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
Wheat yellow rust In 1953, Hylander et al. (1953) revived the name P. striiformis. "Yellow rust" takes its name from the appearance of yellow-colored stripes produced parallel along the venations of each leaf blade. These yellow stripes are actually characteristic of uredinia that produce yellow colored urediniospores. Primary hosts of yellow rust are "Triticum aestivum" (bread wheat), "Triticum turgidum" (durum wheat), triticale, and a few "Hordeum vulgare" (barley) cultivars. The alternate host was discovered by accident in 2010. Species of common barberry plants (the alternate host of wheat stem rust) were found harbouring stripe rust. When transferred to grass hosts, Kentucky Bluegrass was