Bihar hairy caterpillar:
Symptoms:
- Young larvae feed gregariously on chlorophyll mostly on the under surface of the leaves, due to which the leaves look like brownish-yellow in colour.
- In later stages the larvae eat the leaves from the margin.
- The leaves of the plant give an appearance of net or web
Management:
- Deep summer ploughing.
- Avoid pre monsoon sowing.
- Use optimum seed rate.
- Adequate plant spacing should be provided
- Intercrop soybean either with (early maturing) pigeon pea variety or maize or sorghum in the sequence of 4:2 should be practiced.
- Collect & destroy infested plant parts, egg masses and young larvae.
Field Sanitation: Remove the infested plant parts at least once in 10 days and bury them in compost pit to monitor and reduce the population.
Light Trap: Install one light trap (200W mercury vapour lamp) per hectare to catch the adults of some nocturnal pests such as hairy caterpillar (positively phototropic).
- Apply chlorpyriphos 20 EC @ 1.5 lit/ha or trizophos 40 EC @ 0.8 Lit/ha or quinalphos 25 EC @ 1.5 lit/ha.
- Dust Chlorpyriphos 1.5% DP quinalphos 1.5% @ 25kg/ha when the population is likely to reach 10/m row length (ETL). Repeat it as needed.
Tobacco caterpillar:
Symptoms:
- Larvae feed on the chlorophyll of the leaves.
- The eaten leaves give the appearance of whitish yellow web.
Management:
- Deep summer ploughing.
- Avoid pre-monsoon sowing.
- Optimum seed rate (70-100 kg/ha) should be used.
- Collect and destroy infested plant parts, egg masses and larva.
- Install sex pheromone trap @ 10 traps/ha for early deduction of the pest.
- Erection of bird perches @ 10-12/ha.
- Field Sanitation: Remove the infested plant parts at least once in 10 days and bury them in compost pit to monitor and reduce the populations of tobacco caterpillar. Traps are used for monitoring the pest situation.
- Install one light trap (200W mercury vapour lamp) per hectare to catch the adults of some nocturnal pests such as tobacco caterpillar (positively phototropic).
- Install five sex pheromone traps per hectare (change septa after 3 weeks), specific for male adults of tobacco caterpillar (separate pheromone for each).
- Apply Profenophos 50 % EC @ 1000 ml/ha or deltarnethrin 2.8 EC @ 750 ml/ha
or quinolphos 25 EC @ 1000ml/ha - In case of severe infestation apply polytrin 44% @ 1 lit/ha
or profenophos 50 EC 2.00 lit/ha - Dust Deltamethrin 2.8% EC or quinalphos 1.5% @ 25kg/ha when their population is likely to reach 10/m row length (ETL). Repeat it as needed.
White Fly:
Symptoms:
- Due to attack of the insect the leaves turn yellow and become curled.
- This insect spread the mosaic disease in soybean.
Management:
- Dusting of cow dung ash and spraying of clay suspension as asphyxiants (in small area and low incidence of sucking insects)
- Spray 0.05 % quinalphos 25 EC oxydemeton methyl 25 EC, or dimethoate 30 EC @ 2ml /lit at the crop age of 35-40 days and repeat after 15 days if needed.
Frog eye leaf spot:
Symptoms:
- Light to dark gray or brown areas varying from specks to large blotches appear on seeds.
- The disease primarily affect foliage, but, stems, pods and seeds may also be infected.
- Leaf lesions are circular or angular, at first brown then light brown to ash grey with dark margins.
- The leaf spot may coalesce to form larger spots.
- When lesions are numerous the leaves wither and drop prematurely.
- Lesions on pods are circular to elongate, light sunken and reddish brown.
Management:
- Use healthy or certified seeds.
- Rotate soybean with cereals.
- Completely remove plant residue by clean ploughing the field soon after harvest.
- Seed treatment with Thiram + Carbendazim (2:1) @ 3g/kg seed.
- Spray Mancozeb @ 2.5g/lit or Carbendazim 1g/lit.
Anthracnose/pod blight:
Symptoms:
- Infected seeds become shriveled, mouldy and brown.
- Symptoms on cotyledons appear as dark brown sunken cankers.
- In early stage, irregular brown lesions appear on leaves, stems and pods.
- In advanced stages, the infected tissues are covered with black fruiting bodies of fungus.
- Under high humidity, symptoms on leaves are veinal necrosis, leaf rolling, cankers on petioles premature defoliation
Management:
- Use healthy or certified seeds.
- Rotate soybean with cereals.
- Do not cultivate when the foliage is wet.
- Completely remove plant residue by clean ploughing the field soon after harvest.
- Destroy last years infected stubble.
- Maintain well drained field.
- Seed treatment with Thiram or Captan or Carbendazim 3 g/kg and
- Use Mancozeb @ 2.5g/l as spray or Carbendazim 1g/L.
Bacterial blight:
Symptoms:
- Seeds may develop raised or sunken lesions and become shriveled and discolored.
- Small, angular, translucent, water-soaked, yellow to light brown spots appear on leaves.
- Young leaves are most infected and are destroyed, stunted and chlorotic.
- Angular lesions enlarge and merge to produce large, irregular dead areas.
- Early defoliation of lower leaves may occur.
- Large, black lesions develop on stems and petioles.
Management:
- Deep summer poughing.
- Use healthy/certified seeds.
- Destroy infected crop debris
- Seed treatment with streptocyclin @ 250 ppm (2.5 g/10 kg seeds).
- Application of any copper fungicides @ 2 g/lit along with streptocyclin at the rate of 250 ppm (2.5 g/10 lit water).
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