This document discusses biological control of plant diseases. It defines biological control as using living organisms to reduce plant pathogen populations and disease incidence. The mechanisms of biological control include competition for resources between beneficial microbes and pathogens, antibiosis where beneficial microbes secrete antibiotics, predation of pathogens, and parasitism of pathogens. Common biocontrol agents used are species of Trichoderma, Aspergillus, Gliocladium, Pseudomonas, and Bacillus. These can be applied through seed treatment, soil application, or foliar sprays. Biological control works by directly killing pathogens or competing with them for space and nutrients. Diseases that can be managed with biological control include sheath blight of rice, w

1. BIOLOGICALCONTROL OF PLANT DISEASES
DR. RAJBIR SINGH
Assistant Professor
Department of Plant Pathology
Gochar Mahavidyalaya, Rampur Maniharan, Saharanpur (UP), India
Affiliated to Ch. Charan Singh University, Meerut (UP), India
Email: rajbir25805@yahoo.com, rajbirsingh2810@gmail.com
Cell No. 91-9456613374

2. Biological Control
Control of organism by organism
Garret, 1965 – “Any condition under which
or practice where by survival or activity of
pathogen is reduced through the agency of
any other living organism (except man
himself) with the result that there is
reduction in the incidence of the disease
caused by the pathogen”

3. Baker and Cook, 1983
“Biological Control is the reduction of
the amount or disease producing
activity of a pathogen accomplished by
one or more organisms other than
man”

4. Mechanism of Biological control
Antagonism
1. Competition– “Use or defense of a resources
(space & nutrition) by one individual (micro-
organism) that reduce the availability of that
resource to others”

5. 2. Antibiosis – “Condition in which one or more
metabolites (antibiotic substances) secreted
by an organism which have harmful effect
on the others”
Exp. – T. viridi produce Viridin

6. 3. Predation – “Relationship between organism
in which one organism capture and feed on
the other” (Predator Prey Relationship)
Exp. –1. Dactylaria sp. (predacious fungi)
2. Dactylella sp. (parasitic nematode)

7. 4. Parasitism – “Relationship between host and
pathogen (coiling)

8. Biocontrol Agents
1. Tricoderma
2. Aspergillus
3. Gliocladium
4. Pseudomonas
5. Bacillus
6. Dactylaria

9. Method of Application of Biological
Control Agents
1. Seed Treatment
2. Soil Treatment
3. Foliar Spray
4. Root Dip

10. Formulations
1. Pant Biocontrol Agent -1
2. Pant Biocontrol Agent -2
3. Pant Biocontrol Agent -3
4. Cingaurd
5. Sanjevani
6. Biotox

11. Mode of Biological control
1. Directly parasite pathogen & ultimately kill them
2. By way of competition for food & space
3. They can produce toxic substances which affect the pathogen
directly, by means of antibiosis
4. Direct toxic effects on pathogen by production of volatile substances
such as – Ethylene
Exp. Root knot nematode - ↑egg hatching & larval motility
5. Some components in high conc. cause direct mobility & death of larvae there by
reducing inoculum
6. Vigorous growth of the pls. - ↑ nutrition uptake

12. Diseases Managed by Biological
control
1. Sheath Blight of Rice
2. Wilt of Pulse Crops
3. Damping off of Vegetables
4. Crown Gall of Apple

13. Thank You