Biotic and abiotic factors helps in studying the diseases, yield, amount of organic matter which impact the plant development

1. Department of sericulture
Brief presentation on influence of biotic and abiotic
factors on the incidence of plants diseases
Semester – I : Paper – II
Supervised by, Presented by,
Kuntamalla Sujatha Mam Akhila Kesupaka
Faculty of Sericulture. M.Sc Sericulture
Batch: 2023 – 2025

2. Introduction
● It is well known that for occurrence of any disease three critical factors such
as vulnerable host, virlulent pathogen and favourable environmental
conditions are very much essential.
● This type of relationship is called disease Triangle.
● If anyone component from the triangle exist it exist the degree of disease
severity.
● Epidemology is the study of biotic and diabetic factors which are influencing
the outbreak of diseases its insect intensity and epidemics.

3. Biotic factors
● All living organisms that which cause diseases to Mulberry plant are called
biotic factors.
● Example: Bacteria, Virus, fungus, Mycoplasm and Nematodes.
● Biotic factors causing Mulberry diseases are the pathogens or
microorganisms prevalent in nature

4. Fungi
Disease Name
● Leaf spot
● Leaf Rust
● Powdery mildew
● Leaf blight
Pathogen
● Cercospora moricola
● Cerotelium fici
● Phyllactinia corylea
● Alternaria alternata
● A fungi mostly causes foliar diseases in mulberry
● Major foliar diseases caused by fungus in mulberry are
as under

5. Bacteria
Bacteria mostly causes foliar diseases but it also effect root and stem
portion
Disease Name Pathogen name
Bacterial Wilt Pseudomonas solanacearum
Bacterial leaf blight pseudomonas syringae
Bacterial leaf spot Xanthomonas campestris

6. 3.Virus
It is also a foliar disease in mulberry
1. Mosaic disease
2. Yellow net vein disease
3. Mulberry ring spot
4. Mulberry latent virus
5. Mulberry Mosaic dwarf
6. Mulberry dwarf

7. 4.Mycoplasma
● It affects plant height in mulberry
Dwarf disease

8. 5.Nematode
● It mostly effects root system
● Most of the diseases caused by meloidogynemali, melodogyne hapia,
melodogyne arenaria and melodogyne incognita
Disease name
● Root knot
Pathogen
Melodogyne incognita

9. 2.Abiotic factors
All non living organisms which cause diseases to plants are known as Abiotic
factors
Ex. Humidity, Temperature, wind and light, soil, soil ph etc…
● Development of any prasitic diseases is critically development on the life
cycle of the pathogen
● Environmental conditions affect the life cycle of both the host and pathogen.
● There are various environmental factors which are directly affecting the
pathogens in transporting from one plant to another plant.
● The various abiotic factors influencing Mulberry diseases.

10. Temperature
● Temperature has a significant effect on the development of disease
● At lower temperature the disease severity of mulberry is observed less. which
at high temperature.
● Severily become more.
● The temperature below optimum level delays the germination of pathogen
spores, germitube growth, pathogen multiplication in host and rate of spore
production.
● Some diseases are several at low temperature.
● Species like fusarium, Colletotrichum and pseudomonas are favoured by high
temperature, especially in tropical and sub tropical conditions
● In case of cercospora moricola causing leaf spot in mulberry at temperature
of 24-26’c is favourable.

11. Relative humidity
● Moisture like temperature moisture place and important role in development
of diseases
● Moisturi scene as water on plant surface I don't the roots and also as
relatively humidity
● Moisur is an important factor for activation of bacterial fungal and Limited
growth and development
● Water is essential to activate certain enzymatic activities which initiate other
internal chemical changes and increase the volume of germinating spores
● many bacterial and fungal diseases Mulberry or favoured by high moisture or
relative humidity
● several fungi reply high immidity for release of sporas per germination

12. Wind and Light
● the role of wind in disease development is mainly dissemination of pathogens
pores from one plan to another plant as well as one place to another place
● wind becomes more important in diseases development when it is
accompanied by rain
● sports of Circus pura mokala are produced by dissolution by of Gummy
substance produced by the fungus
● rain helps in the release of bacteria from infected tissues which are them
carried by wind to Healthy plants to cause infection
● Krishna plants by wind blown sports is influenced by the quality of sports
produced at the source
● vinasha causes injurious to plants surface which help pathogens to cause
infection

13. Soil pH
● soil pH also place a vital role in the occurrence and severely of soil brown
this is like root Rot and root knot
● development of several diseases caused by root invading organisms is
affected by pH of soil hi so I'll phrase the development of some fungi and
bacteria like fusarium and streptomyces

14. Soils
● soils of Mulberry field have to maintain the Mulberry plants for substance
maximum activity of quality leaves
● the essential major and minor plan nutrients
● oxygen for root respiration
● mechanical support or encourage and as a storehouse for water
● the soil quality has an influence not only on the yield of Mulberry leaves
● the soil should be deep fertile well drained clayey loam to loam in texture able
poros and with good moisture holding capacity

15. Atmospheric humidity
● humidity range of 65 to 80% is considered ideal for one growth
● under rain fed conditions due to higher moisture in soil and high atmosphere
humidity the quality of leaf produced during the rainy season is better than the
leaf produced during other seasons

16. Atmospheric temperature
● an atmosphere temperature ranking from 24 degree celsius to 28 degree
celsius is found to be optimum for good growth of Mulberry
● growth and supporting of birds cannot be obtained at temperature below 13
degree Celsius and about 30 degree Celsius
● in temperate climate Mulberry starts separating in Spring when the
temperature through reaches 30 degree Celsius and continuous to grow up to
autum
● the plants remain dominant during November to March
● growth of Mulberry is continuous throughout the year

17. Effects of air pollution
● air pollution refers to the release into the atmosphere of materials in
concentrations that are harmful to man other animals and plants
● major sources of air pollution are fossils fuels and industries
● air pollution is another abiotic source for plant disease
● We all know that without CO2 the photosynthesis could not occur but when the
limit CO2 concentration break there occur various types of disorder in plant life
● the relatively closed environment of growth Chambers facilitates CO2 enrichment
studies with plants and several commercial growth chamber manufactures will
provide CO2 control capabilities upon request
● the symptoms of leaf rolling or deformation and chlorosis or chloric molting of
leaves are caused by air pollution
● recent studies have also shown that high CO2 can increase endogenous ethylene
production in some plants which may contribute to the injurious effects from high
CO2 levels

18. Thank you