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A pest is a living organism that survives at the expense
of other living organism resulting in physical damage and economic loss.
Different types of pests that cause damage to the rice
crop
- Insects (sucking and biting insects)
- Plant diseases (fungi, bacteria, virus, and microplasma),
- Nematodes,
- Rodents,
- Snails and slugs.
Losses caused due to pests in Rice
- Rice is essentially a crop of warm, humid environments conducive
to the survival and Proliferation of insects.
- More than 70 species were recorded as pests of rice and about 20
have major significance. Together, they infest all parts of the plant
at all growth stages .
- The insects act as vectors of virus diseases, and are a major factor
responsible for low rice yields particularly in Tropical Asia, the worlds
rice bowl.
- The insect problem is accentuated in multi cropping Or dormancy but
occurs throughout the year in over lapping generations.
- The yield losses vary from 20 to 50 per cent due to the damage caused
by various insect Pests.
Control measures
- Control measures are mainly Cultural, Mechanical, Biological & Chemical
- Among the different methods the farmer is inclined more for chemical
method of control as this method gives quick results .
- No single method is adequate to suppress pest population. Integrated
pest management depending on the need, availability and feasibility
of implementation should be adopted.
Advantages of Chemical Control
- Insecticides or fungicides can be maintained and stored in advance
so that they may be applied very soon after an out break occur or is
expected to occur.
- It usually involves less labour than mechanical methods.
- Infestation over large areas can be treated and in less time than
by other methods.
- It is comparatively cheap and within the reach of many farmers.
- It is very effective in most cases.
Disadvantages of Chemical control
- The insecticides are more indiscriminate in killing insects. Thus,
not only harmful insects are killed, but some of the beneficial insects
as well. This leads to ecological imbalance leading to secondary infestation
of certain pests.
- Most of the insecticides are poisonous to mammals and birds.
- Contribute to environmental pollution,
- Several insecticides are toxic not only to insects but to plants
as well leading to phytotoxicity.
- Indiscriminate use of pesticides leads to the development of resistance
in pests.
- The residues in edible parts of the plant are harmful to consumers.
Conclusion
- Because of these draw backs one should not rely on unilateral
chemical control, but has to adopt integrated pest management by utilizing
all possible methods of control.
- The total Eradication of pests is almost impossible with
available agricultural technology.
- The most Practical alternative is the integrated approach
which Compromises, survey and surveillance to monitor the pests, exploitation
of host resistance, Cultural practices such as judicious use of fertilizers,
crop rotation, sanitation, and correct time of planting, biological
control, using parasites and predators etc., and use of pesticides on
Need basis.
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