Colocasia / Taro (Colocasia esculenta)
Leaf blight (Phytophthora colocasiae)
Symptoms
- Lesions can be seen, initially they are small, dark and round but rapidly enlarge and become purplish to brownish in colour.
- Drops of a clear liquid exude from the spots, and turn yellow, orange or purple when dry.
- There is usually chlorotic halo around the spots. As the disease progresses the spots coalesce and have characteristic rings of yellow or brown colour.
- Eventually the whole leaf die.
Management
- Adopt optimum spacing
- Destroy crop stubbles after harvest
- In case of mild infection, leaf roguing can be effective
- Treat the cormels with Trichoderma incorporated (@5g/kg corm) cowdung slurry.
- Apply Trichoderma enriched vermicompost @ 100g/plant at the time of planting and during intercultural operations.
- Treat the cormels with 10% vermiwash before planting.
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 | Metalaxyl 8 WP+ Mancozeb 64 WP | Master, Duet, Kirlaxyl MZ Mancozeb 72 Matco 864, Metal Man 64% WP Metal Plus, Metallic Mix Syscon, Unilax, Redomil MZ 78 | Blue | 2 g | 20 g | 400 g | 1000 g | |
| 3 | Potassium phosphonate 40 SC | Akomin | Green | 4 ml | 40 ml | 800 ml | 2000 ml | |
Extremely Toxic
Highly Toxic
Moderately Toxic
