Diseases of Fruit Plantation Medicinal and Aromatic Crops

Red root rot disease

Red Root rot
Causal organism: Poria hypolateritia Berk.
Symptoms


• It occurs in India, Malaysia and Sri Lanka.
• In India it is noticed in Assam and Tamil Nadu.
• The fungus is confined to the underground parts. When bark is lifted, characteristic flat, black rhizomorphs ars exposed
• These strands form branched markings on the surface of the wood.
• The strands vary in colour from pink to brown or black according to age.
• The root has generally a mottled appearance of red and white.
• Plants of one to two years age are killed more speedily than the older bushes. The mycelium spreads throughout the cortex and wood and which may extend up to the stem within the wood.
• The bark is softened and wood may be discoloured as bluish black.
• On the bark the conidial stage appears in the form of reddish tufts at the collar region.
• The conidia are of two types, thin and thick walled.
• Perithecia appear on the bark at a later stage.
• Perithecia are small, dark red bodies, round shaped at the bottom and drawn into a short conical neck above. Each perithecia contains numerous asci without paraphyses.
• The asci are cylindrical with a short stalk. Each ascus contain eight ascospores.
• The fungus lives as a saprophyte on the pieces of fallen wood of several trees.
• It spreads mostly through the rhizomorphs present in soil.
• The spores are distributed by wind