What are the damage symptoms of flower bud rot in marigold and how it can be controlled?

The fungus infects the blossom buds. The infected buds shrivel and become dark brown in colour. The pathogen also infects leaves causing blight. The infection is visible in the kind of brown necrotic spots on margins and tips of older leaves. It can be controlled by spray of Mancozeb @ 2 grams/liter of water to control effectively this disease.