Symptoms and Control Methods of Orchid Witches' Broom Disease

OrchidWitches' broom disease has not yet been reported in China or abroad. It was first discovered in 1994 at the Wutong Mountain Nursery General Farm in Shenzhen. The early symptoms of the disease are leaf shrinkage, which mostly starts from the leaf tip; the leaves become hard and brittle and shrink in size, and many small protrusions grow on the upper middle part of the leaf, giving a rough feeling when touched. Later, when tillering occurs, the tiller buds are often relatively large at first, and then several small buds appear around the large bud. These buds do not grow roots and do not form separate plants, and black spots often appear on the leaves at the top of the tiller buds, and the plant is often dwarfed. Mostly relatively short and small varieties are susceptible to this disease. Its pathogen may be mycoplasma-like organisms (MLO), but further in-depth research is still needed. (Liu Zhongjian)