Needle-Assisted Trunk Infusion for Trees

Tacy Callies HLB Management

Ozgur Batuman

With the devastating impacts of HLB on the citrus industry, growers are seeking alternative solutions to reduce Candidatus Liberibacter asiaticus (the bacteria that causes HLB) levels in trees and prevent disease-induced decline.

Researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are developing an automated method for delivering therapeutic liquid materials into the vascular tissue of citrus trees. 

Ozgur Batuman discussed this topic during a Sept. 15 virtual citrus seminar hosted by the UF/IFAS Southwest Florida Research and Education Center. Batuman, an assistant professor of plant pathology, shared details with growers about the ongoing research project.

According to Batuman, the mode of delivery is the largest obstacle in using HLB therapeutic materials successfully. One of the most common applications of bactericides is foliar spray. Although foliar application is an easy and economical method, it’s not very effective at controlling HLB because bactericides are not directly delivered into the citrus vascular system.

“The wax layer in the epicuticular portion of the leaf surface is not allowing most of the chemicals to be taken up by the citrus leaves and transported into the intended area,” Batuman said.

Initial UF/IFAS research experiments determined that needle-assisted trunk infusion (NATI) was the best potential delivery method.

Batuman said if the NATI delivery method can be automated, growers could treat a large number of trees quickly. With this method, a robotic arm with several modules at the end of the arm could be installed on an all-terrain vehicle or tractor. One module with needles would grip and puncture the trunk. A second module would wrap a reservoir, such as a funnel or plastic balloon, that would hold the liquid containing the bactericide. The third module would fill the reservoir.

In addition to treating the targeted disease, automated delivery could aid disease prevention through the application of prophylactic chemicals. Batuman noted that NATI has proven to be a viable method for delivering liquid materials into the citrus vasculature without causing any detrimental effect to the tree.

Ashley Robinson, AgNet Media communications intern, wrote this article.