A serious disease of roses is ?

• A. Fire blight
• B. Twig blight
• C. Black spot
• D. Canker stain

Answer: (C)

Black spot is a common and serious fungal disease of roses. It shows up as small, round black spots on the leaves (often with yellow margins) and soon leads to yellowing and premature leaf drop. Losing leaves hits the plant’s ability to photosynthesize, which weakens the shrub and reduces flowering and vigor. The disease loves moisture, humid air, and crowded plantings, so roses in wet, crowded beds often show heavy symptoms.

Understanding why this is considered serious helps you see why management focuses on reducing leaf wetness and removing sources of infection. Clean up and dispose of fallen leaves to remove the fungal resting spores, improve air circulation with pruning, water at the base to keep foliage dry, and use appropriate fungicides when conditions favor spread. The other diseases listed can occur on roses too, but black spot is the one most widespread and consistently damaging in typical rose plantings, making it the best-known serious rose disease.