at the later stage will turn from gray to tan or reddish brown. Mature tan lesions consist of small pustules surrounded by discolored necrotic areas. Tan spores can be found at the necrotic areas on the underside of the leaf. In the case of reddish brown lesions, there are larger reddish brown necrotic areas with few pustules and visible spores on the underside of the leaf. A good way to distinguish Asian Soybean Rust from other diseases is to look at the pustules it produces. ASR pustules usually do not have the yellow halo which is typical of bacterial pustules. 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. Soybean plants are one of ASR's most known hosts and are susceptible at any stage in the life cycle. However, symptoms are most commonly found during or after flowering. ASR infection will reduce pod production and fill. Environment 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, Taiwan, Thailand, the Philippines, Mozambique, Nigeria, Rwanda, Uganda, Zimbabwe, South Africa, Brazil, Argentina, and Paraguay. This disease was first detected in the Caribbean in Puerto Rico in 1976 and first reported in the continental United States in 2004. Asian Soybean Rust favors environments that are humid and warm. A continuous period of wetness on leaves will aid the growth of this disease since this situation is required for spores to germinate. Therefore, is most likely to appear under conditions of and a relative humidity of 75% to 80%. Therefore, ASR is a more serious problem in tropical and subtropical areas in Asia, Africa, Australia and South America. It is unable to survive the cold winters of northern habitats. However, this pathogen can be spread easily from wind and storm fronts and can inoculate quickly within a soybean field under favorable environmental conditions. Disease cycle Soybean rust is spread by windblown spores and has caused significant crop losses in many soybean-growing regions of the world. Windblown spores can travel for great distances and are released in cycles of seven days to two weeks. It is likely that ASR will survive on vast acreages of naturalized kudzu in the southern U.S. and thereby establish a permanent presence in