Orchid (Dendrobium sp.)
Black Rot(Pythium spp. and Phytophthora spp)
Symptoms
- Infections usually start on the roots or basal portion of the pseudobulb / stem.
- All plant parts are susceptible to this disease.
- Pseudobulbs / stem, roots or rhizomes show infections as purplish-black.
- Leaf to fall from the plant with a slight jarring.
Management
- Isolate it from other plants; remove infected tissue with a sterile tool.
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 | Potassium phosphonate 40 SC | Akomin | Green | 4 ml/ litre of water | 40 ml | 800 ml | 2000 ml | |
| 2 | Mancozeb 64 +Metalaxyl 8 WP | Syscon | Blue | 2 g /litre of water | 20 g | 400 g | 1000 g | Both spraying and soil drenching |
| 3 | Fosetyl-Al 80 WP | Aliette | Green | 2 g/ litre of water | 20 g | 400 g | 1000 g | Both spraying and soil drenching |
Extremely Toxic
Highly Toxic
Moderately Toxic
