Fruit Rot and Die Back: Colletotrichum capsici
Symptoms
- As the fungus causes necrosis of tender twigs from the tip backwards the disease is called die-back Infection usually begins when the crop is in flower. Flowers drop and dry up.
- There is profuse shedding of flowers. The flower stalk shrivel and dry up. This drying up spreads from the flower stalks to the stem and subsequently causes die-back of the branches and stem and the branches wither. Partia1lly affected plants bear fruits which are few and of low quality.
- On the surface of the soil the necrotic areas are found separated from the healthy area by a dark brown to black band.
Management
- Use of disease-free seeds is important in preventing the disease. Seed treatment with Thiram or Captan 4g/kg is found to be -effective in eliminating the seed-borne inoculum.
- Good control of the disease has been reported by three sprayings with Ziram O. 25% Captan 0.2% or miltox 0.2%. Chemicals like wettable sulphur 0.2%, copper oxychloride 0.25% and Zineb 0.15% not only reduced the disease incidence but also increased the yield of fruits.
- The first spraying should be given just before flowering and the second at the time of fruit formation.
- Third spraying may be given a fortnight after second spraying.