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

ANTHRACNOSE/ FRUIT ROT of banana

Anthracnose/Fruit rot

Causal organism:Colletotrichum musae (BERK AND CURT)

• It is serious disease of banana growing areas especially in Bihar, Karnataka, Tamil Nadu. Almost all the varieties are susceptible, but severity may vary, owing to severe infection on table varieties. The disease is also called by different names viz., stem end rot, neck rot, back end, finger stalk rot etc.
Symptoms

• Symptoms can be seen at the distal end of banana. The skin turns black, shrivels and covered with characteristic pink colored asexual fruiting body,the acervulus.
• As the disease advances, it spreads to entire finger, and entire bunch resulting in premature fruit ripening.
• The shrivelled fruits use covered with pink spore masses which finally rot. Ripe fruits are more susceptible than unripe fruits
Latent Infection: Usually originates in the field on uninjured fruits. When fruits approach maturity, the fungus resumes activity and causes typical lesions on ripe fruits.
Non-latent Infection: It usually begins during or after harvest as small, peel wounds and continue to develop without dormancy.



Fruit rot of banana
Etiology

• Asexual fruiting body is the Acervulus. Conidiophores are cylindrical, septate, branched and sub- hyaline towards the base.
• Conidia are hyaline, aseptate, oval to elliptical, flattened at the base.

Mode of spread and survival

• Primary source of inoculum: The fungus survives as dormant mycelia in the fallen leaves for considerable time.
• Secondary source of inoculum: Air and water splash borne conidia from the acervuli.

Epidemiology

• The disease is favoured by high temp of 30 -35 0 C and humidity(85 -100%) and also by fruit damage. Black end is the name given due to decaying of stem end on single finger whereas, Finger stalk rot are also known as Santa Marta stem end rot or Neck rot and is common in entire bunches.
• Disease is more abundant during rainy season. Ripe fruits in storage are more susceptible than the unripe fruits in the fields. Cavendish is the most susceptible variety.

Management

• In the field, distal bud should be removed when all the hands have opened to prevent infection.
• Infected materials must be burnt.
• Fruit should be free from infection and as healthy as possible before it is transported, stored and ripened.
• Banana bunches should be harvested at correct stage of maturity. After harvesting of the bunches, they should be transported to the storehouse without causing any bruises to them. The transported bunches should be handled carefully and stored at a cool place at 7-100 c.
• Pre-harvest spray with Carbendazim@ 0.1%, four times at fortnightly interval is highly effective.