Diseases of Fruit Plantation Medicinal and Aromatic Crops

Leaf blight

Causal organism: Alternaria alternata
Symptoms

• Lower most leaves first infected &disease later develop on upper leaves.
• The infected leaves shows round to oval to irregular or slightly irregular dark brown spots on the upper surface of the leaves with concentric rings.
• Spot size increases and covers the entire leaves Later Blightening & detaching of leaves
Etiology

• Septate mycelia, coloured muricate conidia
Epidemiology

• Nutritionally poor soil, temp 28-32^oC, RH 85-90per cent, susceptible host.
• Primary Sources of Inoculum : Dormant mycelia
• Secondary Sources of Inoculum : Air borne conidia
Taxonomy

Kingdom: Fungi
Division: Deuteromycota
Class: Deuteromycetes
Order: Moniliales
Family: Dematiaceae
Genus: Alternaria
Species: alternata

Management

• Collect and destroy affected plant parts
• Proper nutritional management.
• Reduce plant population
• Mancozeb 0.25% as aerial spray