1. Principles of Disease Control
CHAPTER 5

2. Avoidance/Exclusion
Eradication
Protection
Resistant

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

4. 1. Quarantine and Inspection
Regulations controlling the import and export of plants to prevent spread of disease and pest
Plant quarantine centre – airport, port harbor and state boundary town.

5. 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.

6. 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

7. Eradication
To reduce amount of pathogen present in an area, a plant or plant part
Host eradication
Sanitation
Crop rotation

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

9. 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

10. 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

11. Protection
Protect the plant directly from any infection that are likely to arrive.
Biological control
Chemical control

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

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

14. 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.