Principles Plant Disease Management

Reshma Ranjan M.Sc.(PBG)

Plant Breeding And Genetics

IntroductionDisease- A diseases is the impairment of the normal

physiological functioning of a plant or plant part, caused

by the continued irritation of a primary factor or factors.

Loss due to disease range from: A few to 30 %

In case of sever infection: 100% crop failure

Striking effect of disease

Elimination of some

promising Variety

Kalyan Sona and Janak Variety in

wheat

How A disease Develop…….

Development of any disease

depends on a close interaction

among three diverse factors:

• The Host

• The pathogen

• The environment

Measures taken to prevent incidence of a disease, reduce the amount of inoculum that initiates the spreads of disease and finally minimises the loss caused by the disease have traditionally being called as control measures.

Plant disease management is the eminent process in crop production.

A disease can be managed by eliminating interaction between ◦ A susceptible host◦ A virulent pathogen◦ In suitable environmental condition

What is Control Measures……

PRINCIPLES OF PLANT DISEASE MANAGEMENT

1) AVOIDANCE2) EXCLUSION3) ERADICATION4) PROTECTION5) RESISTANT VARIETIES6) THERAPY

H. H. Whetzel included four general disease control principles, Exclusion, Eradication, Protection, Resistance

AvoidanceAvoiding disease by altering planting time,

or planting in areas where inoculum is ineffective due to environmental condition or rare or absent.

Avoidance can be carried out by:-

Choice of geographical areas

Selection of field

Selection of seed and planting material

Choice of time of showing

Disease escaping varieties

Modification of cultural practices

Exclusion

Preventing the inoculum from entering or establishing in the field or area where it does not exist.

Seed treatmentInspectionCertificationQuarantine (Federal or State)

Cleaned farm equipmentCleaning farm equipment

Eradication

This principle aims at eliminating a pathogen after it is introduced into an area but before it has become well established or widely spread.

It can be applied to individual plants, seed lots, fields or regions It is generally not effective over large

geographic areas

Eradiation can be done by……

Destroying weeds that are reservoirs of various pathogens or insect vectors of disease,

Biological control of plant pathogenCrop rotationSoil treatmentHeat and chemical treatment

Elimination of potato cull piles

Weed Control

Crop Rotation

Soil Treatment

Burning of infected residues crop

Propane flaming

Protection

Preventing infection by creating a chemical toxic barrier between the plant surface and pathogens.

Chemical treatmentChemical control of insect vectorModification of environment or environment conditionModification of host nutrition

Protection can be done by……

Bananas are covered with plastic sleeves

Raised planting beds Ground sprayers

Resistant Varieties

Preventing infection or reducing effect of infection by managing the host through improvement of resistance in it by genetic manipulation or by chemotherapy.

Selection and hybridisation of disease resistance

Mutation for disease resistance

Susceptible and resistant plant to papaya ringspot virus

Susceptible and resistant plant

Therapy of disease plant

Reducing severity of disease in an infected individual by chemicals.

ChemotherapyTree SurgeryHeat Therapy

Thank You