Agricultural crops :: Pulses :: Blackgram
Rust: Uromyces phaseoli
| Field diagnostic symptoms |
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Numerous spots with pale brown centre and reddish brown margin on leaves, branches and pods
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Defoliation during flower and pod formation
Rust infected plants
Causal agent
Uromyces phaseoli typica Arth. - Autoecious rust
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Uredospores - globose or ellipsoid, single celled, yellowish brown with echinulations
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Teliospores - unicellular, globose or elliptical, pedicellate, chestnut brown in colour
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Pycnia appear on the upper surface of the leaf
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Aecia - cup shaped and orange coloured
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Aeciospores - unicellular, ellipsoid minutely, and verrucose
Rust infected plants - Survival: In soil as teliospores and on crop debris as uredospores
- The fungus also survives on other legume hosts (beans, cowpea, etc.,)
- Primary spread: Sporidia
- Secondary spread: Wind -borne uredospores
Favourable conditions
- Temperature: 21 to 26°C
- Heavy dew during night hours
- Long day hours
Integrated disease management
- Spray any one of the following fungicides at initiation of disease. If necessary, repeat the spray 15 days later.
Mancozeb 72 WP @ 1000g/ha
Wettable sulphur 80 WP @ 1500g/ha
Chlorothalonil 75% WP@ 1000 g/ha
Captan 70% + Hexaconazole 5% WP @ 750ml/ha
Sulphur 85% DP @ 15-20 kg/ha
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