As R.P. Singh, J. Huerta-Espino, and A.P. Roelfs say in their comprehensive review of literature on the wheat rusts for UN FAO:
Although Gadd first described stripe rust of wheat in 1777, it was not until 1896 that Eriksson and Henning showed that stripe rust resulted from a separate pathogen, which they named P. glumarum. In 1953, Hylander et al. revived the name P. striiformis.
Symptoms
Yellow rust, or stripe 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 of wheat are Triticum aestivum, Triticum turgidum, triticale, and a few Hordeum vulgare cultivars. Other cereal rust fungi have macrocyclic, heteroeciouslife cycles, involving five spore stages and two phylogenetically unrelated hosts. The alternate host of stripe rust had been unknown until 2009, when a team of scientists at the USDA-ARS Cereal Disease Lab led by Dr. Yue Jin confirmed that barberry is an alternate host. Barberry was known as an alternate host of the closely related stem rust stem rust, and for many years, when infection was observed on barberry, it was assumed to be stem rust. Scientists observed rust infection on various barberry species, and inoculated spores onto grass hosts. Kentucky Bluegrass showed infection characteristic of stripe rust. Later, infected wheat plants bearing teliospores were soaked in water and suspended over barberry species. Infection was produced, thus solving a "century-old mystery" of plant pathology. The disease usually occurs early in the growth season, when temperature ranges between ; but it may occur to a maximum of. High humidity and rainfall are favorable conditions for increasing the infection on both leaf blade and leaf sheath, even on spikes when in epidemic form. Symptoms are stunted and weakened plants, shriveled grains, fewer spikes, loss in number of grains per spike and grain weight. Losses can be 50%, but in severe situations 100% is vulnerable. Since yellow rust can occur whenever the wheat plants in green and the environmental condition conducive for the spore infection, yellow rust is a sever problem in the wheat-producing regions worldwide. Temperatures during the time of winter wheat emergence and the coldest period of the year are crucial for epidemic development in winter-habit wheat crops.
The evidence of both spatial structuring and invasion has been shown for this disease. Population genetic analyses indicate a strong regional heterogeneity in levels of recombination, with clear signatures of recombination in the Himalayan and near-Himalayan regions and a predominant clonal population structure in other regions. The existence of a high genotypic diversity, recombinant population structure, high sexual reproduction ability, and the abundance of alternate host in the Himalayan and neighboring regions suggest the region as plausible PST center of origin or at least the most closer to its centre of origin. However, further exploration may be useful from Central Asia to East Asian regions.
Disease management
Breeding resistant varieties is the most cost-effective method to control this rust. Fungicides are available but vary in availability depending on their registration restrictions by national or state governments. Development of varieties resistant to the disease is always an important objective in wheat breeding programs for crop improvement. These resistance genes, however, became ineffective due to the acquisition of virulence to that particular resistance gene rendering the variety susceptible.
