The water mould (oomycete) "Bremia lactucae" has infected commercial crops in Italy and California. In 2002 on the Ligurian coast, widespread infection of several cultivars, most severely 'Florabella Pink' and to a lesser extent 'Florabella Gold' and 'Florabella White', resulted in leaf blistering and the development of chlorotic lesions on the leaves, and white patches on the undersides, particularly in areas of poor ventilation. There was an outbreak of downy mildew in a cultivated crop of "Xerochrysum bracteatum" in San Mateo County, California in 2006, in which the leaves developed large chlorotic lesions. A "Phytoplasma" infection damaged "X. bracteatum" crops in the Czech Republic between 1994 and 2001, causing poor growth, bronzing of foliage, and malformation of flower heads. Genetically, the pathogen was indistinguishable from the agent of aster yellows. The root-knot nematode ("Meloidogyne incognita") attacks and forms galls on the roots, which leads to the morbidity or death of the plant.