well as several other varieties that might be HLB tolerant or resistant.

Hodges said DPI has already accelerated initiatives “to mass produce citrus budwood varieties which appear to be avoiding decline due to disease.” In addition to the Donaldson tree, DPI is working with the citrus varieties Parson Brown, Carney 2, Carney 3 and Roble.   

Florida Department of Citrus (FDOC) Director of Scientific Research Rosa Walsh said the FDOC will use $1 million provided by the Florida Legislature to fund its part of the plan. The FDOC will enter into agreements that increase the production of HLB-tolerant trees and commercialize technologies that produce HLB tolerance or resistance in trees. The FCC, which governs the FDOC, is expected to approve the plans July 20 and enter into agreements with nursery participants and grower cooperators by late August.

U.S. Department of Agriculture (USDA) post-doctoral associate Matt Mattia told the FCC that he discovered a single Donaldson tree at USDA’s A.H. Whitmore Foundation Farm in July 2021. Old records indicated the tree was planted on Swingle rootstock. The first recorded mention of a Donaldson tree was in 1943 at the Hiawassee Farm in Orlando. The first record of a Donaldson tree at the A.H. Whitmore Foundation Farm was in 1978, Mattia said.

In March, FCC Chairman Steve Johnson called the Donaldson tree “a beacon of hope.” Learn more about the Donaldson tree here.

About the Author

Ernie Neff

Senior Correspondent at Large