How to Prevent and Treat Common Diseases of Chrysanthemums
As a traditional famous flower in China, chrysanthemums often encounter various diseases during cultivation. Mastering scientific prevention and treatment methods not only ensures the healthy growth of the plants but also improves the quality of the flowers. This article will provide a detailed analysis from symptom identification to systematic prevention and treatment for the four most common diseases: black spot disease, powdery mildew, and others.
Chrysanthemum Black Spot Disease Prevention System
Characteristics of Black Spot Disease Symptoms
Typical symptoms include the appearance of circular blackish-brown spots 2-10mm in diameter on the leaf surface, with radiating edges. In high humidity, the lesions expand rapidly, causing the leaves to turn yellow and fall off.
Systemic Prevention and Treatment Plan
1. Remove infected leaves immediately and incinerate them in a centralized manner. 2. Implement a 3-year crop rotation system (open-field cultivation) or change the potting soil annually. 3. Spray 50% carbendazim 500 times liquid for soil disinfection after pruning in winter. 4. Spray mancozeb preventively before the rainy season.
Comprehensive Prevention and Treatment of Chrysanthemum Powdery Mildew
Key Points for Identifying Powdery Mildew
Initially, a white powdery mold layer appears on the leaf surface, gradually covering the entire leaf. In severe cases, it causes the leaves to curl and deform, and the development of flower buds is hindered.
Environmental Control Measures
1. Maintain a spacing of more than 40cm between plants to ensure ventilation. 2. Use drip irrigation technology to control air humidity below 65%. 3. Spray 25% pyraclostrobin suspension 2000 times liquid at the early stage of the disease. 4. Apply more phosphorus and potassium fertilizers to improve disease resistance.
Full Management of Chrysanthemum Stem Rot Disease
Characteristics of the Disease Stage
Young seedlings show water-soaked brown spots at the base, while mature plants suddenly wilt. This disease is highly contagious and has a high fatality rate.
How to Prevent and Treat Common Diseases of Chrysanthemums
Key Control Techniques
1. Use disinfected substrates for seedlings to avoid wound infection. 2. Control the amount of nitrogen fertilizer and apply calcium and magnesium trace elements. 3. Remove standing water promptly after rain to keep the root zone dry. 4. Irrigate with metalaxyl 3000 times liquid at the early stage of the disease.
Systemic Prevention and Control of Chrysanthemum Mosaic Disease
Virus Disease Identification and Diagnosis
Typical symptoms include yellow and green mottling on the leaves, accompanied by irregular necrotic spots. It can be transmitted by piercing-sucking insects such as aphids.
Comprehensive Control Strategy
1. Establish a virus-free mother plant garden and treat propagation materials with 55°C hot water for 10 minutes. 2. Regularly spray imidacloprid to control vectors of the virus. 3. Thoroughly disinfect tools with 75% alcohol. 4. Set a 3-meter isolation zone around infected plants.
By establishing a plant protection system focused on prevention and comprehensive treatment, combined with scientific water and fertilizer management, the disease resistance of chrysanthemums can be significantly improved. It is recommended to conduct systematic inspections monthly, take timely measures when early symptoms are detected, and pay attention to the rotation of different pesticides to avoid resistance development.