Shoot Bug:
Symptoms:
- Adult are small, active light brown or dark brown in colour with transparent wings and movable spur on the hind legs.
- Adults and nymphs suck the sap from the plants
- The attacked plants become unhealthy, stunted and yellow.
- The leaves wither from top downwards.
- Cob formation is inhibited and the plants die if attack is severe.
- Honeydew secreted by the bug causes growth of sooty mould on leaves.
Management:
- Cultural Control- Apply balanced fertilizers having adequate N and P to promote better plant growth, that results in reduced damage by shoot bug. Apply manures and fertilizers as per soil test recommendations. After harvest, plough to remove and destroy the stubbles.
- Biological Control- Spray 5% Neem seed kernel extract @ 1000 ml/ 10 lit. of water.
- Chemical Control- Spray Dimethoate 30% EC @ 200 ml or Methyl Demeton 25% EC @ 200 ml dissolve in 250-300 lit. of water/acre.
Aphid:
Symptoms:
- Aphids-Adults are minute, soft bodied, oblong, light green or pale yellow Cornicles. Nymphs are Smaller and greenish.
- Both nymphs and adults suck the sap from plant especially from the leaves.
- As a result the leaves turn yellow and in case of heavy infestation the plants remain stunted.
- Their injury causes oozing of sap which crystallizes on evaporation forming sugary material called “Sugary Disease”.
Management:
- Cultural Control- Balance use of fertilisers, excess of nitrogen and deficiency of potash increase aphid infestation.
- Mechanical Control- Remove aphid infested part at early stage of infestation.
- Biological Control- Release larvae of Crysoperla carnea @ 20,000/acre.
- Chemical Control- Apply any one systemic insecticides like- Oxydemetons Methyl (Metasystox) 25% EC @150 ml or Dimethoate (Rogor) 30% EC @ 160 ml or Imidacloprid (Confidor) 17.8% SL @ 40-50 ml or Thiamethoxam 25% WG @ 40g dissolve in 250-300 lit. of water/acre when aphid population reaches or crosses -Economic threshold Level.
Leaf Blight:
Symptoms:
- The fungus affects the crop at young stage. Small yellowish round to oval spots are seen on the leaves. The spots gradually increase in area into bigger elliptical spots and are straw to greyish brown in the centre with dark brown margins.
Management:
- Cultural Control- Grow resistant cultivers – Deccan, VL 42, Prabhat, KH-5901, PRO-324, PRO-339, ICI-701, F- 7013, F-7012, PEMH 1, PEMH 2, PEMH 3, Paras, Sartaj, Deccan 109, COH-6.
- Chemical Control- Treat the seeds with Captan 50 % WP or Thiram 75 % WP @ 2g/kg. Spray Mancozeb 75% WP @ 600-800g or Captafol 80% WP @400g or Matalaxyl 35 % WS 400g dissolve in 250-300 lit. of water/acre at 10 days interval after first appearance of the disease.
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