Scenario of disease under climate change

1
Welcome
2
SCENARIO OF DISEASES UNDER CLIMATE CHANGE
SITUATION AND FUTURE CHALLENGES IN
INDIA   DEPARTMENT OF PLANT PATHOLOGY COLLEGE
OF AGRICULTURE, BIKANER
3
Content

• Introduction
• Development of disease in plant
• Change in global climate
• How climate change affect plant diseases?
• Climate change and its impact on plant diseases
• Effects of climate change on host plant
• Effects of climate change on pathogens
• Effects of climate change on plant disease
  management
• Future challenges in India
• Conclusion
• Future thrust

4
Introduction
5
What is Climate Change?

• It refers to any change in climate over time,
  whether due to natural variability or as a result
  of human activity (IPCC, 2007).
• Climate change refers to a change of climate that
  is attributed directly or indirectly by human
  activity that alters the composition of the
  global atmosphere and climate variability
  observed over comparable time periods.
• Climate encompasses the long-run pattern of
  numerous meteorological factors (e.g.
  Temperature, humidity, atmospheric pressure,
  wind, rainfall, sunshine etc.) in a given
  location or larger region. (Gutierrez et al.
  2010)

6

• Plant diseases are a significant reduce the
  production of more than 25 crops that stand
  between the rapidly expanding world population
  and starvation.
• World-wide losses from diseases range from 9 to
  16 in rice, wheat, barley, maize, potato,
  soybean, cotton and coffee. In USA alone,
  fungicides worth over US 11.2 billion for
  control diseases. (Agrios, 2005)
• Plant diseases will respond to climate change,
  through a number of interactions, take place
  among host, pathogen, potential vectors.

7

• The Great Irish Hunger is one striking example of
  the impact of plant disease In 1845 more than a
  quarter million Irish people starved as the
  result of an epidemic of potato late blight.

• Plant diseases continue to cause serious problems
  in global food production. Currently more than
  800 million people do not have adequate food and
  at least 14 of global food production is reduced
  due to plant diseases (Agrios, 2005).

8

9

• Fungi
• Bacteria
• Virus
• Mycoplasmas
• Nematodes
• Parasitic Plant

Plant Pathogen
The very different life histories of this diverse
group of organisms and their different
interactions with host plants produce a wide
range of responses to environmental factors.
For example Fungal pathogens are often strongly
dependent on humidity or dew for plant
infection. viruses may be present in hosts while
symptom expression is dependent on temperature.

10
Year Disease host Event
1943 (West Bengal) Brown leaf spot (Helminthosporium oryzae) Rice Favourable climatic condition of introduced variety TN-1.
1971 (Karnataka) Tobacco streak virus Sunflower Due to severe drought condition than this virus shifted to ground nut in A.P. cause severe loss during 2002.
1978 (India) Fruit rot (Phytophthora meadii) Arecanut Changes in rainfall pattern, temperature and humidity (Prolonged period of season with total rainfall 5088.6 mm).
2006 (A.P.) chilli veinal mottle virus and cucumber mosaic virus Chilli , Cucumber Heavy flood
11
Development of Disease in Plant
12
Essential factors for disease development
Favorable
Environment
Environment
Time
Virulent
Susceptible
Host
Pathogen
Disease
13
Potential outcome from the changes
Interaction among factors that causes the
disease intensity
Host change Variety Cultural practices Chemical
practices
Pathogen change Genetic shift Movement
Reduced disease intensity
Major Epidemics
Host
Pathogen
Changes favorable to disease in one or two factor
Environment
Climate change Temperature CO2
content Precipitation Cloud cover
Development of disease
14
Climate change affects Disease pyramid
15
Temperature Effects on Crop Yield Several
Major Crops
Crop T opt OC T max OC Yield at T opt, t/ha Yield at 28 OC, t/ha Yield at 37OC, t/ha Decrease
Rice 25 36 7.55 6.31 2.93 54
Soybean 28 39 3.41 3.41 3.06 10
Dry bean 22 32 2.87 1.39 0.00 100
Peanut 25 40 3.38 3.22 2.58 20
Grain Sorghum 26 35 12.24 11.75 6.95 41
(Rao, 2009)
CRIDA, Hyderabad
16
Change in Global Climate
17

• A portion of the radiation reaching to earths
  surface which is scattered or reflected by
  clouds, aerosols, dust and other particles.
• Radiation reaching the planet is partly
  absorbed, causing the Earth to emit thermal
  radiation and part of the radiation is reflected
  back to the atmosphere.
• Water vapour and radioactively active CO2, CH4,
  N2O and O3 etc. partly trap the reflected
  radiation to warm the surface temperature, a
  natural phenomenon known as the Greenhouse
  Effect.

18
Radiation reflected back to space
Reflected radiation which keeps earth livable
and warm
Sun rays
19
Radiation reflected back to space
Radiation gets trapped because of thickening of
Atmospheric layer
Green house effect
Sun rays
Green house effect
20
Causes of climate change
Natural Causes
Anthropogenic Causes

1. Continental drift
2. Volcanoes
3. The Earths Tilts
4. Ocean Currents
5. Intensity of Solar Radiation

1) Green Houses Gases Carbon dioxide
(CO2) Methane (CH4) Nitrous oxide
(NO2) Chloro floro carbons (CFCs)
Ozone (O3) Water Vapors (H2O) 2) Land Use
Change Deforestation Urbanization
21
Except one all other are MAN-MADE EMISSIONS
22
2005
1979
23
Increase in Global mean temperature
Global mean temperatures have increased by 0.74oC
during last 100 years. The rate has become faster
in recent years
Anon, 2007
24
Projection of CO2 and global mean temperature
Increase in O3 conc.
Increase in CO2 conc.
20-30 nl L-1
60 nl L-1
25
How Climate Change affect Plant Diseases?
Mechanism of Climate Change on diseases
26
Elevated CO2

• Affect physiology of host pathogen interaction
• Increase in canopy density (gtfoliar diseases)
• Increase in moisture stress (gtdry root rot)
• Increase in severity/fecundity ( gtanthracnose)

27

• In soybean, elevated concentration of CO2 and O3
  altered the expression of three soybean diseases,
  namely downy mildew (Peronospora manshurica),
  brown spots (Septoria glycines) and sudden death
  syndrome (Fusarium virguliforme.
• High levels of CO2 alone or in combination with
  high concentration of O3, increased the severity
  of Septoria leaf spots.
• Effect of elevated concentrations of CO2 has also
  been evaluated on two important diseases of rice,
  namely blast (Pyricularia oryzae) and sheath
  blight (Rhizoctonia solani) and rice plants were
  found more susceptible to injury.
• The severity of downy mildew damage was
  significantly reduced at high levels of CO2
• Changes brought by high CO2 concentration like
  reduced stomatal density, production of papillae
  and accumulation of silicon at the sites of
  appressorial penetration and changed leaf
  chemistry increased resistance to powdery mildew
  (Blumeria graminis) in barley.

28
Temperature and moisture

• Increased host susceptibility
• Rust reaction of wheat varieties with the stem
  rust resistance gene Sr15 can change from
  resistant at 15OC to nearly fully-susceptible at
  20OC
• Phytophthora on Pigeonpea, Soyabean
• Rust on groundnut
• More rapid/new development of pathogen
• Pathogens on chickpea, groundnut
• UG 99 stem rust of wheat
• Rhizoctonia in chickpea
• More rapid vector development
• Vector of viral diseases of rice
• Vector (Toxoptera sp.) of Citrus tristeza virus

29

• Increased over summering/overwintering of
  pathogen/vector
• Barley Yellow dwarf
• Oospore of sunflower downy mildew
• Chlamydospore of pigeonpea wilt
• Charcoal rot of sorghum
• Increased pathogen transmission
• Fusarium spp. in Chickpea, Pigeonpea
• New diseases/minor diseases can become major
• False Smut Rice
• Virulent forms of pathogens
• Vulnerability of present day host cultivars

30

• There are indications of increased aggressiveness
  at higher temperatures of stripe rust isolates
  (Puccinia striiformis), suggesting that rust
  fungi can adapt to and benefit from higher
  temperatures.
• Higher risk of dry root rot has been reported in
  Fusarium wilt chickpea-resistant varieties in
  those years when the temperature exceed 330C.
• Temperature sensitivity to resistance has been
  reported for leaf rust (Puccinia recondita) in
  wheat, broomrape (Orobanche cumana) in sunflower,
  black shank (Phytophthora nicotianae) in tobacco
  and bacterial blight (Xanthomonas oryzae pv.
  oryzae) in rice.
• Drought stress has been found to affect the
  incidence and severity of viruses such as Maize
  dwarf mosaic virus and Beet yellows virus.

31
Major impact on air borne pathogens
EVENT EFFECT
Rains floods Increased frequency of attacks
Storms Long distance migration of spores
Warming Overwintering of pathogen More generations/season Prolonged contact with host
32
Effects of Climate Change on Host Plant
33
Elevated CO2
Change in plant structure

• Plant organs may increase in size which enhanced
  photosynthesis and increased water use efficiency
  by that many foliar pathogens benefit from denser
  plant growth resulting more humid microclimate.
• It favours the pathogen to interact with the
  hosts.

34
Elevated Temperature

• When high-temperature stress is developed, plant
  responses may be similar to those induced by
  water stress, with symptoms expressed as
• Wilting,
• Leaf burn,
• Leaf folding,
• Abscission,
• Physiological responses
• RNA metabolism and protein synthesis,
• Enzymes
• Iso enzymes
• Plant growth hormones
• these changes will certainly affect
  susceptibility to pathogens.

35
Elevated Ozone

• Change the structure of leaf surfaces
• Altering the physical topography
• The chemical composition of surfaces, including
  the structure of epicuticular wax.

• These changes in leaf structure may alter leaf
  surface properties such as leaf wettability and
  the ability of leaves to retain solutes.
• All influencing the ability of pathogens to
  attach to leaf surfaces which enhance attacks on
  plants by necrotrophic fungi.

36
Effects of Climate Change on Pathogen
37
(No Transcript)
38
Free air enrichment (FACE) apparatus

• FACE experiments allow for the study of elevated
  atmospheric CO2 on agricultural crops, forest
  trees and plant ecosystems grown under natural
  conditions.
• FACE facilities have been developed and deployed
  from those on the scale of 12m for low-stature
  crops or ecosystems to those of 1020m diameter
  for field crop evaluation to those for young-to
  medium-aged forest stands and finally to mature
  trees of basically any size.
• FACE research in some Agricultural crops
• SoyFACE, Illinois, USA
• Rice (Rice FACE, Shizukuishi, Japan)
• Grapes (Rapolano Mid FACE, Chianti Region, Italy)
  

39
Free air enrichment (FACE) apparatus used for
pure CO2 injection in the field
40
Ozone impact on leaf Surface

Control
Elevated O3
41
Studied the number of leaf blast lesions per
plant grown in ambient and elevated CO2
conditions in rice
Inoculation growth stage of Rice Plants Inoculation growth stage of Rice Plants Inoculation growth stage of Rice Plants Inoculation growth stage of Rice Plants Inoculation growth stage of Rice Plants
Year Panicle Initiation Panicle Initiation Panicle Formation Panicle Formation
Year 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
Kobayashi et al. 2006
Japan
42
Sheath blight incidence under ambient and
elevated CO2 concentrations on rice
  Year   N Ambient CO2 Elevated CO2 Ambient CO2 Elevated CO2
  Year   N Diseased plants () Diseased plants () Lesion height () Lesion height ()
1999 High 3.2 10.1 21.5 24.5
2000 High 20.1 40.3 41.2 41.2
2000 Low 10.3 13.4 33.3 36.4
Kobayashi et al. 2006
43
Siderophore production by Pseudomonas spp. under
elevated CO2
Anon, 2010
43
44
Impact of elevated CO2 on pathogenicity of major
soil-borne phytopathogens
CRIDA, Hyderabad
Anon, 2010
45
Effect of increased CO2 concentrations on
pathogens.
Study Effect Author
The relative importance of canopy size and induced resistance to Colletotrichum gloeosporioides at atmospheric CO2 concentrations of 350 and 700 ppm on Susceptible Stylosanthes scabra in a controlled environment facility in the field. Up to twice as many lesions per plant were produced in the high CO2 plants, because the enlarged canopy trapped many more pathogen spores. Pangga et al. (2004)
Interactions between Erysiphe cichoracearum and Arabidopsis thaliana under elevated levels of CO2. The number of established colonies on mature leaves increased significantly. Lake and Wade (2009)
Cont
46
The effects of carbon dioxide (CO2) and ozone (O3) on three soybean diseases (downy mildew, Septoria and sudden death syndrome) in the field. Elevated CO2 reduced downy mildew disease severity. But increased brown spot severity and without effect in sudden death syndrome. Eastburn et al. (2010)
The effects of elevated CO2 and temperature on the Incidence of four major chili pepper diseases Anthracnose, Phytophthora blight and two bacterial diseases. Elevated CO2 and temperature significantly increased the incidence of two bacterial diseases. Anthracnose decreased and Phytophthora blight slightly increased. Shin and Yun (2010)
47
Effect of High temp and low moisture on severity
of root rot and wilt of chickpea

Dry root rot
Wilt
Moisture depletion
Soil temperature
Temp Soil Moisture 32 70 To to 35 lt60
Vegetative - Flowering
Seed - Seedling
Flowering - Pod formation
Phy. Maturity - Harvest
Growth stages
Desai, 2010
CRIDA, Hyderabad
48
Effect of low temp and high moisture on chickpea
pathogen

Chickpea
Soil Moisture
Wilt
Collar rot Black root rot
Soil temperature
Seed - Seedling
Vegetative - Flowering
Flowering - Pod formation
Phy. Maturity - Harvest
Desai, 2010
CRIDA, Hyderabad
Growth stages
53
49
Low Temp High Moisture
Phytophthora blight of Pigeonpea Phytophthora
drechsleri

50
Projection of Citrus Canker (Xanthomonas
axonopodis pv. citri) in Australia
Predicted distribution of citrus canker with a 3
C increase in average temperature (2070)
distribution of citrus canker (2006)
51
Puccinia Path in India
Wind
The principle effect of wind on plant epidemics
is in spore liberation and spore dispersal.
Mehta. K.C.(1952)
56
52
Potential migration routes for race Ug99 of the
stem rust pathogen based on prevailing airflows
and regional wheat production areas.
53
Rice Diseases Past Current status
Bacterial leaf blight Minor occurrence in rice growing states Major- aggressive races
Tungro virus Minor importance and localized in northern India Major disease with frequent epidemics
Sheath blight (Rhizoctonia solani) Localized as minor in some rice growing areas Major in most areas
Meloidogyne graminis Localized in hills Now in plains also
54
Wheat Diseases Past Current status
Spot blotch (Bipolaris sorrokiniana) Earlier NEPZ Bihar, West Bengal, U.P., Orissa Major Epidemic from 1990-91 in NWPZ
Heterodera avenae Localized in plains Higher altitudes
55
Effect of Climate Change on Plant Disease
Management
56
Host Resistance
Host Resistance
57

• Cockley et al. (1999) mentioned that durability
  of resistance may be threatened by number of
  infection cycle of pathogen within a growing
  season increased because of one or more following
  factors like
• Increase fecundity
• More pathogen generation per season,
• More sustainable microclimate for disease
  development
• this may leads to more aggressiveness of the
  pathogen races.

• Foliar pathogens have lower infection under
  drought situation, due to lack of required leaf
  wetness for spore germination (Chowdappa, 2010).

• In case of soil borne Sclerotium rolfsii
  infesting groundnut, it has been observed that at
  35 OC resistance variety breakdown and show
  susceptibility (Mayee, 1996).

58
Chemical control
Chemical Control
59
Chemical control may largely affected by climate
change in two way changes in temperature and
precipitation. It may alter the dynamics of
fungicide residue on the foliage of crop.
Morphological and physiological changes in plant
resulting from growth under elevated CO2 could
affect up take, translocation and metabolism of
systemic fungicides.
Change in duration, intensity and frequency of
rainfall events would impact on the effectiveness
of chemical control measures
60
QUARANTINE AND EXCLUSION
Management of climate change will put additional
pressure on agencies responsible for exclusion as
a plant disease control strategy. Use of
Geographical Information Systems and climate
matching tools may assist quarantine agencies in
determining the threat posed by a given pathogen
under current and future climates.
61

• Effects of climate change in India
• Agriculture
• Up to 50 reduction in maize yields
• 4-35 reduction in rice yields (with some
  exceptions)
• Rise in coconut yields (with some exceptions)
  reduced apple production
• Negative impacts on livestock in all regions
• Fresh water supply
• High variability predicted in water yields (from
  50 increase to 40-50 reduction)
• 10-30 increased risk of floods increased risks
  of droughts
• Forests and natural ecosystems
• Increased net primary productivity
• Shifting forest borders, species mix, negative
  impact on livelihoods and biodiversity
• Human health
• Higher morbidity and mortality from heat stress
  and vector/water-borne diseases
• Expanded transmission window for malaria

62

• Overall risks posed to India
• Food security - predominantly monsoon dependent
  and rain-fed agriculture
• Water security - glacier-fed river and stressed
  ground water systems
• Coastal security - 7,000 km long, densely
  populated coastline vulnerable Andaman Nicobar
  and Lakshwadeep islands
• Livelihood security - natural resource-dependent
  rural communities
• Energy security - climate change further
  complicated by our dependence on coal (50 of
  total energy mix)

63

• Regional security challenges
• India is surrounded by institutionally weak and
  highly vulnerable states
• Maldives (pop. 300,000) over 80 of country lt1m
  above MSL
• Bangladesh (pop. 160 m) 1m rise in sea-level can
  inundate 17.5 of its land area and 11 of its
  population
• Greater number of IDPs but considerable risks of
  climate-induced transboundary migration
• Tensions over river-water sharing with Pakistan,
  Bangladesh, Nepal and China
• Tensions over shifting coastal and maritime
  borders resulting from sea-level rise.
• Effects of climate change in AN and Lakshwadeep
  islands can potentially impact Indias power
  projection ability in the wider region

64
Adaptation Measure for Climate Change

• Integrated pest management
• Using available early warning system for
  diseases.
• Biological control measures.
• Utilization of indigenous traditional knowledge
  base for disease control.
• Soil solarization technique
• Breeding for disease, pest and drought resistance
  varieties.
• Careful tracking of geographical distribution of
  plant virus diseases and their vectors.
• Phytosanitary regulations to prevent or limit the
  introduction to risky plant pathogens.

65
Conclusion

• Climate systems may change more rapidly than in
  the past.
• If changes in atmospheric composition and global
  climate continue in the future as predicted,
  there will be relocation of crops and their
  diseases and impacts will be felt in economic
  terms from crop loss.
• Changes in level of CO2 and O3 will influence
  disease by modifying host physiology and
  resistance.
• Changes in temperature and precipitation will
  influence disease epidemiology.
• Survival, longitivity and aggressiveness are
  increased with passage of time due to change in
  climatic condition.
• Best management will be from exclusion or early
  detection and elimination wherever it is possible.

66
Future thrust

• Current strategies for management need to
  modified accordingly.
• Development and validation of weather based
  disease forecasting models for Indian condition
  to serve as early warning systems.
• Breeding for disease tolerant cultivars needs to
  be initiated.
• Studies needs to be initiated on changes in host
  physiology, pathogen life cycle and host pathogen
  interaction caused by changing climatic
  parameters.

67
Thank You
REMEMBER, WE HAVE ONLY ONE EARTH