[4] P. tritici-repentis overwinters on stubble, and due to recent heavily no-till/residue retention cultural practices, increased incidence and yield loss of up to 49% has been witnessed if ideal conditions occur.

[6] It forms characteristic, dark, oval-shaped spots of necrotic tissue surrounded by a yellow ring.

Lesions typically appear on both upper and lower leaf surfaces, and initially are tan to brown specks.

The development of a dark brown to black spot in the center the lesion is characteristic of the disease.

[11] If warmer temperatures and moist conditions persist, spores known as conidia will move up plant as secondary inoculum and can also infect head/spikes.

Symptoms on the head are indistinct, but can cause brownish glumes, and grains can have a reddish appearance similar to the pathogen Fusarium.

[11] P. tritici-repentis survives and overwinters as pseudothecia on stubble from the previous year's infected crop.

Such ascospores produced are large and typically dispersed by wind, but do not travel far due to their size.

This means that rain, significant dew or high canopy humidity are factors that can lead to infection.

[17] There is research to suggest that plant height may also influence the amount of disease able to form due to the pathogen.

Tan spot is important enough and causing large enough yield losses to continually prompt new research.