Evaluation of Trunk-injected Antibiotics for Huanglongbing Management in Citrus
Posted August 2025
Researchers: Lukasz Stelinski, Izabella Martinez, Erik Roldan, Kirsten Pelz- Stelinski, Lauren Diepenbrock
Contact: Lukasz Stelinski, UF/IFAS CREC stelinski@ufl.edu
Summary:
Recent studies have demonstrated that trunk-injected oxytetracycline (OTC) can effectively reduce Candidatus Liberibacter asiaticus (CLas) levels in mature citrus trees, leading to improved yield. Furthermore, OTC treatments have been shown to decrease CLas acquisition by both adult and nymph ACP, thereby disrupting pathogen transmission. However, the development of resistance to OTC necessitates exploration of alternative antimicrobial treatments to rotate with OTC. In this context, streptomycin has emerged as a potential rotational candidate for trunk injection. The objective of this investigation was to evaluate the efficacy of streptomycin with and without co-injected OTC, as an alternative treatment for remediation of HLB symptoms in commercial citrus. We monitored CLas infection in treated trees up to 300 days post-injection and quantified the effects of the treatments on pathogen acquisition, tree growth, and yield. Our results indicate that both streptomycin and OTC similarly reduce CLas abundance in trees, disrupt pathogen acquisition by ACP, and increase yield as compared with non-injected controls.
Take Home Message:
- Trunk-injected antibiotics reduce pathogen in tree phloem.
- Trunk-injected antibiotics reduce pathogen transmission by psyllids.
- Trunk-injected antibiotics increase yield.
