What are the damage symptoms of Damping Off in marigold and how it can be controlled?

The disease is most prevalent in the seedling phase. Necrotic spots and rings develop on the young seedlings causing a collapse of the seedlings. A considerable loss is sustained if seedlings are not properly cared for. It can be controlled by Soil sterilization by Formalin @ 2% before sowing the seeds and spraying of Dithane Z-78 @ 2 grams/liter of water are effective in controlling this disease.