Citrus anthracnose
Causal organism: Colletotrichum gloeosporioides Symptoms
- The disease causes defoliation and tip drying of twigs, called whither tip.
- Shedding of leaves and dieback of twigs.
- Acervuli appear as black dots on the dead twigs. Light green spots appear which later turn brown.
- The pathogen also infects the stem-end of immature fruits causing fruit drop.
- In severe cases branches also show die back symptoms.
Etiology
- Septate mycelia, asexual fruiting body is the –acervulus and setae are present
- Primary source of inoculum: Dormant mycelia
- Secondary source of inoculum: Conidia produced in Acervulus
Epidemiology
- Disease is favoured by warm weather at temperature of 30-32oC, RH 80-85%, cloudy weather and presence of susceptible host.
Management
- Collect affected leaves and burn them.
- Avoid excess N application.
- Irrigation during summer is required.
- Chemicals: Carbendazim @-1.5gm/lt and Benomyl- @1gm/lt
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Last modified: Friday, 20 January 2012, 1:24 PM