Wednesday, August 25, 2021

PESTS OF AGRICULTURAL CROPS AND THEIR MANAGEMENT

 

PESTS ON RICE

v  Rice is the staple food for the people throughout the world, especially in India.

v  More than 100 insect species of insects infest rice crop.

v  India is the second largest producer of rice.

     "So dependent upon rice are the Asian countries that throughout history a failure of that crop has caused widespread famine and death."

                                                                      ------Robert F. Chandler, Jr., 1979

1.   Swarming caterpillar or Armyworm:Spodoptera mauritia Noctuidae : Lepidoptera

ü  Sporadic pest appears during July- September.

ü  Larva: Long, cylindrical, smooth and dark to pale green in color, with dull reddish and yellowish dorsal and sub dorsal stripes.

ü  Adult: medium size, Grayish brown moth with black spot near the anterior margin and irregular, wavy, black band along the lateral margin of forewing.. Hindwing whitish brown

ü  Cutting of seedlings in large scale, similar to cattle grazing by nocturnal feeding. Peduncles of ears bitten through in maturing crop.   

Egg period: 7 days; Larval period: 20-25 days; Pupal period: 10-15 days    


ADULT 


EGG MASS



Management

  1. Summer ploughing
  2. Collection and destruction of egg masses
  3. Flood the nursery to expose the hiding larvae to the surface and thus they picked up by birds.
  4. Allow the ducks into the field to feed on the larvae.
  5. Kerosinate the water while irrigation to suffocate and kill the larvae.
  6. Set up light traps to attract adult moths.
  7. Dusting neem cake / pungam cake powder @ 10 kg/ac.
  8. Dusting of wood ash @ 10-12 kg/ac.
  9. Keep neem leaves in bunches at 10 different places per acre.
  10. Drain the water from the nursery and spray Chlorpyriphos 20EC 80 ml or Endosulfan 35 EC 80 ml during late evening.


2.  
Leaf folder: Cnaphalocrocis medinalis: Pyraustidae: Lepidoptera

ü  Egg: Flat transparent, single eggs found on the under surface of the leaves.

ü  Larva: pale yellowish green, smooth, which folds of the leaves and webs them and stays inside the folded leaves and scrapes the green portion.

ü  The scrapped portion becomes white and papery.

ü  Grown up larva pupates inside the folded leaf in a loose silken cocoon.

ü  Adult: Moths are small in size and brownish orange in color. The forewings are light brown in color, with two distinct, dark wavy lines on each wing. The hind wings are light brown in color with one dark, wavy line and dark brown band along the margin.

ü  It completes 3-5 overlapping generation in each year.


EGG

LARVA

PUPA
ADULT 


SILVERY PATCHES ON FOLDED LEAVES

  

ETL:10% - Vegetative stage,  5% - Boot leaf stage

Management: 

  1. Grow Resistant varieties: TNAU LFR 831311, Cauveri, Akash, TKM 6
  2. Clipping of the affected leaves
  3. Keep the bunds clean by  trimming and remove the weeds
  4. Avoid use of excess  nitrogenous fertilizers
  5. Set up light traps to attract and kill the moths
  6. Release Trichogramma chilonis @ 1, 25,000/ha thrice on 37th, 44th & 51st DAT, followed by three sprays of Monocrotophos 35 EC 1000 ml/ha on 58th,65th & 72nd  DAT.
  7. 3% neem oil emulsion with 5 litres of kerosene can be sprayed to control the pest efficiency.
  8. Conserve predators like, spider,Mermithids,Damselfly,Ants,Rove beetles.
  9. Apply  the fungal pathogens like, Beauveria bassiana, Zoopthora radicans
  10. Apply Granulosis virus & NPV.
  11. Spray 5% NSKE and Fenithrothion 50 EC one litre or Chlorpyriphose20 EC 1.25 lit or Phasolone 35 EC 1.5 lit per ha. One spray at boot leaf stage gives adequate protection against RLF.
  12. Carbaryl 50 WP 25 Kg or chlorpyriphos 20 EC 1250 ml/ ha
  13. Avoid resurgence inducing chemicals like Carbofuran.