Anthracnose

Symptom

The disease produce leaf spots, leaf blight, blossom blight, withered tip, twig blight and fruit rot symptoms. Tender shoots and foliage are easily affected with sunken dark brown lesions which coalesce and ultimately resulting in leaf blight and die back of young branches.

Older twigs may also be infected through wounds, which in severe cases may be fatal. Black spots develop on panicles. Severe infection destroys the entire inflorescence resulting in failure of fruit setting. Young infected fruits develop sunken dark brown to black spots, shrivel and drop off.

Fruits infected at mature stage carry the fungus into storage and cause considerable loss during storage, transit and marketing. On the infected tissues, pinkish to dark brown dots representing the fruiting bodies of the fungus are produced in large numbers. High humidity, frequent rains and the temperature range of 24- 32°C is ideal for disease development. (C.O.: Colletotrichum gloeosporioides).

Management

The diseased twigs should be pruned and burnt along with fallen leaves. Spray Pseudomonas fluorescens (20 gram/litre of water) at 3 weeks interval commencing from October on flower branches.

Alternatively, spray Bordeaux mixture 1% or Copper oxychloride 50 WP (2 gram/litre of water) or Carbendazim 50 WP (1 gram/litre of water) at 15 days interval during flowering to control blossom infection. Spraying of Bordeaux mixture 1% or Copper oxychloride 50 WP (2.5 gram/litre of water) or Mancozeb 75 WP (3 gram/litre of water) is recommended for the control of foliar infection.

Before storage, treat harvested fruits with hot water, (50-55°C) for 15 minutes. Postharvest anthracnose can be controlled by dipping fruits in Carbendazim 50 WP (1 gram/litre of water) or Bordeaux mixture 1% or Copper oxychloride 50 WP (2.5 gram/litre of water) or Mancozeb 75 WP (3 gram/litre of water).