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 cause 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 Place 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.
Factors to be Considered While Developing Ipm
Strategy
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.
