Diseases of Fruit Plantation Medicinal and Aromatic Crops

Stolon rot

Causal organism: Rhizoctonia bataticola & Sclerotium rolfsii
Symtoms

Aerial symptoms:
• Initially yellowing of leaves & stunted growth. advance stages the plants wilts followed by death of above ground parts.
Below ground symtoms:
• Stolons exhibit pinkish brown lesions initially. Which gradually turns into dark brown lesions.
• Later turns to dark brown to black patches that increase in size resulting in soft decay.
Etiology

• Septate mycelia, sub epidermal haustoria
• Asexual spores: Mycelial strands
• Sexual spores: Basidium (Basidiospores)
• Vegetative structure: Sclerotial bodies
Epidemiology

• Warm weather, soil temp 28-32oC. Optimum moisture, neutral pH
• Primary Sources of Inoculum : Sclerotial bodies present in the debris
• Secondary Sources of Inoculum : Soil borne mycelial strands
Taxonomy

Kingdom: Fungi
Division: Deuteromycota
Class: Deuteromycetes
Order: Mycelia sterilia
Family: Mycelia sterilia
Genus: Rhizoctonia
Species: bataticola

Life cycle

• The fungi produces sclerotial bodies these are like sorghum seed like vegetative structures.
• When there are congenial conditions the sclerotial bodies germinate and causes disease the affected host having mycelial strands again they germinate and cause infection that how disease cycle continues.
Management

• Affected debris destruction
• Summer ploughing
• Crop rotation
• Soil sterilization
• Biological agent Tricoderma spp.
• Carbendizim 0.1% or Mancozeb 0.25% as soil drenching.