Bacterial black spot caused byBurkholderia andropogonisonOdontoglossumand intergeneric hybrid orchids.

A new bacterial black spot disease was observed onOdontoglossum,Odontioda,Odontocidium, andVuylstekearaorchids in Japan. Typical symptoms on the leaves were dark or black spots (or both) with a yellow halo. The causal agent was identified asBurkholderia andropogonis(Smith 1911) Gillis, Van Van, Bardin, Goor, Hebbar, Willems, Segers, Kersters, Heulin and Fernandez 1995. The isolates were pathogenic on four original host orchids,Phalaenopsisorchid, and tulip; they were not pathogenic on white clover or corn after needle stab inoculation. An antibiotic bactericide (oxytetracycline/streptomycin mixture WP) was most effective for controlling the disease. [ABSTRACT FROM AUTHOR]