India with diversified agro - ecosystems responded spontaneously to
the technologies of green revolution with introduction of several components
in crop production like developing and adopting high yielding varieties,
hybrids, usage of new agro-chemicals and adoption of intensive crop
cultivation techniques.
The gains of green revolution reflected in the shape of production
of 200 million tonnes of food grains, 25 million tonnes of oil seeds
and 15 million tonnes of fibres per annum. But these steady gains in
agricultural production over past four decades have not fully overcome
the problem of rising demand caused by soaring population growth.
Adding to the population explosion, there were frequent set backs
to crop production experienced in the shape of abiotic and biotic stresses
during the last two decades in several food crops where intensive farm
practices were adopted.
Among these stresses on major crops, increased pest populations leading
to the stage of collapse of economy, at times keep the planners and
executors to be helpless. In the past one and half decades, the periodical
unabated explosions of aphids, whiteflies, bollworms, pod borers, defoliators,
coccids, cutworms, plant hoppers etc., as direct crop damagers and disease
transmitters in different regions of the country have made agriculture
less remunerative and highly risk prone.
The ability of some of these pests to develop resistance curbs the
effectiveness of many commercial chemicals. Resistance has accelerated
in many insect species and it was reported that more than 500 insect
and mite species are immune to one or more insecticides at present.
Similarly about 150 plant pathogens such as fungus and bacteria are
now shielded against fungicides. Some of the weedicides also found effective
earlier failed to control weeds now-a-days.
Experts assessment reveal that around 22 per cent of yield losses
in major crops like Rice, Cotton, Groundnut, Sugarcane, Sorghum, Tomato,
Chillies, Mango, Grapes, etc., can be attributed to insect pests.
Hence, there is need to reduce if not eliminate these losses by protecting
the crops from different pests through appropriate techniques. At present
day the role of crop protection in agriculture is of great importance
and a challenging process than before, as the so called resistant species
should be brought under check.
All other management practices of crop husbandry will be futile if
the crop is not protected against the ravages of pests. In absence of
crop protection the yields may be drastically declined. The entire effort
of growing a crop will be defeated in absence of crop protection resulting
in financial loss to the grower. So the crop protection against various
pests is a must in agriculture.
'PEST' is an organism that causes damage resulting in economic loss
to a plant or animal. It can also be said that pest is a living organism
that thrives at the expense of other living organism.
The expression of "Pest" is used very broadly to insects, other invertebrates
like nematodes, mites, snails and slugs, etc., and vertebrates like
rats, birds, jackals, etc., that cause damage to crops, stored products
and animals.
Disease producing pathogens of plants and weeds are also referred
as crop pests.
It is a well known fact that insects being widely distributed became
more problematic in tropical climate. Of 1.5 million species of insects
so far described few are so conspicuous in their presence due to their
ability to develop rapidly and becoming serious by attacking food crops
directly and indirectly.
In developing country like ours insects are dominating over other
pests by acquiring characters like resistance to toxic chemicals, and
resurgence, particularly in intensive crop management regions of the
country. The losses caused by insect pests like Spodoptera, Heliothis,
Whitefly and Aphids are so enormous that these made the farmer to disturb
the present ecosystems with continuous use of excessive insecticides.
The losses caused by different pests and monitory losses
incurred as a result of loss is furnished below
Pests
Loss caused (in percentage)
Monitory loss in crores (Rs.)
Insects
20
1200
Storage Pests
7
420
Diseases
26
1560
Weeds
33
1980
Rodents
6
360
Miscellaneous
8
480
Total
100
6000
Source : Pesticide Information April - June, 1995.
IPM is a system that in the context of the associated environment
and the population dynamics of the pest species utilizes all suitable
techniques and methods in as compatible manner as possible and maintains
the pest populations at levels below those causing economic injury (FAO,
1972). In integrated pest management both crop and pest are seen as
part of a dynamic agro-ecosystem.
IPM attempts to capitalize on natural biological factors that limit
pest out breaks, only using chemicals as a last resort. The goal is
to reduce crop damage to a level where it is economically tolerable,
using control measures whose cost both economic and ecological is not
excessive. A number of non-chemical cultural practices form the core
of IPM. But IPM does not preclude chemical pesticide usage. Pesticide
usage is one of weapons in the management armoury to us that can be
exploited sensibly and judiciously.
IPM In Sustainable Agriculture
For sustainable agriculture IPM is location specific and resource
oriented process in terms of ,
Preserving land races of the crops that can with stand biotic and
abiotic stresses.
Restoring ecobalance to the extent possible.
Highlighting the importance of organic nutrition.
Dovetailing traditional methods with modern techniques.
Involving physical labour along with agro-machinery and chemical
means.
Developing human resource to understand the recyclic (energy transfer)
phenomenon of agro-ecosystems.
Leading to less risk-prone vis-a-vis low input oriented agriculture.
Acceptable socially, economically and politically.
While developing IPM strategy one has to select different components
that are readily available, economical and applicable at field level.
To cater the needs for location specific cropping systems the suitable
technologies should be developed by Research workers from time to time.
The research findings that are practically implementable should be
popularized by the Extension workers through education to farming community.
Farmers have to be trained in scouting, diagnosis of pest infestation
and arriving ETLs for need based chemical application in time.
Farmers should also be trained in selection of suitable pesticide,
use of proper lethal dose and proper coverage of foliage to avoid risks
of resistance, resurgence and residues. Farmers training is a continuous
process and is an important integrated part for successful implementation
of IPM.
An healthy, meaningful co-operation is very much needed from corporate
pesticide industry to make IPM successful at farmers level. The pesticide
industry should not wield enormous financial power and maintain market
dominance against ecological and environmental safety.
When to use Crop Protection Chemicals
When adult activity is in increasing trend resulting in unacceptable
pest load on crop as indicated by pheromone, light and sticky traps.
When field scouts fixed plot survey indicate a particular dominating
stage of pest in the field.
When the bio-agents existing in the area did not attain a level,
that can influence the pest population.
When insecticide resistance due to usage of insecticides does not
surface practically.
When residues of insecticides do not become problematic.
When the role of bio-agents and other environmental resistance factors
are less perceptible.
How can a Crop be monitored
A field crop is monitored to determine a pests economic status or
to determine whether a natural enemy is at a level capable of suppressing
a pest's population density. So identification of pests and beneficial
insects is of prime importance before any control operation is executed.
Monitoring tools like pheromone, light and sticky traps can be advantageously
used. Field scouting adopting fixed plot survey or roving survey should
be taken from time to time to monitor the crop in determining whether
the pest population attained ETLs.
Which Products Form Part of The Ipm Strategy
Different monitoring tools like pheromone traps, light traps, coloured
sticky traps.
Preserved specimens of pests, natural enemies, infested plant portions
as identification tools.
Bird perches.
Seed dressing chemicals and seed dressing machines.
Seeds of Resistant varieties.
Ecofriendly insecticides like Neem products and bio-fungicides like
Trichoderma sp.
Natural enemies like Trichogramma egg cards, and microbial preparations
of NPV & Bt.
Soft and target specific pesticides.
Bait preparations.
Good plant protection equipment.
Finally mostly farm based renewable resources that can enhance the
recycling phenomenon of ecosystem should form part of IPM strategy.
