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Posts Tagged / Climate Change

  • Mar 01 / 2012
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in NEWS, Quotes

Climate change threat to food produce in India, says study

Date:Mar 1, 2012

‘Erratic rainfall and rising input costs forcing farmers to migrate’

“Unable to clear a loan of Rs 2 lakh, my son committed suicide. I had to sell my ancestral house and cattle to repay the loan,” says Lakshmi Devi, 48, of Pathakotha Cheruvu village in Andhra Pradesh’s Anantapur district. Devi’s woes did not end with the repayment of loan. Managing her farm is becoming increasingly difficult, partly because it is expensive, and mostly because of the  unpredictable weather. Changes in rainfall pattern have increased pest-related problems, especially during the flowering season, she says. Many, like her, are facing similar problems: erratic rainfall pattern affecting yield, pests and related diseases on the rise; and losses staring them in the face. Many farmers, like Devi’s younger son, choose to migrate.

Lakhsmi Devi, who grows groundnut on her 2.4 hectares, was one of the thousand farmers ActionAid India and Centre for Sustainable Agriculture in Hyderabad spoke to, for their study on climate change and agriculture. The study, carried out in 15 villages in three states, reiterates that a quarter of agricultural produce is under threat from climate change and that the small and marginal farmers would be impacted the most (see box: Study findings).

Most villagers in the districts under study complained of shift in the intensity and distribution of rainfall. “The rains are so scattered that at times it rains in the village, but the fields remain dry. The rainfall pattern was not like this 10-15 years ago,” said Birendra Sahariya, 40-year-old farmer from Sipri village of Lalitpur district.

G V Ramanjaneyulu of the Centre for Sustainable Agriculture says the study did not find much variation in rainfall at the district level, but found the distribution of rainfall had changed vastly. “People resort to migration because there is little else they can do,” Ramanjaneyulu adds.

Early flowering of mango and mahua, an important non-timber forest produce, has also been seen in Odisha, says Ranjan Panda, convenor of Water Initiatives, which focuses on water and climate change links in Odisha. “Western Odisha is increasingly experiencing desert-like climate; the day time temperatures are increasing and the night-temperatures are decreasing,” says Panda. Referring to the study, he adds that more such studies are required to develop an in-depth understanding of how climate change impacts agriculture.

Farmers are also grappling with increasing input costs with respect to agriculture. In Anantapur district alone, cost of production has increased by 500 per cent in the past 10 years, whereas prices increased by 25 per cent. The study also notes that after manufacturers were given a free hand to fix the price, the cost of fertilisers, except urea, increased by more than 300 per cent. Despite this, there is an increased dependence on chemical fertilisers to meet soil fertility needs. “There is an urgent need to revisit agricultural practices,” says Kishor Tiwari of Vidarbha Jan Andolan Samiti in Nagpur.

Study findings

The study, by ActionAid India and Centre for Sustainable Agriculture in Hyderabad, covered five villages each in the districts of Lalitpur in Uttar Pradesh, Anantapur in Andhra Pradesh and Bolangir in Odisha. About a thousand farmers were interviewed from the 15 villages and some common impacts were found in all the three states.

These include changes in the distribution of rainfall, delayed monsoon, increase in pests as well as migration. In Anantapur district, for instance, the first monsoon showers would arrive by early June; now they arrive end of July. This has altered cropping pattern and has given rise to new forms of pests and diseases in the past five to six years. Also, farmers observed that the groundwater table in the district had declined by 30 to 90 metre in the past 10 years.

In Odisha, after the introduction of Bt cotton in 2005 in the water-deficit region, mono-cropping increased which led to losses and farmers resorted to migration. In Lalitpur, traditional crops and seeds had disappeared altogether from the villages. Also, rainfall in 20 of the past 28 years was less than the average rainfall of 1,044mm, with 2005 and 2008 being the exceptions, the study noted.

Farmers said that during the 80s, dew/fog was common in November and December. This was helpful in ripening of the crops such as pulses and mustard. But dew has not been there for the past 15-20 years and crops mature early and grains remain undeveloped.


  • Aug 16 / 2009
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Climate change and Pest Management in Agriculture  

Dr. G. V. Ramanjaneyulu, and Dr. T. A. V. S. Raghunath[1]

Insect populations like all animal populations are governed by their innate capacity to increase as influenced by various abiotic and biotic factors.  The changes caused by the natural evolutionary forces are accelerated with the human interventions.  After the changes like depletion of natural resources, environmental pollution, extinction of certain species of plants and animals, the Climate Change particularly caused by inadvertent anthropogenic disturbances has become more evident. Projected carbon dioxide levels in the twenty first century are two to four times higher than the pre industrial era.  Global climate change resulting in changes in temperature rise and precipitation patterns, could accentuate the vulnerability of agriculture.  IPCC (International Panel on Climate Change) predicted that global mean temperature would rise between 0.9 to 3.50 C by the year 2100 (IPCC, 2001).  Global warming may increase average water vapour and evaporation, increase in precipitation in high-altitude regions, significantly alter the Monsoon pattern resulting in long dry spells and heavy downpours and change in storm patterns which could influence the global movement of pests, especially pathogens.

In agricultural ecosystems, soil, plant and animal interactions are rarely persistent enough, in time and space, to provide the ecological stability but result in dynamic equilibrium.  Pest shifts are observed with changes in the ecological balance.  The natural balance between beneficial and harmful insects changes with the cropping patterns, pest management practices and variability in environment. Weather and Climate have an impact on the pest population.  ‘Weather’ is short term variation of the atmosphere at a given time with respect to temperature, pressure, wind moisture, cloudiness and precipitation.  ‘Climate’ is usually defined as the statistical collective of the weather of a specified area during a specific interval of time or as the prevailing or average weather conditions of an area over a long period.  Climate change leads to shifts in the pest incidence, migration and viability thresholds.  Today, farming and farmers lives are already effected by the pests and pest management practices they adopt. Hence, understanding the intricacies of climate change on pest management in agriculture is crucial.

Weather has both direct and indirect effects on the insect populations. The direct effects of weather on behavior and physiology are well documented.  Reproductive biology of an insect may be affected both positively and negatively which ultimately affect its populations.  Climate change would shift pest populations as it would shift important determinants of pest incidence, namely  temperature, precipitation distribution, and wind pattern.

Temperature: All life survives with a  certain narrow range of temperature.  Deviations from this in optimum range on either side is tolerated to some extent, depending on the physiological adaptations of the concerned species or populations.  Temperatures above or below these limits can prove lethal.  Exposure to lethal high or low temperatures may result in instant killing or failure to grow and reproduce normally.  Harmful effects of exposure to sub-lethal temperatures may be manifested at later critical stage like moulting or pupation.  rise in temperature might also have a negative effect on delicate natural enemies such as hymenopteran parasitoides and small predators.  This may effect natural enemy-pest relationship. For e.g. Brown Plant Hopper is 17 times more tolerant to 400 C than its predator Cyrtorrhynus lividipennis but wolf spider Paradosa pseudoannulata is tolerant to 40 0 C.

Moisture:  Most terrestrial insects live in an environment, which is dry.  The only source of water for insects is the water obtained with food material from their host plants.  These insects have, therefore developed a variety of mechanisms to conserve water.  In spite these mechanism, exceptionally dry air may prove lethal to most insects.  Likewise, excessive moisture may also adversely affect many insects by encouraging disease outbreaks, affecting normal development and by lowering their capacity to withstand lower temperatures.  The reproductive capacity of the insects is also affected by moisture but there are great differences in the capacity of different insects to tolerate conditions ranging from extreme dryness to near saturated environments.  For example, incidence of Rice Hispa in Telangana region has increased in the last two years due to prevailing dry situations.

There is a shift observed from the leaf/fruit eating caterpillars to sucking pests in the recent years.  While monoculture of crops/varieties and chemical pest management practices understood to have resulted resulted in such pest shifts, climate change also have also contributed for such shift.  For example in cotton there is a shift towards sucking pests (mealy bugs, jassids) particularly after the introduction of Bt cotton.  Similarly, Aphid incidence in Groundnut, Thrips and yellow mites in chillies are observed.  Most of the sucking pests are also vectors of viral diseases. With increasing incidence of sucking pests viral diseases are also increasing e.g., Budnecrosis in Groundnut, Tobacco Streak Virus incidence in Cotton, and similar viral problems in most of the fruit crops, vegetables.

Other impacts of Climate change on pest incidence

a. Increases in UV-B radiation is likely due to depletion of ozone layer resulting in increased production of plant metabolites that might change the host-pathogen relationships and the status of the individual pest.

b. Under changed climatic condition, cropping pattern and intensity may be changed and to cope up the situation new varieties,  or new methods of pest control or new chemicals to kill a pest may be released which might have either positive or negative impact on pests.

Ecological Pest management

Pest is not a problem but a symptom. Disturbance in the ecological balance among different components of crop ecosystem (biotic and abiotic) makes certain insects reach pest status.  These problems of increasing pest incidences and pest shifts can be tackled only with better  environmental friendly pest management practices.  Ecological approaches to pest management should be based on knowledge and skill based practices to prevent insects from reaching damaging stages and damaging proportions by making best use of local resources, natural processes and community action’.

  • Understanding crop ecosystem and suitably modifying by adopting suitable cropping systems and crop production practices. The type of pests and their behavior differs with crop ecosystem. Similarly the natural enemies’ composition also varies with the cropping systems.
  • Understanding insect biology and behavior and adopting suitable preventive measures to reduce the pest numbers.
  • Building Farmers knowledge and skills in making best use of local resources and natural processes and community action. Natural ecological balance which ensures that pests do not reach a critical number in the field that endangers the yield. Nature can restore such a balance if it is not meddled with too much.

In Andhra Pradesh such initiative implemented through Federations of Women Self Groups across the state in 18 districts in more than 3000 villages covering more than 14 lakh acres in 2008-09 in the name of ‘Non Pesticidal Management’ has shown that such eco-approaches can bring in both ecological and economic benefits to the farmers.  This program started in 2004-05 with technical support from Centre for Sustainable Agriculture and financial and administrative support from Society for Elimination of Rural Poverty (SERP).  The farmers in the villages are grouped into Field Schools and trained by the local civil society organisations.  The regular and incidental technical support is institutionalized and community managed.  The learning from this program are now considered by the ‘National Mission on Sustainable Agriculture’ as part of National Action Plan on Climate Change to be implemented across the country during the 11th five year plan.

[1]    The aurthors can be contacted at Centre for Sustainable Agriculture, 12-13-445, Street no-1, Tarnaka, Secunderabad-500 017 ramoo@csa-gmail.com, http://www.csa-india.org