What are the symptoms and characteristics of flower soot disease?

Soot disease, also known as sooty blotch, leaf mold, oil spot disease, oil spot disease, etc. Caused by a variety of epiphytic and parasitic bacteria that infect plants. Smoke-polluted bacteria grow on the stems, leaves or fruits of plants by forming a thin film or hard shell and growing black hyphae on the surface. The appearance is some spots. In severe cases, it looks like a layer of bituminous coal attached to the leaves, so it is called soot disease. Bituminous coal disease mainly occurs in Rosaceae, camellia, plum blossom and other flowers.

Main symptoms: Because the same plant can be infected with many kinds of germs, its symptoms are slightly different, but the black mold layer or black coal powder layer is an important feature of the disease. Sooty blotch mainly harms the leaves and branches of Lagerstroemia indica. The disease first infects the front of the leaf along the main vein, and then gradually covers the whole leaf surface. In severe cases, the surface, branches and even petioles of leaves will be covered with black coal powder, which will block the pores of leaves and hinder normal photosynthesis. Black coal dust caused by pathogenic bacteria is first produced along the main vein on the front of the leaf, and then gradually covers the whole leaf surface, which is easy to peel off. Mycelium is born on the surface of plants, black, with attached branches, extending into the epidermal cells of the host, and having haustorium to absorb nutrients. At first, a round black mildew spot was formed on the front of the leaf, and later it spread to the whole leaf, so the bacteria were not easy to fall off.