Skillfully prevent white silk disease of orchids

The white silk disease of orchid is caused by subphylum fungi. The infection began from April to May, and the disease occurred rapidly during the peak period from June to August, resulting in the rot and death of the injured orchid plants. The prevention and control measures are as follows: 1. Planting: orchids should be planted in new soil without bacteria, and formaldehyde solution should be used to disinfect the soil when using old soil; 1 / 10 plant ash should be mixed in the soil and new high-fat film should be added to prevent the soil from being slightly acidic. Selecting high-quality varieties and spraying soil surface with new high-fat film after planting can protect soil moisture, prevent evaporation, prevent sun and drought, prevent soil layer from hardening, suffocate and isolate the source of diseases and insect pests, and protect the growth of seedlings. 2. Management: maintain a ventilated and transparent growth environment and shade in summer and autumn. Pay attention to rational watering and fertilization, and spray new high-fat film to preserve soil moisture and fertilizer. Timely cut off dry and withered branches, diseased and weak branches, cross branches, over-dense branches, and remove excess buds. Apply callus antiseptic film on the pruning wound to protect the growth of wound healing tissue and prevent the infection of rot bacteria. Spraying Zhuangtiling on the buds can make the buds strong, the petals enlarged, the flowers colorful, the fragrance rich, and the florescence prolonged. 3. Chemical control: in the disease-prone season, 70% methyl topiramate wettable powder (or 75% chlorothalonil wettable powder) plus new high-fat film can be used and sprayed on the basin or leaf base, once every other week, for 3 times in a row.