How to identify and control the white silk disease of orchids

White silk disease is a worldwide orchid disease, which mainly harms Cartland, Oncidium, Phalaenopsis, Wandai Orchid and so on. The pathogen is Sclerotiumrolfii. Because the white mycelium is seen on the surface of the soil and at the base of the stem of the orchid plant, causing the stem base to rot, it is also called basal rot. The earliest signal of plant infection is that yellow to brown disease spots appear at the base of the stem, followed by water-stained annular grooves and rot, leaves and false bulbs will also wither and rot, resulting in the death of the whole plant. In addition to cutting off the diseased stems, the whole orchid should be disinfected in 1% copper sulfate solution, and the flowerpots, culture soil and shelves should be sterilized with 2% formalin solution.