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
On the Soul On the Soul On the Soul (Greek , "Peri Psychēs"; Latin "De Anima") is a major treatise written by Aristotle c. 350 BC. Although its topic is the soul, it is not about spirituality but rather a work in what might best be described as biopsychology, a description of the subject of psychology within a biological framework. His discussion centres on the kinds of souls possessed by different kinds of living things, distinguished by their different operations. Thus plants have the capacity for nourishment and reproduction, the minimum that must be possessed by any kind of living organism. Lower animals