Albugo occidentalis Albugo occidentalis Albugo occidentalis, the causal agent of Spinach White Rust, is an oomycete plant pathogen, although some discussions still treat it as a fungal organism. "Albugo occidentalis" is one of the most important spinach diseases in North America, found throughout the United States east of the rocky mountains. The economically important host of "Albugo occidentalis" is spinach (Spinacia oleracea); although the oomycete has also been reported to affect plants of the genus Chenopodium, the genus including the crop plant quinoa. This pathogen causes white rust or white blister of spinach. It is unrelated to the basidiomycete rusts biologically, but
White rust (disease) White rust (disease) White rust is a disease in plants caused by the oomycete "Albugo candida" or one of its close relatives. Plants susceptible to this disease generally include members of the Brassica family. White rust has been known to cause agricultural losses in fields cultivating members of this family including broccoli, cauliflower, and Indian mustard. Despite the name, it is not considered true rusts. Signs and symptoms of infection include chlorosis on leaf surfaces, white blister-like growths on the underside of leaves and on the stems of the plant, and swelling of the roots. In addition, abnormalities in the