The black tree disease also known as black root Is a virus which is spreading through the sprouts and plans The sprouts where the first one to encounter the plants were later on infected The sprouts are glowing small white particles floating around the air Sprouts A infected plant leaf would look like with black around the leaf The cause of the virus is unknown most ponies think it was twilight who caused the virus to spread but yet she is not guilty Why does it called the black tree disease