New Citrus Greening Treatment Product Gets Green Light from EPA

After well more than a decade of dedicated research, a potential solution for citrus greening (aka, HLB) has finally made it to the finish line. The U.S. EPA has granted unconditional registration to a novel therapy based on a naturally occurring antimicrobial peptides from spinach — known as defensins — that can protect trees against the devastating disease.

The game-changing accomplishment was a team effort led by scientists from Texas A&M and the University of Florida, among others. The new product, registered by Maryland-based Silvec Biologics Inc., relies on the comprehensive research. The EPA registration is issued under the Federal Insecticide, Fungicide and Rodenticide Act and allows the spinach defensin-based therapy product to be sold commercially without a tolerance limit.

This is huge news for the citrus industry, especially in Florida, which has struggled mightily with HLB. It has been a long, winding road for this particular solution. Indeed.

So, how did we get here? Early studies supported by Texas A&M AgriLife Research, the Foundation for Food and Agricultural Research, and Southern Gardens Citrus – a subsidiary of U.S. Sugar – laid the groundwork for advanced testing, peptide screening, and field trials.

“The technology uses a naturally non-transmissible strain of CTV (citrus tristeza virus) already common in Florida citrus trees, reprogrammed to prompt the trees to produce the spinach-derived defensin peptide therapy,” says Mike Irey, Director of Research at Southern Gardens Citrus, in Clewiston, FL

The CTV technology, pioneered by Bill Dawson, UF/IFAS Emeritus Professor, and his team at the Citrus Research and Education Center, is a therapy delivery approach that does not alter the tree’s genome. It functions like an immunization for citrus trees. A small piece of plant material from a specially developed source tree is grafted onto an existing citrus tree. This introduces a benign CTV that carries the spinach defensin peptide. Once established in the tree, the CTV continues producing the defensin peptide, which helps fight the bacteria associated with citrus greening disease.

The combined research efforts resulted in patents of the defensin by Texas A&M and the CTV technology by the University of Florida. Patent rights to both technologies are licensed to Southern Gardens Citrus, which championed the technology through sponsored research and development leading up to the EPA registration. Patent rights were sublicensed to Silvec to obtain EPA registration, commercialize the treatment and bring it to market.

“We are excited to build on 15 years of pioneering work by Southern Gardens Citrus, the University of Florida, and Texas A&M, and we look forward to beginning to partner with growers in late 2026 through the Florida CRAFT (Citrus Research and Field Trial) program,” adds Rafael Simon, Co-founder and CEO of Silvec.

Industry Reactions

News of the product approval has the citrus industry abuzz.

Matt Joyner, Executive VP and CEO of Florida Citrus Mutual, issued the following statement regarding the product registration: “A new tool is now available to strengthen citrus tree health and support the future of Florida’s citrus industry, thanks to administrator Lee Zeldin and the U.S. Environmental Protection Agency’s approval of a first-of-its-kind innovative technology for delivering treatments and therapies. We are encouraged by the growing options available to help citrus growers mitigate the effects of citrus greening and advance the industry’s recovery and renewal efforts.”

Dale Murden, President of Texas Citrus Mutual, says: “The progress Dr. [Kranthi] Mandadi and collaborators have made makes me hopeful for the future of our citrus industry. We will have new, sustainable treatments that could keep citrus trees productive under disease pressure. They aren’t just answering research questions but are developing field products to support growers so we can farm profitably.”

According to Silvec, citrus growers, starting in Florida, are expected to gain access to the product beginning in late 2026.

For more information about the new citrus greening treatment product, visit Silvec.com.