Welcome to Official Portal of Agriculture Department, Sikkim!

  • Change Font Size:
  • -A
  • |
  • A
  • |
  • +A
  • ||
  • Change Theme:
 
logo user
emblem userSign In
Home About Us Contact Us

More Menu

Integrated Pest Management

Integrated Pest Management (IPM):

Rapeseed-mustard crops are highly vulnerable to insect-pests at different stages of growth. Of which mustard aphid (Lipaphis erysimi) is the key pest followed by white mustard saw fly (Athalia lugens proxima), painted bug (Bagrada crusiferarum), pea leaf miner and bihar hairy caterpillar (Diacrisia obliqua).

Diseases to a large extent are responsible for low and unstable production of rapeseed-mustard and cause the yield losses ranging from 10-90%. The major diseases are White rust, Alternaria blight, and downy mildew and minor diseases are powdery mildew, bacterial rot and Sclerotinia stem rot.

Integrated pest management package for rape seed-mustard crop of Sikkim, recommended by the Central Integrated Pest Management Center, Gangtok, Sikkim is as follows:

1. Pest Monitoring: The objective of pest monitoring is to detect the initial development of pest and disease and also bio-control potentials in the field situation. For this the following operations should be done:

a) Field surveys:
Survey, surveillance and monitoring of all the important pest should be done regularly i.e. weekly in general and twice a week during flowering/pod formation stage.

b) Field scounting: Based on the observations, the farmers at village level have to be mobi-with green colour, diseased plant/leaves with yellow colour. While drawing the pest and the defenders the character should be taken to draw them at appropriate part of plant, where they are seen at the time of observations. The common name of pests and defenders and their population count should also be given along with diagram. The weather factors should be reflected in the chart by drawing the diagram of sun just above the plant it the attribute is sunny. If cloudy, the clouds may be drawn in place of sun. In case of partially sunny, the diagram of sun may be half marked with clouds.

c) Group Discussion and Decision making: The observations recorded in the previous and current charts should be discussed among the farmers by raising questions relating to change in pest and defender population in relation to crop stage, soil condition, weather factor such as rainy, cloudy or sunny etc. The group may evolve a strategy based on weekly AESA, ETL and corresponding change in Pest: Defender ratio and take judicious decision for specific pest management practices.

2. Economic Threshold Levels (ETLS): To determine ETL of mustard aphid, observe 30-40 widely scattered plants in a hectare or per location or per spot, twice a week and then count the number of aphids (nymphs and adults) or measure the colony size (in centimeter) on 10 cm terminal portion of the central shoot or observe 250 plants/ha selected randomly from all the sides of the field to work the per cent plants infested.

Pest & Economic Threshold Levels (ETLs)

Mustard Aphid: 20-50 aphids/10 cm terminal portion of the central shoot or 0.5-1.0 cm colony size on terminal portion of the central shoot or 30-40% aphid colonies or 30-40% plants infested by the aphid colonies (mother aphid with few young ones).

3. Integrated Pest Management Strategies:
 

  1. Deep summer ploughing wherever possible; 
  2. Destruction of plant debris of previous crops; 
  3. Grow resistant/tolerant varieties; 
  4. Early sowing of crop to escape the mustard aphid and major disease damage; 
  5. Use recommended doses of fertilizers to ensure adequate vigour in plants; 
  6. Irrigate the crop in 4th week after sowing to reduce the painted bug incidence, if present.

b) Mechanical Practices:

  1. Collection and destruction of early instar larvae/carterpillar; 
  2. Collection and destruction of egg masses; 
  3. Removal of aphid infested twigs in early stage.


c) Biological Control Practices: Conserve the natural bio-control agents namely coccinelids, chrysopids and syrphids by selecting the safe insecticides (endosulfan) safer for predators and pollinators, proper timing of spray (morning and evening hours) and following the need based application of insecticide/fungicide depending upon the economic threshold levels or disease appearance. The following are the defender of mustard crop:
 

  1. Chrysopa: Green lacewing adults are delicate, light green insect with net like wings. The eggs are stalked. Its grubs possess sickle shaped mouth parts, wander on plants in search of soft bodied insects and prey voraciously on them. 
  2. Lady Bird Beetle: The lady bird beetles are predatory. The eggs are yellowish, larvae blackish and fast moving, pupae are also blackish and are resting stage. The adults are small in size yellowish in colour and having black spots. The adults and grubs feed on aphids. 
  3. Syrphid Fly: The larva is whitish in colour having sharp mouth parts which feed on aphids. The adult does not feed. These are also called hover flies and look like a slender housefly.

Integrated Pest management of important insect pests and diseases are as follows:

A) INSECT-PESTS:

  • Grow improve varieties; 
  • Crop should be sown early at optimum time recommended for particular area. The crop sown before 5th October in north India often escape aphid damage; 
  • Use balanced dose of fertilizers. Over dosing of fertilizer particularly nitrogen would attract more aphids. 
  • Plucking and destruction of infested twigs is very useful. It should be done 2-3 times at 10 days interval early in the crop season; 
  • Spray the crop before the aphid reaches the economic –threshold level (ETL);

Mustard saw fly:

  • Follow the crop sanitation practices; 
  • Timely irrigation helps in killing larvae through drowning.

Painted bug:

  • Follow clean cultivation by weeding, hoeing and burn the debris around the field;
  • Apply first irrigation 3-4 weeks after sowing wherever possible;
  • Thresh the crop as early as possible to avoid further losses and dispose off plant material immediately.

Pea leaf miner:

  • Pluck all the infested leaves and burn them to kill the larvae and pupae resting inside.

Bihar hairy caterpillar:

  • Mechanical control is a non chemical eco-friendly method which provides an effective check by removing infested leaves containing first/second instar gregarious phase larvae and dip them in kerosenized water or insecticidal solution;
  • Removal of alternative host plants from the surroundings is beneficial.