Powdery mildew
Golovinomyces cichoracearum
What is Powdery mildew (Golovinomyces cichoracearum)?
Powdery mildew, caused by the fungus Golovinomyces cichoracearum, is a widespread fungal disease affecting various plants worldwide. This fungal pathogen thrives in moderate temperatures and can infect ornamental plants like roses and dahlias, as well as vegetable crops such as cucumbers, melons, pumpkins, squash, tomatoes, and some fruits including apple pears, etc. Symptoms include irregular brown spots and blotches on the leaves of affected plants, needle browning and death in yew trees.
How does Powdery mildew (Golovinomyces cichoracearum) occur?
It reproduces asexually through the production of airborne spores. These conidia are produced on specialized structures known as conidiophores, which enable the fungus to spread. Once released, the conidia are carried to nearby susceptible plants by wind or other means. Under favorable conditions, the conidia germinate and penetrate the plant's cells, initiating infection. The fungus grows Inside the host, forming a visible mycelium, and producing more conidiophores and conidia. This reproductive cycle enables pathogens to rapidly propagate and infect new plants, necessitating effective management strategies.
Symptoms
1 - Plants Health
• Powdery fungal growth restricts sunlight, hampers photosynthesis, nutrient absorption and reduces plant energy production. Severe infections result in stunted growth, distorted leaves, and diminished vigor. • Powdery mildew can significantly decrease crop yield and affect the quality of harvested produce.
2 - Environmental Consiquences
• Airborne spores spread powdery mildew over long distances, increasing the risk of infection for nearby susceptible plants. • Powdery mildew serves as a source of inoculum, leading to widespread infections and elevated environmental disease pressure.
3 - Impact on Soil
• Severe powdery mildew infections disrupt nutrient uptake, causing imbalances in soil fertility. • Infected plant residues decompose slowly, affecting the soil's natural recycling of organic matter. • Weakened plants are more vulnerable to soilborne pathogens, impacting soil health and ecosystem balance.
Solutions
1 - Cultural Practices and Plant Selection
• Choose resistant or tolerant plant varieties. • Maintain proper spacing for good air circulation. • Avoid overhead irrigation and water at the base of plants. • Prune infected plant parts to improve airflow and reduce spread. • Enhance sunlight exposure by trimming nearby trees or shrubs.
2 - Organic Treatment
Organic alternatives for controlling powdery mildew caused by Golovinomyces cichoracearum include neem oil, baking soda solution, milk sprays, potassium bicarbonate,
3 - Biological Control
Certain biofungicides containing beneficial microorganisms, such as Bacillus subtilis, can help suppress powdery mildew and provide natural control.
4 - Fungicidal Treatments
• Some fungicides include Cyflufenamid (Torino), Quinoxyfen (Quintec), Triflumizole (Procure 480SC), Myclobutanil (Rally 40WSP), Fluopyram/Trifloxystrobin (Luna Sensation), and Pyraclostrobin/Boscalid (Pristine). • These fungicides have different modes of action, including phenyl-acetamide, quinoline, demethylation inhibitor, succinate dehydrogenase inhibitor, and quinone outside inhibitor. • Each fungicide may have specific application limits or requirements. Please note that proper usage instructions, application rates, and safety precautions should be followed when using any fungicide.
