WELCOMEWELCOME
“IMPACT OF CLIMATE CHANGE ON PLANT DISEASES”
OUTLINE OF SEMINAR
Climate change
Causes of climate change
Forms of climate change
Plant diseases and climate change
Impact climate change factors on plant
Impact on plant disease management
Response to climate change
Conclusion
44
The Earth is surrounded by a thick layer of gases which keeps the planet warm and allows plants, animals and microbes to live. These gases work like a blanket.
Without this blanket the Earth would be much colder and less suitable for life.
Weather is the day-to-day conditions of a particular place.
The climate is the common, average weather conditions at a particular place over a long period of time.
What is climate change?
Change in climate over time, either due to natural variability or as a result of human activity
IPCC-2007
FORMS OF CLIMATE CHANGE
Indian drought -2014 due to El nino effect
Forest fire in russia-2010
7
SOURCE: www.ipcc-data.org SOURCE: www.ipcc-data.org
• International Agencies working to curb climate change
• IPCC Intergovernmental Panel on Climate change
• UNFCC United Nations Framework Convention on Climate Change
• WMO World Meteorological Organization
• UNEP United Nations Environment Programme
10
Causes of climate change
1.High CO2 in the atmosphere
2. Increase in Temperature Maximum and minimum temperature
3.Variation in rainfall patternNo. of rainy days/ shift in seasonAmount and distribution
4.Solar radiation Day length5.Drought6.Floods
Major Parameters of Climate change
12
When sunlight reaches Earth's surface some is absorbed and warms the
earth and most of the rest is radiated back to the atmosphere at a longer
wavelength than the sun light. Some of these longer wavelengths are
absorbed by greenhouse gases in the atmosphere before they are lost to
space. The absorption of this long wave radiant energy warms the
atmosphere. These greenhouse gases act like a mirror and reflect back to
the Earth some of the heat energy which would otherwise be lost to
space. The reflecting back of heat energy by the atmosphere is called the
"Greenhouse Effect".
14
Global warming is the increase in the average measured temperature of the Earth's near-surface air and oceans since the mid-twentieth century, and its projected continuation..
IPCC, (2007)
GLOBAL WARMINGGLOBAL WARMING
Global temperature
rises
Effects
Temperature rise in 1˚C Thousand of home flooded
Temperature rise in 2˚C Glacier disappear
Temperature rise in 3˚C Amazon drains out ,snowcaps on alps disappears.
Temperature rise in 4˚C Ocean rises flooding populated area of Bangladesh washed away.
Temperature rise in 5˚C Desertification river dry up climate refugee conflict over water, food and space
Temperature:
Each pathogen has an optimum temperature for growth. In
addition, different growth stages of the fungus, such as the
production of spores, their germination, and the growth of the
mycelium, may have slightly different optimum temperatures.
Relative humidity :
Relative humidity is very critical in fungal spore germination
and the development of storage rots.
Environmental factors affecting disease development
High humidity favours development of the great majority of
leaf and fruit diseases caused by fungi and bacteria.
Soil moisture:
High or low soil moisture may be a limiting factor in the
development of certain root rot diseases.
High soil-moisture levels favour development of destructive
water mold fungi, such as species of Aphanomyces, Pythium,
and Phytophthora.
Effect of increased CO2 concentration on pathogens
An increase in CO2 levels may encourage the production of plant
biomass.
Concentration of carbohydrates in the host tissue promotes the
development of biotrophic fungi such as rust.
Chakraborty et al. (2002)
Altered the expression of three soybean diseases, namely downy mildew
(Peronospora manshurica), brown spots (Septoria glycines) and sudden death
syndrome (Fusarium virguliforme) .
Higher CO2 can increase the fertility of fungi, which may produce more
spores,
At the same time, plants grown in high carbon dioxide environments also
close their stomata, pores in the leaves that allow the plant to take in carbon
dioxide and release oxygen, more often. Because plant pathogens often
enter the plant through the stomata, the more frequent closing of the
stomata may help prevent some pathogens from getting into the plant.
Changes brought by high CO2 concentration like reduced stomatal
density .
The reduction in stomatal opening can inhibit stomata-invading
pathogens, such as rusts, downy mildews.
Manning & Tiedemann (1995)
Effect of increase in temperature
Changes in temperature and precipitation alter the growth stage,
development rate and pathogenicity of infectious agents,
Chakraborty, S. et al.,(1998)
Climate change is also reported to cause a shift in the geographical
distribution of host pathogens.
Mboup, M et al, (2012).
A change in temperature affect the physiology and resistance of the
host plant.
Higher risk of dry root rot has been reported in Fusarium wilt
chickpea-resistant varieties in those years when the temperature
exceed 33 0 C .
Bacterial diseases such as Ralstonia solanacearum, Acidovorax
avenae and Burkholderia glumea.
Drought stress has been found to affect the incidence and
severity of viruses such as Maize dwarf mosaic virus and Beet
yellows virus.
Clover, et al (1999)
Early outbreak or increases in the intensity of potato late
blight (Phytophthora infestans) under climate change in central
Europe.
Kocmánková et al (2009)
IMPACT ON DISEASE MANAGEMENT
HOST RESISTANCE
Cultivar resistance to pathogens may become less effective because of
increased static and dynamic defences from changes in physiology,
nutritional status, and water availability .
Durability of resistance may be threatened, however, if the number of
infection cycles within a growing season increases because of one or more of
the following factors: increased fecundity, more pathogen generations per
season, or a more suitable microclimate for disease development. This may
lead to more rapid evolution of aggressive pathogen races.
CHEMICAL CONTROL Climate change could affect the efficacy of crop protection
chemicals.
Changes in temperature and precipitation may alter the
dynamics of fungicide residues on the crop foliage. Globally,
climate change models project an increase in the frequency of
intense rainfall events which could result in increased fungicide
wash-off and reduced control.
Response to climate changeResponse to climate change
Better understanding of gene expression in plants and
pathogens in response to climatic factors.
Integrated studies of host and pathogen responses, as well
as communities of soil and plant associated microbes.
Multifactor studies of climate change effects.
Long-term, large-scale records of pathogen and host
distributions.
Conclusions : Plant disease has a major impact on agricultural and natural
systems.
Current strategies for management need to be maintained and
improved, even if the climate did not change.
Climate change will increase some disease risks and decrease
others.
Systems may change more rapidly than in the past, requiring more
research and policy attention.
Come Forward..
Join hands..Save Agriculture..to sustain ourselves..
Thank You !
Top Related