Diseases of Fruit Plantation Medicinal and Aromatic Crops

Stem rot

Causal organism: Sclerotium rolfsii.

• It is a fungal Disease and soil borne organism.
Symptoms:

• Sclerotial bodies are sorghum like structures then they germinate and multiplies by producing mycelia.
• It colonises and girdle the seedling after infection.
• Once the epidermis destroys, the stem become yellow and root length reduces.
• Finally the death of plant.
Etiology

• Septate mycelia, sclerotial bodies are vegetative structures.
• Asxeual spores: mycelial strands act as a conidia
• Sexual spores: ascospores borne in Apothecium.
• Primary source of inoculum: Sclerotial bodies.
• Secondary source of inoculum: Mycelial strands and through irrigation water.
Life cycle

Epidemiology :- Warm weather, soil temperature 30-33⁰C, relative humidity 65-70 % Susceptible host. Sandy loam /red soil.
Management

• Cut and burn affected plant parts.
• In main field provide good drainage to reduce the soil moisture.
• Chemical application soil drenching with Bordeaux mixture 1% or COC 3 gm/ltr or metalaxyl 1.5 gm/ltr.
• Biological agent Trichoderma viride.
• Low density planting and follow raised bed method.
• Drip irrigation.
• Reduces N application and increase K application