Trunk injection of a curry leaf extract to promote citrus tree health in Huanglongbing-endemic regions

We developed a <i>Murraya koenigii</i> (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 stress in Florida, where there is heavy pressure from the vector borne-disease, Huanglongbing (HLB), also known as citrus greening disease. In greenhouse and juvenile-tree field observations, citrus tree trunk injection with higher curry leaf extract concentrations were 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.