On September 5, 2008, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) confirmed gladiolus rust (GR) on samples of gladiolus leaves collected by the California Department of Food and Agriculture (CDFA) at a residence in San Bruno, San Mateo County, California.
CDFA and APHIS conducted surveys of the area around the detection site from September 15 to 29, 2008. This survey activity revealed many more residential sites with GR infection. In response to these detections, APHIS' National Program Manager for GR commenced conference calls with Regional and field staff to discuss the situation and provided technical support for mitigation and eradication of the rust following the National GR Management Plan for Exclusion and Eradication. GR is a quarantine pest for the United States. This fungus primarily attacks hybrid cultivars of gladiolus grown for flower production and could have a significant impact if it became established or was transported into greenhouses or nurseries.
Gladiolus rust is caused by the fungus Uromyces transversalis which is named for the transverse sori that develop across the width of the leaves, as compared to most rusts on monocots whose sori develop longitudinally along the veins of the leaf.
Under IPPC Standards, Uromyces transversalis (Thum.) is considered to be a pest that is transient: actionable and under eradication in the United States.