Rubber (Hevea brasiliensis)
Corynespora leaf spot (Corynespora cassiicola)
Symptoms
- The disease is prevalent in nurseries (Nov-May) and mature plantations (Jan-May).
- Large spots with brown margin and pale centre are formed, which later fall off forming shot holes.
- On mature trees, light green leaves during refoliation are more susceptible.
- Defoliation and dieback of twigs are also noticed.
Management
- Shading in nursery reduces incidence.
- Spraying mancozeb (2 g/l) or carbendazim (1 g/l) or Bordeaux mixture 1 per cent is recommended.
- In mature rubber, micronized spraying with oil-dispersible copper oxychloride dispersed in spray oil (1:5 proportion) at light green stage of leaves is effective.
- In mature trees high volume spraying with mancozeb 0.2 per cent, carbendazim 0.05 per cent or Bordeaux mixture 1 per cent at 2-3 week intervals during refoliation is effective.
- Micron spraying with oil dispersible mancozeb 70 per cent @ 7 kg dispersed in 40 l/ha spray oil is also effective.
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 | 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 | |
| 2 | 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 | |
Extremely Toxic
Highly Toxic
Moderately Toxic
