Anil Thapa Department of horticulture Agriculture and forestry University

1. CURRENT STATUS AND POTENTIAL OF
BIOLOGICAL CONTROL IN GARDEN PEA
(Pisum sativum)
SUBMITTED BY
ANIL THAPA
HRT-11M
Department of Horticulture
Agriculture and forestry University

2. Biological Control
• Natural control strategies that
employ biological agents for pest
suppression.
• Usually refers to the practice of
rearing and releasing natural
enemies: parasites, predators and
pathogens.
• Management activity that is
designed to protect or conserve
natural enemies.

3. Charles Valentine Riley
“Father of Modern Biological Control”
and the first person who import mites
to control grapevine Phyllosera

4. Biological control started to emerge in 1870 in
USA.
First international shipment was made by Riley
to France to help fight against grapevine disease.
The first importation of parasitoid into the US
was of Cotesia glomerata from Europe to control
cabbage white butterfly

5. Strategies of Biological control
 Importation
• Also known as Classical biological control
• Involves the introduction of pest’s natural enemy to a
new location where they do not occur naturally.
• One of the earliest success was achieved in
controlling cottony cushion scale (Icerya purchasi) in
Australia by using predatory vadalia beetle (Rodolia
cardinalis).

6.  Augmentation (Add what you need)
• Involves the supplemental release of natural enemies,
boosting the naturally occuring population.
Periodic releases of Augmentation
 Inoculative release
• Release of few bio-control agents at different interval,
allowing them to reproduce themselves.
• Constitutes prevention better than cure.
 Innundative release
• Mass culture and release of natural enemies to supress
the pest population directly.

7.  Conservation (Use what you have)
• Involves the measures that increase the longevity
and reproduction of natural enemies in an
environment.

8. Mechanism of Biological Control
 Competition: Use or defense of resources (space and
nutrition) by one individual (microorganism) that
reduces the availability of that resource to others.
 Antibiosis: Condition in which one or more metabolites
secreted by an organism have harmful effect on the
others.
 Predation: One organism capture and feed on the other.
 Parasitism: Relationship between host and pathogen.

9. Biological Control Agents
In “The manual of Biological Control Agents” (Copping, 2004), there
are 373 entries of which,
• Micro-organism (112)
• macro-organism (126)
• Natural products (57)
• Semio chemicals (55)
• Genes (19)

10. Macro-organism as bio-control agents
Assassin bug feeding on Colorado potato
Beetle larva
Parasitic wasp larva feeding on tomato
Hornworm caterpillar

11. Micro-organisms as Bio-control Agents
Bacillus subtilis
Trichoderma harzianum
Verticillium lecani
Bacillus thuringensis against
Lepidoptera
Ampelomyces quisqualis against
powdery mildew
Cytoplasmic polyhedrosis controls
the larva of butterflies.

12. Biological Control of
Garden Pea

13. Insect pests of garden pea
 Pea aphid (Acyrthosiphon pisum)
• Feeds on sap of the leaves and stem,
resulting in deformation, wilting, or
death of the plant.
• Honeydew secretion, resulting into
secondary bacterial and viral
infection.
• Parasitized by several species of Hymenoptera and a few
Diptera species.
• Release 1st instar larvae of green lacewing (Chrysoperla
zastrow sillemi) @ 4000/acre.
• Innundative release of Coccinella septempunctata @ 1000
adults/4000 sq.m. is recommended.

14.  Pea pod borer (Etiella zinckenella)
• Larva develops within the pod and
accumulates causing soft, rotten
patches on the pod
• The use of Bacillus thuringiensis (Bt) based microbial
insecticides.
• These bacterial insecticides like Nuclear Polyhedrosis
Virus (NPV), which is target specific and exert no effect
on beneficial organisms (e.g. parasitoids and predators).
• Various insectivorous birds and use of bird perches have
been effective predators of pod borer larvae.
• Various plant extracts can also be used effectively.

15.  Leaf miner (Liriomyza huidobrensis)
• White tunnels appear in the leaves.
• Infested leaves drop before the fall
season.
• Slows down the plant growth.
• Give your plants a good spraying with neem before their
appearance.
• Poison will not injure either the eggs or the adult flies.
Remember that the leaf miner larva are your target.

16. Nematodes
• Nematodes are very small plant pathogens, affecting the
plants by sucking plant sap and hiding the symptoms
for a longer time.
Biological control
• Paecilomyces lilacinus @ 108 spore (pinch)/kg seed as
seed treatment for controlling nematodes.
• Aspergillus niger @ 108 spore (pinch)/kg seed as seed
treatment for controlling nematodes.

17.  Root rots (Aphanomyces euteiches f. sp.)
• Water soaked spots, softening, and slight discoloration of
the taproot and lower stems of the infected plants.
• Oospores from decayed roots released to soil which serve
as a inoculum in years to come.
Biological control
• Soil amendment with pearl millet residues, mustard cake
or mustard pod straw.
• Seed treatment with Bacillus subtilis, Pseudomonas
fluroscens or Gliocladium virens.
• Soil application of Trichoderma harzianum or spraying
of B. subtilis is recommended.
Diseases and their management

18. Damping off (Rhizoctonia solani)
• Serious disease of seedlings in the nursery, resulting into
the lodging of young seedlings due to stem rot or root rot.
Biological control
• Treatment with 30 g of M. cinnamomi inoculum has a
complete control.
• Granular application of Trichoderma harzianum inhibits
the disease severity.
• Seed treatment using 10% Pelgel enhanced the efficacy of
Trichoderma.

19.  Powdery mildew (Erysiphe pisi)
• Powdery white mycelium and spores appear on leaf and stem
surfaces
• Black necrotic spot develops.
Biological control
• Non-fungicide products, such as soluble silicon, oils, salts and
plant extracts are being used.
• Effectively controlled by mycolytic bacteria, mycophagous
arthropods, fungi, yeasts etc. (Sara and Diego, 2012).
• spraying of azadirachtin EC, a natural product of neem.
with bergenin, a natural product from Flueggea microcarpa
with ajoene, a constituent of garlic
with exudates from Scletorium rolfsii (Pandey et al. 2007).

20. CONCLUSION
 Biological control trials have involved a number of
natural antagonists, biofungicides, parasites, predators,
parasitoids
 Use of natural enemies and resistant varieties is quite in
practice.
 Furthermore, it is sensible to use additional genes for
resistance to this pathogen in pea breeding programmes.