Cabbage (Brassica oleracea var. capitata)
Leaf Spot and Blight (Alternaria brassicae and A. brassicola)
Symptoms
- It is a destructive disease on seed crop. Older leaves are more susceptible.
- The initial symptoms are in the form of small dark yellow spots on the leaf surface.
- Later on the spots enlarge to circular areas with concentric rings and possibly surrounded by yellow halos.
- In severe cases, the entire plant defoliates.
- Violets to tan spots develop on infected cabbage seed pods which intensifies in wet weather.
Management
- Use of disease free seeds, practicing proper crop rotation and seed treatment with hot water (50oC for 30 minutes) helps to minimize the disease incidence.
Chemical Control
| Sl.No | Generic Name | Trade Name | Color code | Dosage/litre | Knapsack Sprayer (Capacity 10L) | Recommendation | Remarks | |
|---|---|---|---|---|---|---|---|---|
| Dosage/acre (200 L) | Dosage/hectare (500 L) | |||||||
| 1 | Tridemorph 80 EC | Calixin | Blue | 1 ml/litre of water | 10 ml | 200 ml | 500 ml | First foliar spraying followed by spraying with Mancozeb |
| 2 | Mancozeb 75 WP | Devidayal M-45, Dhanuka M 45, Dhanuka M-45, Dithane, Dithane M-45, Hilthane, Hindustan M 45, Indofil M 45, Izeb M-45 Manzate, Luzen-45, Macoban, Macoban M-45, Mancosaan, Mancosaan M-45, Maneb Manzane, M-Guard, Savour M 45, Tata M-45 Eurofil-NT, Uthane M-45, Veera, Zinthane | Green | 3 g/litre of water | 30 g | 600 g | 1500 g | - |
| 3 | Copper oxychloride 50 WP | Bensaan, Blitox, Blue copper, Bluetrox, Copter, Cupramar, Cuprina, Dhanucop, Fytolan, Fytox, Fytran, Fytolan, Hilcopper, Killex copper, Maincop Dhanucop, Star cop, Tagcop, Trucop | Blue | 2 g/litre of water | 20 g | 400 g | 1000 g | - |
Extremely Toxic
Highly Toxic
Moderately Toxic
