Diseases of Fruit Plantation Medicinal and Aromatic Crops

Leaf necrosis

Causal Organism: Ascochyta atropae
Symptoms

• Greyish, white irregular spot with slight depression on the upper surface of leaves.
• The spots coalesce and become necrotic causing defoliation and death of the plants.
Etiology

• Septate inter and intracellular haustoria.
• Asexual spores: Conidia, Vegetative spores (Chlamydospores), Dormant mycelia.
• Sexual spores: Ascospores.
• Primary Source of Inoculum: Dormant mycelia and chlamydospores in soil
• Secondary Source of Inoculum: Air borne Conidia
Epidemiology

• Cool weather. (Temp. 18-22⁰C )
• Relative Humidity 90-95%
• Poor management
• Susceptible host.
Management

• Collect and burn the affected leaves,
• Avoid high density planting.
• Crop rotation with non-host crop
• Proper nutrient management
• Aerial spray of Mancozeb (0.25%)