Rice (Oryza sativa)
Brown leaf spot( Helminthosporium oryzae )
Symptoms
- The symptoms of the disease are found on leaves, glumes , coleoptile, leaf sheaths, and panicle branches and rarely on roots of young seedlings and stems.
- Typical spots are small, oval or circular in shape and are dark brown or purplish in colour.
- Fully developed lesions are oval, brown with gray or whitish centre of about 1 cm long, with dark reddish brown margin.
- Numerous such spots occurring on leaves cause withering.
- Glumes also show similar dark brown spots.In such grains, the endosperm turn black in colour.
- The disease is usually seen in the last stages of the first crop. However, in the second crop, the disease can be found under the nursery stage itself.
- The infected seed on germination show black spots on the coleoptile and cause death of the seedlings (seedling blight).
- The disease is transmitted through seeds and air.
Management
- Use certified and healthy seeds.
- Use resistant varieties Kanchana, Remya, IR-36 etc.
- Treat seeds with hot water (53-54oC) for 10-12 minutes.
Chemical Control
| Sl.No | Generic Name | Trade Name | Color code | Dosage/litre | Knapsack Sprayer (Capacity 10L) | Dosage/acre (200 L) | Dosage/hectare (500 L) | Remarks |
|---|---|---|---|---|---|---|---|---|
| 1 | 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 - 4 g/ litre of water | 30 - 40 g | 0.6 - 0.8 kg | 1.5 - 2 kg | |
| 2 | Propineb 70 WP | Antracol 50 WP | Blue | 2.5 g/ litre of water | 25 g | 500 g | 1.25 kg | |
| 3 | Carbendazim 12 + Mancozeb 63 WP | Companion, Dasma, Hi-Jip, Kuber, Macoban , Macoban C Trophy, Merger, Nagarjuna Combi+, Revive 750, Riper, Saaf, Sixer, Sprint, Stuff | Green | 2 g/ litre of water | 20 g | 400 g | 1000 g | |
| 4 | Hexaconazole 5 EC | Alert Creeper, Contaf, Corazole, Danzole, Force 5C, Hexaan, Hexacone, Hexadhan, Hexamax, Hexan, Hexazole, Mainex EC, Sitara, Strike, Titan, Topper, Topper plus EC, Xantho | Blue | 1 ml/ litre of water | 10 ml | 200 ml | 500 ml |
Extremely Toxic
Highly Toxic
Moderately Toxic
