Eeffects of climate change on plant diseases are described here through case studies

1. Impact of climate change on
plant diseases
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2.  Introduction
 Reasons behind
 How it affect ?
 Components of Plant diseases
 Effect on interaction
 Effect on diseases management practices
 Strategies to overcome
 Conclusion
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3. What is climate?
 Climate is how the atmosphere "behaves" over
relatively long periods of time.
What is climate change?
 It refers to any change in climate over time,
whether due to natural causes or as a result of
human activities.
 Human activities like rapid industrialization
intensive agriculture, indiscriminate use of
fertilizers, deforestation and increasing use of
fossil fuels during past 150 years are considered
major factors for climate change.
Source: IPCC, 2007
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4. Impacts on climate constituents
 Global temperature rise - 1- 3.50 C .
 Global water vapor concentration rise - 6 % per 10 C
warming.
 Global precipitation rise - 2- 5 % per 1
0
C rise in
temperature.
 Atmospheric Co2 Concentration - Increased from
280 ppm in 1750 to 400 ppm in 2013.
Source: IPCC,2014
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5. 5
Tsunami Kyaar
Amezon and austrelia forest fire

6.  Climate change, and human activities
 International travel and trade
 Quickly spread pests and diseases around the world
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7.  High monsoon dependency
 2/3rd area rain dependent
 Close link between climate and water resources
Agriculture
GHG emissions
climate change
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8. 1. Natural Causes
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1) Volcanoes
2) The Earth’s tilts
3) Intensity of Solar Radiation
2. Anthropogenic Causes 1) Green House Gases
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (NO2)
Chloro floro carbons
(CFCs)
Ozone (O3)
Water Vapors (H2O)
2) Land Use Change
Deforestation
Urbanization

9. How climate change affects to plant
diseases
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10. Rising human population
Industrialization Energy use Agricultural intensification
CO2 N2O CO2 CH4 NO2
Climate change weather fluctuations
Abiotic stress in plants
New location for crop species
Altered stress signalling
Differential disease outcomes
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fig. The various factors that may impact plant–pathogen interactions via
anthropogenic changes in atmospheric composition
Source: Fones and Gurr, 2017

11.  Climatic situations may cause crop failures, shortage of yields,
reduction in quality
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Effect of climate change on components of Disease
Disease
1. Effect on
morphology and
Physiology.
2. Effect on host
resistance.
1.Physiology and
aggressiveness .
2.Survival and
Dispersal.
3. Speciation.
Host Pathogen
Environment

12. Elevated level of CO2 can increase pathogen
fecundity, leading to enhanced rate of pathogen
evolution
UV-B radiation will increase the chances of
variability in plant pathogens
Source: Chakraborty and Datta,2003
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13. 13
CLIMATE CHANGE AND PLANT
DISEASE MANAGEMENT
Stella Melugin Coakley
Department of Botany and Plant Pathology, Oregon State University, Corvallis,
Oregon 97331; e-mail: coakleys@bcc.orst.edu
Harald Scherm
Department of Plant Pathology, University of Georgia, Athens, Georgia 30602;
e-mail: scherm@uga.edu
Sukumar Chakraborty
CSIRO Tropical Agriculture, CRC for Tropical Plant Pathology, University of
Queensland, Queensland 4072 Australia; e-mail:
sukumar.chakraborty@tag.csiro.au
Key Words climate variability, epidemiological models, global warming,
host-pathogen interactions, risk and impact assessment

14. 14
Cumulative number of lesions (a) and disease severity expressed as
percent leaf area affected (b) caused by Colletotrichum gloeosporioides
on susceptible Stylosanthes scabra plants

15. fig. Disease severity (on a scale from 0 to 9) caused by
Colletotrichum gloeosporioides on susceptible Stylosanthes scabra
plants
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16.  With elevated CO2 level. pathogen will rapidly spread in host once get introduced in
plant system (Lupton et al.,1995).
 Appressoria formation of Magnaporthe grisea was noted to be significantly higher at
29°C as compared to at 22°C (Viswanath et al.,2015).
 Gradual increase in temperature shortens the period of disease cycle in stem rust of
wheat.
 High temperatures and drought stress can increase the risk of aflatoxin
contamination in the Maize-Aspergillus flavus pathosystem. High temperatures and
dry conditions favour growth, conidiation, and dispersal of A. Flavus and reduce
growth and development of maize(Fernando 2017).
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Temperature Duration
50C 20 days
100C 15 days
200C 9 days
250C 6 days

17. 1. Fungicide and bactericide efficacy may change with increased CO2,
moisture, and temperature.
2. Increase in rainfall frequency results in washing off of fungicide,
triggering more frequent applications.
3. Rate of absorption of systemic fungicides will be reduced because of
smaller stomata opening or thicken epicuticular waxes in plants grown
under higher temperature and Co2 levels.
4. Exclusion of pathogens through quarantine will become more difficult
for authorities as unexpected pathogens might appear more frequently
on imported crops.
5. Change in atmospheric composition will modify the community
structure of phyllosphere and rhizosphere micro-flora.
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18.  Climate change projections made for India
indicate an overall increase in temperature by
1– 40C and precipitation by 9–16% towards
2050s (Krishna Kumar et al., 2011).
 Different regions are expected to experience
differential change in the amount of rainfall in
the coming decades (Venkateswarlu et al., 2010)
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District wise scenario of sensitivity index to
climate change in India.
Districts Very
High
High Mediu
m
Low Very
Low
India 115 115 114 114 114
Maharashtra 12 05 03 6 7
Source: Ram Rao et al.,2015

19. Impact in humid tropical zone:
Rainfall pattern is the important factor of climate change
that influences crop diseases in this region.
Epidemic of fruit drop of sapota in Palghar district ( 2013)
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Month Rainfall Mean RH Disease
severity
June 205 % 93 - 97% 67 - 89%
July 110 %
Source: Joshi et al., 2014

20.  Extended rains in Late September- October has resulted in
increased incidence of hitherto minor diseases of rice viz. Neck
blast, Sheath rot and Grain discoloration
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Neck blast, Grain Discoloration
Sheath rot
Source: Pande and Joshi, 2013

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CASE STUDY-1

22. Inoculation growth stage of Rice Plants
Year Panicle Initiation Panicle Formation
Ambient Elevated Ambient Elevated
1998 86.88 142.88 24.25 33.75
1999 26.33 26.65 5.87 6.14
2000 17.81 24.94 7.06 9.31
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Sheath blight incidence under ambient and elevated
CO2 concentrations on rice
Year Ambient
CO2
Elevated
CO2
Ambient
CO2
Elevated
CO2
Diseased plants (%) Lesion height (%)
1999 3.2 10.1 21.5 24.5
2000 20.1 40.3 40.2 41.2

23.  Anthuriums plants exposed to temperatures greater than 31°C (87.8°F)
were more susceptible to disease than inoculated plants exposed to 26°C (78.8°F)
or lower temperatures. Effect of temperature on Anthurium was occurance of
bacterial blight (Xanthomonas axonopodis pv. dieffenbachiae) development. Plants
grown at 26°C developed few symptoms but at 31°C shows higher severe blight.
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Source: Alvarez et al. 2006

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Abiotic
factors
Temperature
Rainfall
Photoperio
d
Wind
Sunshine
hours
Physiologic
al growth
Flowering
Fruit setting
Fruit
development
Seed setting
Final
reproductive
or
vegetative
yield
High
rainfall
and
humidity
invite pests
like aphid
and
diseases
like
powdery
mildew in
most of the
seed spices
viz.,
coriander,
fenugreek,
cumin,
etc.
Source: Sharangi 2018

25.  Changes to moisture and temperature conditions have
increased the risk of Black Sigatoka by more than 44%
in Latin America and near by areas of Brazil.
 International trade and increased banana production
have also aided the spread of Black Sigatoka, which can
reduce the fruit produced by infected plants by up to
80%.
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Source: Bebber 2019

26. 1. More research is needed on phytopatho system for
important diseases with specific/combined factor (s) of
climate change.
2. Search for new resistant genes against important
pathogens which will tolerate and function under climate
change.
3. Validation of weather based disease forecasting models.
4. Evaluation of new and safe molecules which retain their
efficacy against specific factor of climate change.
5. Evaluation of efficient bio- control agents which will suit
the modified atmosphere due to climate change.
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27.  CONCLUSION:
 Need to come in action for understanding
epidemiology, pathogen and Host behaviour in
relation to climate change and its impact on
cultivation, production of food.
 Disturb food cycle/chain of nature may disturbs
human life without any intimation.
 Modified environment has profound impact on
disease management strategies.
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28. Come Forward..
Join hands..
Save Agriculture..
to sustain ourselves..
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29. Thank you !
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