Which of the following diseases is characterized by dark spots on rose leaves?

The disease characterized by dark spots on rose leaves is known as Black Spot. It is primarily caused by the fungal pathogen Diplocarpon rosae, which thrives in warm, humid environments. The dark spots associated with Black Spot disease typically appear on the upper surface of the leaves, and they often have fringed edges. As the disease progresses, these spots can cause leaf yellowing and premature leaf drop, which can significantly affect the overall health of the rose plant.

In contrast, while Rust and Leaf Spot diseases can also cause discoloration on leaves, their symptoms typically differ from those of Black Spot. Rust is characterized by rust-colored pustules, particularly on the undersides of the leaves, while Leaf Spot encompasses various conditions that can cause both dark and light spots, but it does not specifically refer to the distinctive dark spots of Black Spot. Fungal Blight is a broader term that references various fungal diseases which may affect the plant's health but do not specifically describe the classic symptoms of Black Spot seen on rose leaves.