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| Insects of Food Crops |
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| The growth and yield of food crops are also seriously damaged by various insects. Each insect attacks the crop in its own style and damage the crop to complete its own life cycle. The insects attack almost all parts of crop and the damage may be direct loss of economic product or may be indirect through the reduced growth. |
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| Extent of damage by insects vary greatly depending on the nature of crop, nature of pests, stage of attack, favourable and unfavourable climatic factors etc. The insects can be controlled effectively by use of insecticides. |
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| Pesticides - Why Dangerous? |
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| Commercial manufacture and use of synthetic insecticides in the last six decades has led to many problems such as |
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 Air pollution during manufacturing stages. Bhopal gas disaster is a worst example for air pollution. |
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 Accidental ingestion of insecticides during handling and application leading to innumerable human health hazards like dermatitis and nausea. |
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 Scope for suicidal consumption of pesticides even though many stringent laws are enacted and implemented to sell the poisonous pesticides. |
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 Less than 5% of applied pesticide is really useful to kill the insect or pathogen. Remaining finds its way to pollute the ground water - which may drift into drinking water sources. |
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 Undesirable killing of beneficial organisms like N-fixing bacteria, actinomycetes, blue green algae, earthworms, predators, other annelids, invertebrates etc in soil. This sets imbalance in the eco system and increase the risk of resistance to use of pesticides. |
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 Persistence in human and animal bodies. Some persistent pesticides such as DDT, aldrin, BHC, dieldrin, heptachlor and other organo chlorine chemicals have dangerously persisted and accumulated in human and animal bodies - causing innumerable health hazards. They are not subjected to excretion in animals bodies. |
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| Due to all these dangerous ill - effects, the use of synthetic pesticides needs to be permanently banned for the future of man kind. But, what are the alternatives? The agriculture, in general, and food production, in particular, are badly affected if the pesticides are not used, as the damage by pests continue unabated. |
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| That is why new class of safe synthetic pesticides were found. One group of such pesticides is pyrethroids. Many such pyrethroids like Sumicidin or Decis are widely used by farmers. However continuous use of such chemicals is again not advisable, because |
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 it has potentiality to kill all the insects and this leads to loss of many beneficial organisms and predators. |
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 it has tendency to regenerate the insect attack with higher virulence after controlling the pest for 8 - 10 days. |
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 it has led to development of resistance in insect bodies - by virtue of which application of pesticides later becomes ineffective or higher dose of pesticides need to be applied which can further intensity the resistance. |
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