Hi
Disease management
1. Seedling Blight
Ill drained, damp and low lying localities should be avoided for sowing castor.
Seed dressing with 4gms g Trichoderma viride formulation and 3g metalaxyl per kg seed can reduce disease incidence. Soil drenching with copper oxychloride @3g /lit or metalaxyl 2g/lit is also useful.
2. Alternaria Blight
Seed treatment may be useful in combating the initial phase of the disease.
Use of healthy seed and treat the seed with Captan or Thiram @ 3g/kg seed or spray Mancozab at 2.5g/lit concentration at an interval of 15days commencing from 90days of crop growth.
3. Rust
The disease is reported to be successfully controlled by spraying the crop with fine sulphur powder @20-30kg / hec.
Spraying of Tridemorph 1 ml/litre of water or Mancozeb 2.5 g/litre of water minimises disease spread.
4. Cercospora Leaf Spot
Spraying with Bordeaux mixture or other copper fungicides may help to bring the disease under check; but where the cultures of Eri-silk worm are maintained on castor plants, spraying would not be desirable.
Use of resistant varieties would be the most effective method for combating the disease.
Spraying twice with mancozeb 2.5g/lit or Carbendazim 1g/lit at 10-15 day interval reduces the disease incidence.
Treat the seed with Thiram or Captan 3gm/kg seed.
5. Powdery mildew
When weather is comparatively dry spray twice Wettable Sulphur 3g/lit at 15 days interval , starting from 3 months after sowing.
Spray 1ml Hexaconazole or 2ml Dinocap /litre of water at fortnight intervals. The variety jwala is resistant to this disease.
For more details visit
Ikisan - Disease of Castor
Regards
Harish
