Diseases of fruit plantation medicinal and aromatic crops (2+1)

Leaf Spot

Causal organism: Alternaria tennuissima
Symptoms

• Concentric round spot on the leaves.
• Spot size increases and covers the entire leaves.
• Blightening of leaves.
Etiology

• Septate mycelia, any one of the conidia or conidiophore is colored
• Primary sources of inoculum; Dormant mycelia
• Secandry. Sources of Inoculum: Air borne conidia
Epidemiology

• Nutritionally poor soil, temp 28-35 D C, RH 85-90per cent, susceptible host.
Taxonomy

Kingdome: Fungi
Division: Deuteromycota
Class: Deuteromycetes
Order: Moniliales
Family: Dematiaceae
Genus: Alternaria
species: tennuissima

Management

• Collect and destroy affected plant parts
• Increased nutritional status
• Reduce plant population
• Biological agent
• Mancozeb 0.25 % as foliar spray