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Major advisor Dr. S.K. Dwivedi

Presented byBhaskar soni

M.Sc. (Ag.) Final yearRoll No - 5985

Direct and indirect effect of climate change on plant processes

Department of Plant physiologyJawaharlal Nehru Krishi VishwaVidyalaya, Jabalpur (M.P.)

INTRODUCTION climate is the most dominating factor influencing the suitability of a crop to a particular region.

The yield potential of a crop mainly depends on climate.

More than 50% of variation in yield of a crop is due to climate differences.

Climate change directly affects rate of physiological process and biochemical processes.

Excess carbon dioxide in the atmosphere has the potential to increase crop growth.

Elevated levels of carbon dioxide reduce the protein content of wheat grain.

Climate :- Climate is weather conditions related to longer

areas like zone, state country. Longer duration of time like month, season or year.

Climate change:- Climate change is a significant and lasting

change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions, or in the distribution of weather around the average conditions.

Measures of Climate Change

1. Glaciers

2. Precipitation Trends

3. Sea-level Rise

4.Atmospheric Co2 concentration

5.Green house effect

1. Glaciers:- Model Studies indicate that CO2

induced global warming will result in significant melting of earth’s glaciers.

2. Precipitation Trends:- Global warming is predicted to enhance atmospheric moisture storage resulting in increased net precipitation.

3. Sea-level Rise:- The possibility of large

sea-level rises as a result of global warming. Sea levels rise 17 centimeters in the 20th century.

4. Atmospheric co2 concentration:- Co2 concentration Increased over

19% from 315.7ppm to 376.1ppm (on average, over 1.3ppm per year) during 1958 to 2003. (Measurement at Mauna Loa observatory Hawaii)

The Greenhouse Effect

Sun's energy warms up the Earth, our planet radiates some of this heat back out towards space. Certain gases in the atmosphere act like the glass in a greenhouse, allowing the sun's energy in but preventing heat from escaping. Greenhouse Gases:- CO2, CH4 CFC, N 2 O, SO 2

Global warming

Increasing in temperature near earths. Increasing in temperature due to Increasing atmospheric CO2

concentration and green house gases.

DIRECT EFFECT OF CLIMATE CHANGE ON PLANT PROCESSES

Effect of Temperature:-

Increase transpiration rate

Reduce grain size.

Low light intensity and low temperature reduce photosynthesis, impede translocation of photosynthates from the flag leaf to panicle, decrease no. of filled grains and grain yield.

Faster plant development.

Grain filling is faster with increase in temperature in maize and decrease grain weight .

Effect of atmospheric CO2 concentration:-

Reduced transpiration.

Gas exchange is reduced for both C3 and C4 plants.

Change in a quality of biomass – more sugar

Increases in atmospheric CO2 concentration affect plants photosynthesis, resulting in increases in plant water use efficiency, enhanced photosynthetic capacity and increased growth.

Increased CO2 can also lead to increased Carbon : Nitrogen ratios in the leaves of plants.

Growth of plants at elevated CO2 concentrations of 475–600 ppm increases leaf photosynthetic rates by an average of 40% (Ainsworth & Rogers 2007)

Environmental factor that interacts with elevated CO2 is atmospheric ozone (O3), a gaseous toxin

Oct. 26 to Nov 1, 2014 397.22ppm (last weak)Oct. 26 to Nov 1, 2013 394.17ppm (1 year ago)

Recent Data

Effect of Rainfall:-

Cell growth, cell development and protein synthesis are adversely affected by the rainfall.

Stomatal closure due to water stress restrict carbon dioxide intake leading to reduced photosynthesis.

Water stess is affects fixation, uptake and assimilation of nitrogen.

The promoting growth hormones like cytokinin, gibberellic acid and indol acetic acid decreases.

Increase in abscisic acid content under stressed conditions cause stomatal closure leading to restricted water loss from leaves.

Effect of Wind:- With increase in wind velocity, there is greater increase in cuticular transpiration than stomatal transpiration.

Wind increases evapo-transpiration.

Lodging is another major injury or damage caused by high winds.

Tearing of leaves

Breaking of branches Uprooting of plants.

Lodging in rice

INDIRECT EFFECT OF CLIMATE CHANGE ON PLANT PROCESSES

Pests and diseases:-

Climate change may also impact indirectly on crops through

effects on pests and disease.

wheat and oats become more susceptible to rust diseases

with increased temperature.

suitable for pathogen growth and reproduction if climates.

Warmer winter temperatures could be important in increasing

insect populations (Harrington et al. 2001).

By Weeds:-

Climate change may also impact indirectly on crops through effects on weeds.

Increase water losses thought transpiration rate.

Weeds compete with crop for nutrients, water and other natural resources.

Effect of mean sea-level rise:-

Reduced production and productivity

The rise in sea level will also increase flood risk, raise the groundwater table and prolong water logging.

Saline toxicity.

Strategies for adaptation to climate change

1. Altered agronomy of crops .

2. Development of resource conserving technology.

3. Diversified farming.

4. Crop management strategies.

5. Policy tools for resource management on sustainable basis.

6. Improved risk management through early warning and crop insurance.

It is concluded that climate influence the distribution of crops over different regions of the world.

Climate change directly affects rate of physiological process and other biochemical processes.

The most important research interaction for crop yield & quality improvement would be develop kharif and rabi varieties that can perform well under aberrant weather condition.

Agronomic practices especially for pest and weed management would need more attention whereat programmes to control wind erosion might need strengthening.

Conclusion

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