Which of the following diseases is caused by fungal pathogens affecting the foliage of grain sorghum?

Sooty stripe is indeed caused by a fungal pathogen and significantly impacts the foliage of grain sorghum. It is characterized by the appearance of dark streaks on the leaves which can lead to reduced photosynthesis and ultimately affect the overall health and yield of the plant. The causal organism, Phaeosphaeria sorghina, thrives in certain environmental conditions, making it essential for growers to identify and manage it effectively.

The other diseases listed may affect sorghum but either do not stem from fungal pathogens or do not primarily target the foliage. For example, bacterial streak is caused by a bacterium and primarily affects the leaves but is not related to fungal pathogens. Root rot is associated with soil-borne pathogens, including fungi, but it impacts the roots, not the foliage. Yellow blight, while a disease linked with grains, often pertains to a different type of pathogen or is sometimes used to describe various blights that may not specifically target sorghum foliage. Understanding these distinctions helps in developing accurate management strategies for grain sorghum diseases.