Diseases of Fruit Plantation Medicinal and Aromatic Crops

Damping off seedlings

Causal organism: Rhizoctonia bataticola
SYMPTOMS

• Initially water soaked lesions appear on the collar region of the plant. After brown discoloration follows the epidermal layer collapse.Seedlings topple down.
Etiology

• Septate mycelia, sub - epidermal haustoria
• Asexual spores are absent and mycelial strands act as conidia
• Sexual spores: Borne on Basidium
• Vegetative structure: Sclerotial bodies
Epidemiology

• Warm weather ,soil temp 280-320 C with optimum moisture and neutral pH
• Primary Source of Inoculum :Sclerotial bodies
• Secondery Source of inoculum: Soil borne mycelial strands
Life cycle

• It is a Deuteromycetes fungus that produces sclerotial bodies which are sorghum seed like vegetative resting structures.
• Under congenial conditions these sclerotial bodies germinate, penetrate inside the host and causes disease.
• The mycelial strands inside the affected host again germinate and cause infection and disease cycle continues.
Management

• Destruction of diseased debris.
• Deep ploughing during summer.
• Crop rotation with non- host crops
• Soil sterilization
• Biological agent
• Soil drenching with Carbendazim (0.1%) or Mancozeb (0.2%).