Rust (fungus) an autoecious fungus which can complete its life cycle on a single host species. Understanding the life cycles of rust fungi allows for proper disease management. There are definite patterns of relationship with host plant groups and the rust fungi that parasitize them. Some genera of rust fungi, especially "Puccinia" and "Uromyces", comprise species that are capable of parasitizing plants of many families. Other rust genera appear to be restricted to certain plant groups. Host restriction may, in heteroecious species, apply to both phases of life cycle or to only one phase. The fungi produce asexual spores which disperse by
Soybean rust Besides, ASR pustules are raised and can be commonly found on the underside of the leaf which makes it different from the lesions caused by spot diseases. As one of ASR's most known hosts, soybean plants are susceptible at any stage in the life cycle. However, symptoms are most commonly found during or after flowering. Soybean plants infected by Asian Soybean Rust will result in declining of pod production and fill. Asian Soybean Rust (ASR) was first detected in Asia. It has been found in many countries around the world since then. For example, Australia, China, Korea, India, Japan, Nepal,