Abstract
The effects of scattered light and the presence of contaminating fluorophores on the sensitivity and accuracy of the pyrone fluorimetric assay for indole-3-acetic acid (IAA) were investigated. With extracts from plant tissues sources of ambiguity in the fluorescence measurements were established. Criteria, based on the fluorescence spectra and kinetics of change of fluorescence intensity of the pyrone derivative, are presented for assessing the accuracy of IAA estimations using this technique.