Tapioca (Manihot esculenta)
Leaf spot (Cercospora henningsii, Cercospora vicosae)
Symptoms
- The symptoms of the disease appear on the leaves as small brown coloured necrotic spots surrounded by yellow halo
- The size, shape, colour and form of the leaf spot vary in accordance with the causal organisms.
- Spots are produced on both the sides of leaves.
- On upper surface brown spots with dark border appears.
- On lower side of the leaf spots with grey centre and less distinct margin appear.
- In some cases white spots are also seen on upper surface.
- The infected leaves turn yellow and dry up.
Management
- Field sanitation
- Crop rotation
- Use resistant varieties like S-856, H-97 and Sree Visakham.
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 | Mancozeb 75 WP | Devidayal M-45, Dhanuka M-45 Dithane , Dithane M-45 , Hilthane Hindustan M-45 , Indofil M-45,Izeb M-45 , Manzate , Luzen 45 ,Macoban M-45, Mancosaan , Mancosaan M-45 Manzeb 75 WP , Maneb Manzane M-Guard , Savour M-45 , Tata M-45 Eurofil -NT , Uthane M-45 ,Veera Zinthane | Green | 3 g | 30 g | 600 g | 1500 g | |
| 2 | 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 | 20 g | 400 g | 1000 g | |
Extremely Toxic
Highly Toxic
Moderately Toxic
