Symptoms

a. Pre Harvest Symptoms :

1. Symptoms on Leaves

• Leaf spots: Small, irregular, dark brown to black lesions that may coalesce to form larger necrotic patches.
• Leaf blight: Severe infections may cause extensive drying and premature leaf drop.

2. Symptoms on Flowers (Panicles)

• Flower blight: Dark brown to black spots develop on flowers, leading to flower abortion.
• Leaf blight: Reduced fruit set due to flower necrosis.

3. Symptoms on Fruits

• Fruit spots: Circular, sunken, dark brown to black lesions on immature or mature fruits.
• Cracked lesions: Lesions may expand, crack, and expose the underlying tissue.

4. Symptoms on Twigs

• Twig dieback: Dark lesions appear on twigs, eventually causing them to dry out and die.

b. Post-Harvest Symptoms:

1. Fruit Rot:

• Latent infections become visible as dark brown or black sunken spots on ripe fruits.
• Spots may enlarge and merge, causing extensive rot.

2. Spore Development:

• Pinkish or orange spore masses may form on the lesions under humid conditions.

3. Internal Decay:

• Advanced infections can infect the pulp, causing internal fruit breakdown and making it unsuitable for consumption or sale.

4. Storage Issues:

Causes

• High humidity (above 85%) and temperatures between 25°C and 30°C favor the development of the disease.
• Extended periods of leaf wetness due to rain or dew are critical for infection.
• Dense canopies and poor ventilation in orchards exacerbate disease conditions.

Geographical Distribution

Causes

• Found in major mango-producing regions worldwide, particularly in India, Southeast Asia, Africa, Central and South America.
• In India, mango anthracnose is prevalent in regions with high humidity and warm temperatures, the disease is commonly reported in major mango-growing states such as Uttar Pradesh, Andhra Pradesh, Telangana, Karnataka, Maharashtra, West Bengal, Bihar and Tamil Nadu
• In Karnataka, mango anthracnose is commonly observed in the major mango-growing districts, particularly in areas with high humidity and conducive climatic conditions. The disease is reported in districts such as Kolar, Chikkaballapur, Tumkur, Ramanagara, Mysuru, Bengaluru Rural, Chitradurga and Davangere

Loss Percentage

• Infected orchards can suffer yield losses of 20-60%.
• Severe infections, particularly in post-harvest stages, can cause up to 100% loss of marketable fruits.

Disease Cycle

• 1. Primary Inoculum: The fungus survives as dormant mycelium or conidia on infected plant debris, bark, and older lesions.
• 2. Dispersal: Conidia are dispersed by rain splash, wind, and insects to new infection sites.
• 3. Infection: Under suitable conditions (high humidity and warm temperatures), conidia germinate and penetrate plant tissues.
• 4. Secondary Spread: Continuous wetness promotes rapid production and spread of secondary conidia, leading to repeated infection cycles.

Management Strategies

1. Cultural Control:

• Regular pruning to improve airflow and reduce humidity in the canopy.
• Remove and destroy infected plant debris and fruits.
• Maintain adequate spacing between trees to enhance ventilation.
• Avoid overhead irrigation to reduce leaf wetness.

2. Physical Control:

3. Biological Control:

• Mix 3 to 5 kg of Nisarga/tree and 150g/tree of Annapurna and broadcast over one acre before planting.

4. Chemical Control:

• Spray fungicides such as Multiplex Nagcoper 2-3 g/L or Multiplex Jodi 2g/L or Multiplex Duo Care 1-1.5ml/L or Multiplex Ziddhi 2g/L or Multiplex Tecsulp 2g/L at regular intervals, especially during flowering and fruiting stages.

• Apply systemic fungicides like Multiplex Vishesh 2g/L or Multiplex Tecozo 1-2 ml/L during wet seasons.