This document discusses principles of disease control in agricultural microbiology. It outlines four main principles: 1) Avoidance/Exclusion to prevent import and spread of pathogens, 2) Eradiation to reduce pathogen amounts, 3) Protection to directly protect plants from infection, and 4) Resistant varieties that hinder pathogen development. Specific control methods are described under each principle, including quarantine, sanitation, crop rotation, biological and chemical controls, and genetic engineering to develop resistant varieties.

1. MIC 319
FUNDAMENTALS OF
AGRICULTURAL
MICROBIOLOGY
CHAPTER 5
PRINCIPLES OF DISEASE CONTROL
BY
SITI NORAZURA JAMAL
03 006/ 06 483 2132
norazura6775@ns.uitm.edu.my

2. Outline
Principles of disease control
1) Avoidance/Exclusion
2) Eradiation
3) Protection
4) Resistant

3. 1) Avoidance/Exclusion

4. Avoidance/Exclusion
To prevent the import and spread of
plant pathogens into areas from
which they are absent
1) Quarantine and Inspection
2) Evasion or avoidance of pathogen
3) Use of pathogen free propagating
material

5. 1) Quarantine and
Inspection
Regulations controlling the import and export of
plants to prevent spread of disease and pest
The Agricultural Pests and Noxious Plants
(Import/Export) Regulations 1981 govern
the import of plants, plants products, insects
and microorganisms into Malaysia
Each state is responsible for enforcing
quarantine regulations to prevent the spread of
pests and diseases within the state.

6. 1) Quarantine and
Inspection
Inspection of Plants/Insects at Legal
Entry Checkpoint.
All planting materials, plant product, insects
etc which is prohibited materials subjected
to inspection at the entry checkpoint and if
found infested or diseases shall be treated,
quarantine or destroyed
Air (KLIA, Subang Airport, Senai Airport)
Road (JB, Padang Besar, Chanloon, Rantau
Panjang)

7. 2. Evasion or avoidance of
pathogen
Grow the plant in the area or
environment that unsuitable for the
growth of pathogen.
Plant a susceptible crop at a great
distance from other fields containing
possible disease.

8. 3. Use of pathogen free
propagating material
Use a pathogen- free seed
Growing the crop in an area that
Free or isolated from the pathogen
Not suitable for the vector of the
pathogen

9. 2) Eradiation

10. Eradiation
To reduce amount of pathogen
present in an area, a plant or plant
part
1) Host eradication
2) Sanitation
3) Crop rotation

11. 1) Host eradication
Remove or burn all of the infected
host plant
Remove alternate host for the
pathogen

12. 2) Sanitation
Wash hands before handling certain
kinds of plant such as tomato
Frequently disinfesting knives used
to cut propagative stock such as
potato tubers

13. 3) Crop rotation
The practice of growing a series of
dissimilar types of crops in the same
area in sequential seasons
Crop rotation also seeks to balance
the fertility demands of various crops
to avoid excessive depletion of soil
nutrients

14. 3) Protection

15. Protection
Protect the plant directly from any
infection that are likely to arrive.
1) Biological control
2) Chemical control

16. 1) Biological control
The process to reduce or control the
pest level by using another microorganism
Use antagonistic microorganism –
microorganism that antagonist to the
pathogen
The microorganism will destroy and
inhibit the growth of pathogen.
Environmentally friendly method.

17. 2) Chemical control
Application of chemical compounds
that are toxic to the pathogen
Inhibit germination, multiplication
and growth of the pathogen.

18. 4) Resistant

19. Resistant
Possessing qualities that hinder the
development of a given pathogen
Use genetic engineering technique
Insert the plants with genes that
code for production of enzymes or
toxin that could interfere pathogen
infection.