Disease of Sweet Potato
1. Leaf Spot:
Large brown spots appear on leaves.
This disease can be controlled by spying with Zineb (Dithane Z- 78) or Mancozeb (Dithane M – 45) @ gm pre liter of water at an interval of 15 days.
2. Black Rot:
It is primarily a storage rot of tubers but may also occur in the filed, in the filed. Infested foliage become yellow and sticky in appearance and black canker are seen on the portion underground and grey black circular spots occur on fleshy roots.
i) Careful sorting of tubers before storage and rotation of crops are helpful in reducing the incidence of the disease.
ii) The seed tubers should be treated with mercuric chloride solution ( 1 in 1000 ) or 2.5 per cent borax solution.
3. Soft Rot:
Storage rot of tubers and their tissue become soft and stringy.
i) Avoiding brushing and injuring the tubers at harvesting is the best method of controlling this disease.
ii) The walls and floors of storage room should be disinfected before the storing tubers.