Wheat leaf rust Wheat leaf rust Wheat leaf rust is a fungal disease that affects wheat, barley and rye stems, leaves and grains. In temperate zones it is destructive on winter wheat because the pathogen overwinters. Infections can lead up to 20% yield loss, which is exacerbated by dying leaves, which fertilize the fungus. The pathogen is "Puccinia" rust fungus. "Puccinia triticina" causes "black rust", "P. recondita" causes "brown rust", and "P. striiformis" causes "yellow rust". It is the most prevalent of all the wheat rust diseases, occurring in most wheat growing regions. It causes serious epidemics in North America, Mexico and South
Stem rust healthy crop about three weeks before harvest into a black tangle of broken stems and shriveled grains by harvest. Stem rust of cereals causes yield losses in several ways: Stem rust on wheat is characterized by the presence of uredinia on the plant, which are brick-red, elongated, blister-like pustules that are easily shaken off. They most frequently occur on the leaf sheaths, but are also found on stems, leaves, glumes and awns. On leaves they develop mostly on the underside but may penetrate to the upperside. On leaf sheaths and glumes pustules rupture the epidermis, giving a ragged appearance. Towards