Thanatephorus cucumeris

The pathogen is known to prefer warm, wet weather, and outbreaks typically occur in the early summer months. Most symptoms of the pathogen do not occur until late summer, thus most farmers do not become aware of the diseased crop until harvest. A combination of environmental factors has been linked to the prevalence of the pathogen, such as presence of host plant, frequent rainfall/irrigation, and increased temperatures in spring and summer. In addition, a reduction of drainage of the soil due to various techniques such as soil compaction are also known to create favorable environments for the pathogen. The pathogen is dispersed as sclerotia, and these sclerotia can travel by means of wind, water, or soil movement between host plants.