Bacterial leaf spot of bougainvillea caused by Pseudomonas andropogonis in Brunei Darussalam

A leaf spot disease was found widespread on Bougainvillea in Brunei Darussalam. Leaf spots were characterized by circular to irregular brown necrotic areas with yellow haloes. A non‐fluorescent bacterium was isolated consistently from the lesions and confirmed as the causal agent by Koch's postulates. On the basis of biochemical characterization and inoculation tests, the bacterium was identified as Pseudomonas andropogonis. This is the first report of a bacterial disease on bougainvillea in Brunei Darussalam.