Green grass turns into black orchid
During the hot summer season, orchid leaves suddenly turn black and withered like poisoning, which is often a dangerous sign of black rot outbreaks. If not treated in time, the entire plant will die in just 3-5 days. This article teaches you hands-on how to save endangered orchids through 4 first aid steps +3 preventive measures. 1. Identification of black rot symptoms 1.1 Characteristics of early grass decline When the outer leaves appear scorched and withered, but the root system still maintains more than 3 healthy crystal roots, grass decline is normal. The diseased leaves need to be pruned in time and watered by alternating wet and dry methods: delay the watering for 2 days after the surface of the plant material turns white, and mix it with a special orchid fertilizer diluted 2000 times. 1.2 Signs of severe infection If the base of the leaves is blackened, the head of the reed is soft and rotten, and it is accompanied by a stench, it means that the bacteria have invaded the growth site. At this time, the basin must be removed immediately, and the survival rate after a delay of more than 48 hours will be less than 30%. 2. First aid steps for black rot disease 2.1 Isolation and treatment of sick plants Use alcohol-disinfected scissors to remove the infected site, and the incision must be more than 2 cm away from the diseased tissue. Focus on checking the status of false bulbs. If brown spots appear, cut them lengthwise to thoroughly remove diseased cells. 2.2 The deep sterilization process is equipped with a compound liquid solution of difenoconazole (1:300)+ kasugamycin (1:800), and the treated orchid plants are soaked for 6-8 hours. Turn the plants every 2 hours to ensure that there are no dead spots in sterilization, paying special attention to the water accumulation in the leaf center. Green grass turns into black blue 2.3 The key points of plant replacement are to use high-temperature steamed pine bark mixed with volcanic rock (ratio of 3:1), and the bottom of the basin is padded with 3cm ceramsite to enhance ventilation. When putting into the pot, expose 1/3 of the reed head, and use a stepped watering method: after watering the roots for the first time, water it thoroughly at an interval of 72 hours. 3. Disease Prevention System 3.1 Environmental control skills Keep the temperature difference between day and night above 8℃, and the daytime temperature does not exceed 32℃. Use circulating fans to create air flow, but avoid blowing directly on the leaves. Turn the flowerpot 90 degrees every 10 days to allow the plants to receive even light. 3.2 The drug protection plan implements a "three-time" sterilization method every month: in the first week, mancozeb (1:1000) is used to irrigate roots, in the second week, azoxystrobin (1:1500) is sprayed, and in the third week, Bacillus subtilis biological preparation is used. Furadan particles are pre-embedded in the plant material to form a three-dimensional protective net.
By promptly identifying early symptoms, standardizing first aid operations, and establishing a prevention system, the cure rate of orchid black rot can reach more than 85%. Keep the key points in mind: treatment survival rate increases by 40% within 24 hours of onset, maintaining the humidity of the plant material within the range of 35%-45%, and regular use of biological agents can reduce the risk of recurrence by 90%.