Gentisic acid concentration in healthy and greening infected fruit albedo and leaves of citrus species and cultivars

Gentisic acid was shown to be present in citrus leaves and fruit albedo irrespective of tolerance or susceptibility of different cultivars and species to greening disease. There was no linearity between gentisic acid concentration and observed tolerance or susceptibility. An important result of this investigation was that the gentisic acid concentration increased significantly in leaves and fruit albedo of some species and cultivars as greening symptoms developed. Gentisic acid can, therefore, not be used as a reliable marker for greening tolerance or susceptibility.