Introduction METHODS USED IN PLANT DISEASE MANAGEMENT Cultural method Biological control method Breeding method for disease resistance TYPES OF RESISTANCE CONCEPT OF RESISTANCE

1. WELCOME
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2. FUTURE TRENDS IN PLANT DISEASES
PRESENTED BY
NAVEED UR REHMAN
BS-7TH, MICROBIOLOGY

3. • Contents
1. Introduction
2. METHODS USED IN PLANT DISEASE MANAGEMENT
I. Cultural method
II. Biological control method
III. Breeding method for disease resistance
3. TYPES OF RESISTANCE
4. CONCEPT OF RESISTANCE
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4. FUTURE TRENDS IN PLANT DISEASES
1. INTRODUCTION:
• Plant disease control is eminent process in crop yielding without complete or partial
eradication of pathogen
• Control measures of disease cannot get good crop yield results without proper control
amendments of disease or pathogen
Fig. 1: Fruits are infected by pathogenPLANT MICROBIOLOGY
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5. FUTURE TRENDS IN PLANT DISEASES
1. INTRODUCTION:
• The major aspect of plant disease control is to “eliminate or eradicate the pathogen
from plant / crop, and control the loss of crop yield
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6. FUTURE TRENDS IN PLANT DISEASES
2. METHODS USED IN PLANT DISEASE MANAGEMENT
I. AVOIDENCE OF PATHOGENS
II. BIOLOGICAL CONTROL METHODS
III. BREEDING METHODS FOR DISEASE RESISTANCE
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7. FUTURE TRENDS IN PLANT DISEASES
I. AVOIDENCE OF PATHOGEN
• Diseases can be prevented by a proper selection of the land or field, choice of time of
sowing, selection of varieties, seed and plant stock and by modification of cultural
practices
• The aim of these measures is to enable the host to avoid contact with the pathogen
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8. FUTURE TRENDS IN PLANT DISEASES
i. PROPER SELECTION OF GEOGRAPHICAL AREA
• Many fungal & bacterial diseases are more severe in wet areas than in dry areas, crop which
are susceptible to these diseases, if grown in wet areas are likely to be effected by plant
pathogens
• For example, smut disease of bajra caused by Tolyposporium pencillariae
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9. FUTURE TRENDS IN PLANT DISEASES
ii. SELECTION OF FIELD
• The selection of suitable area or field for cultivation is very important from the point
of view of better yield's, as well as protection of the crop from the ravages in the case
of many soil borne pathogens
• Hence it is advisable not to grow in the same field, where there is high incidence of
disease appearing, due to build-up of inoculum potential
• For example, the drainage conditions of the field are also important , low lying,
water logged fields favor such diseases as red rot of sugarcane and downy mildews
of bajra
• In case of fruit orchards the selection of suitable site is very important
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10. FUTURE TRENDS IN PLANT DISEASES
iii. CHOICE OF TIME OF
SOWING
• Pathogens are able to infect susceptible
plants only under certain environmental
conditions
• For example, Rhizoctina root rot of
gram is severe if gram is sown
immediately after the rains, due to the
pathogen develops rapidly under high
temperate and moisture conditions
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Fig. 2: Time of sowing (Google image)

11. FUTURE TRENDS IN PLANT DISEASES
iv. DISEASE ESCAPING VARITIES
• Certain varieties escape the onslaught of the pathogen and resist the attack due to
their inherent characteristic's
• For example, maturing varieties of wheat or pea escape damage due to Puccinia
graminis Tritici and Esiphe polygoni respectively.
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12. FUTURE TRENDS IN PLANT DISEASES
v. SELECTION OF SEED
AND PLANTING STOCK
• Since many plants propagate by
vegetative parts, the selection of
diseases free planting material, forms a
very important control measures
• The planting of disease-free fields is
often an important control measures for
certain diseases such as red rot of sugar
cane and black scruff of potato etc
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Fig. 3: Selection of seed and plant stock

13. II. BIOLOGICAL CONTROL
METHODS
• The term biological control clearly
implies control of a disease through
some biological agency
• The term biological agency, means a
living micro organism or macro
organism other than the diseased or
damaged plant acting as host and the
pathogen or pest causing the disease or
damage Fig. 4: Biological control (Google image)
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14. FUTURE TRENDS IN PLANT DISEASES
II. BIOLOGICAL CONTROL METHODS
• According to Garrett (1965) “ biological control of plant disease may be defined as
• Any condition or practice whereby survival or activity of a pathogen is reduced
through the agency of any other living organism (except man himself)
• The result that there is a reduction in the incidence of the disease caused by the
pathogen
• For example, Trichoderma viride, a common saprophytic fungus, is able to parasitize
the mycelia of other fungi.
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15. FUTURE TRENDS IN PLANT DISEASES
III. BREEDING FOR DISEASE RESISTANCE
• The use of disease resistant varieties for controlling plant diseases has been termed
the “painless method” because it does not cost the farmer anything
• The use of resistant cultivars and hybrids has several other advantages it eliminates
the hazards to human health and wild life which is caused by large scale use of
dangerous fungicides and pesticides
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16. FUTURE TRENDS IN PLANT DISEASES
III. BREEDING FOR DISEASE RESISTANCE
• It also reduces pollution which results from the use of poisonous chemicals and their
residues, resistant crop varieties check epidemics of pathogens and pests
• It help to maintain the biological balance environment
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17. FUTURE TRENDS IN PLANT DISEASES
3. TYPES OF RESISTANCE
• Plant pathologists commonly divide resistance into monogenic, Polygenic, and
Oligogenic according to whether the resistance is governed by one or many genes, or
a few genes resistance can be described as genetic, mechanical or epidemiological
• Oligogenic resistance is determined by 2 to several genes
• Polygenic resistance involves many genes which are more difficult to analyze and
which are known to be included in a large no of diseases such as cotton wilt
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18. FUTURE TRENDS IN PLANT DISEASES
3. TYPES OF RESISTANCE
• FEW STEPS INCLUDED
• Extra chromosomal inheritance
• Gene interaction
• Modifier genes
• Reversal of dominance
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19. FUTURE TRENDS IN PLANT DISEASES
4. Concept of vertical and horizontal resistance
• Methods of selection of resistant on geno types
• Selection from existing crops
• 1. Selection from crops that escape damage in infected fields
• 2. Pure line selection
• 3. Plant introduction
• 4. Hybridization
• 5. Selection from wild verities
• 6. Induced mutations
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20. THANK YOU
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21. ANY QUESTION ?
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