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

Sooty mould

Causal organism: Capnodium psidii
Symptoms

• It is an ectophytic fungus and not the parasite. Black superficial growth appear on entire surface of leaf and twigs. Under dry spell such infected leaves curl & shrivel.
• At flowering stage the disease causes reduced fruit set and fruit fall. Blackish powder like fungal conidial structures covere the leaf surface.
• The fungus develops on the excreta and honey secretions of insects as black sooty mass of spores and will not invade plant tissue.
• Disease severity increases with the increase in population of leaf hoppers, aphids and other insects. This disease effects the photosynthesis activity and decrease in yield.
Mode of spread

• Primary source of inoculums is Dormant mycelia :
• Secondary source of inoculum: Air borne conidia: Spread through Insects, aphids and wind
Epidemiology

• 28 -320C temperature, 85-90% RH, Warm Weather and susceptible host
Management

• Sprays of wettable sulphur (0.2%) along with the insecticide Dimethoate @ (1.5ml/lit)
• Spray of 1% starch solution makes flakes of the fungus and due to small wind falls of from the plant.