Principles of Disease Control CHAPTER 5

Avoidance/Exclusion Eradication Protection Resistant

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

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.

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.

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

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

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

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

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

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

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.

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

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.