Trunk Injection of a Curry Leaf Extract to Promote Citrus Tree Health in Huanglongbing-Endemic Regions

We developed a Murraya koenigii (curry) leaf extract and evaluated its use as a citrus tree-health supportive input by trunk injection for citrus under field-relevant biotic and abiotic stresses in Florida, where there is heavy pressure from the vector-borne disease huanglongbing, also known as citrus greening disease. In greenhouse and juvenile-tree field observations, citrus tree trunk injection with higher curry leaf extract concentrations was associated with increased canopy vigor, higher chlorophyll index, and favorable leaf-appearance ratings over time. We report qPCR measurements as exploratory research metrics only and not as a pesticidal claim. These findings justify further study of curry leaf and similar plant-derived preparations to support citrus tree physiology in challenging commercial production environments.