Leaf spot, die back disease, anthracnose (Colletotrichum gleosporioides)

Anthracnose is the most important and serious fungal disease seen throughout the year in Kerala.

Symptoms

• Affects plants of all ages from seedlings to regularly yielding old plants, especially soon after the monsoon.
• In the initial stage of the disease light to dark brown spots surrounded by yellow halo on tender and mature leaves.
• The infected area gradually dries and turn necrotic.
• As the spots enlarge, the necrotic area becomes brittle and it falls off resulting in shot hole symptom on leaves.
• The infection on tender leaves spreads to petiole and subsequently to shoot tip resulting in die back symptom.
• Severely affected plant shows burnt appearance.
• Half matured fruits are more susceptible to the disease.
• Black sunken spots anywhere on the surface of fruits.
• Later spots enlarge and infection progresses deep into the mace and kernel resulting in their rotting and shedding of fruits in large numbers.

Management

• Remove and destroy all fallen leaves and fruits
• Maintain proper spacing between plants at the time of planting
• Provide proper shade
• Spray Pseudomonas fluorescens (20g/l) at monthly intervals during onset of monsoon.
• Add trichoderma enriched cowdung as basal dose at the rate of 5-10 kg per tree

Chemical Control

Extremely Toxic

Highly Toxic

Moderately Toxic

Slightly Toxic