Diseases of Fruit Plantation Medicinal and Aromatic Crops

Brown eye spot

Causal organism: Cercospora coffeicola Botrytis & Cke.
Disease has been reported from all the known coffee growing countries. Mostly the seedlings in nursery & young plants in the new clearings suffer to a large extent when proper over head shade is lacking.
Symptoms

• Leaves show circular necrotic spots with dark brown margin & light brown or pale centre.
• Necrotic spots increase in size, central portion turns light grey due to sporulation by the fungus and collapses leaving a hole at the centre.
• Infected leaves turn yellow causing pre-mature defoliation.
Favourable factors

• Inadequate overhead shade in the new clearing, sudden exposure of the seedlings to bright sun shine after the removal of nursery pandal shade, hot humid conditions during Apr-June and Sep-Nov are the predisposing factors for the disease development.
Collateral hosts & mode of survival

• The pathogen survives in the soil on the fallen debris even upto 35 weeks.
• Bidens pilosa, Chenopodium ambrosoide, Ricinus communi etc, the commonly occurring weeds in coffee plantations
Management

• Maintain good overhead shades in the new clearings and spray 1.0% Bordeaux mixture.
• In nursery, grow plants under pandal shade to avoid exposure to sun.
• Provide adequate mulch to conserve soil moisture for the young plants in the new clearings.
• Spray Captan @ (0.2%) at 30 days interval.