Trunk Injection Considerations

Ernie NeffCEU, Research


A presentation titled “Trunk Injection: Difficulties and Considerations” is one of the first from the cancelled 2020 Florida Citrus Growers’ Institute to become available online. The annual event was cancelled because of COVID-19. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is working to make additional presentations that were intended for the Florida Citrus Growers’ Institute available to growers.

UF/IFAS plant physiologist Ute Albrecht with the Southwest Florida Research and Education Center in Immokalee prepared the trunk injection presentation.

“Trunk injection is a targeted application of pesticides, plant resistance activators, fertilizers or other materials in the stem or trunk … as an alternative to spraying or soil drenching,” Albrecht wrote. She pointed out that injection occurs into the xylem, adding that Candidatus Liberibacter asiaticus, the causal agent of HLB, resides in the phloem.

Advantages of trunk injection cited by Albrecht include precise delivery of materials, elimination of spray drift, reduced risk of worker exposure, reduced risk for non-target organisms, reduced pesticide load into the environment, and lengthening of time that materials are biologically active.

Trunk injection can be used to inject materials dealing with a wide array of insects as well as nematodes, fungi, bacteria and phytoplasmas.

Most trunk injections are drill-based and a few are needle-based, according to Albrecht. Needle-based injections into smaller holes pose less risk of permanent damage to the sap wood and offer more targeted application to the active zone of transport, she reported.

Concerns regarding trunk injections of any type include the time, labor and cost of injection; wounding of trees; and the impact on long-term tree vitality. Albrecht added that phytotoxicity may occur, and one-time injections won’t prevent recurrent insect colonization and pathogen infection.

See Albrecht’s full video presentation, which includes much more detailed information. A PDF of the presentation is also online.

Restricted use pesticide license and Certified Crop Advisor continuing education units (CEUs) are available to those viewing the Florida Citrus Growers’ Institute presentations. Get CEUs here.

About the Author

Ernie Neff

Senior Correspondent at Large