1. Plant Protection Measures
against
insect pest and diseases

2. Plant protection
measures
● The comprehensive approach which is used to reduce the pest population under the
threshold level which can be tolerated by crops.
● It doesn’t mean to eradicate the pest totally, instead reduce their population which can be
tolerated by plants without being damaged.
● It combines different means to maintain plant in quality environment.

3. Physical methods
Are the practices that reduce
plant pests by using devices
which affect pests physically or
alter their physical
environments.

4. (A) High temperature: exposing insects to high
temperature (about 60-66 degrees Celsius)
 For eg: killing of stored grain pest by
superheating of empty go-downs and sun
drying of products for 3-4 hrs.
1. Manipulation of
temperature

5. (B) Low temperature: exposing insects to below
freezing point, as insects become inactive and
nearly die below 0 degrees Celsius.
2. Manipulation of
temperature

6. ● Insects are mainly available in moist
and humid conditions. So, they can be
controlled by draining excess water
from crop area.
● For example: the moisture content of
stored grain should be reduced below
10 degrees Celsius to control stored
insects.
● Disease incidence can be reduced by
reducing relative humidity of crop
canopy and nearby surroundings.
3. Manipulation of moisture

7. 4. Manipulation of
light
• Lights of different wavelength can
be used to trap insects and control
them.
• For eg: most of moths, borers and
beetles are attracted by ultraviolet
lamps.

8. 5. Use of radiant
energy
• Different rays such as X-rays, Beta rays,
gamma rays are used to control insects.
• Are highly effective in causing death of
tissues and making insects sterile.
• For e.g.: screw-worm flies were
eradicated from Florida by the help of
Gamma rays.

9. 6. Use of sound waves
• Sound waves are used attract male
mosquito and are made sterile
with the help of electronic flash
gun.

10. Mechanical methods
Are the practices that reduce
plant pests by using
mechanical devices or
equipment.

11. • Removal and complete destruction of insects by
manual operation.
• For example, larva and eggs of large sized insects
such as hairy caterpillar, leaf roller, tobacco caterpillar,
mustard sawflies, white grubs, red pumpkin beetle,
etc. can be collected and destroyed by handpicking.
1. Destruction

12. ● Trapping devices such as yellow pan
traps and sticky traps can be used to
control aphids, white flies and fruit flies.
● Sound traps can be used to scare the
insects and make them away from the
fields.
2. Use of trapping devices

13. 3. Clipping and
pruning
• Clipping and prunning the infected
parts helps to remove insects and
diseases from crops.
• For eg: clipping the tip of rice
seedling helps in removing the eggs
of gall midge as they lay eggs near
the tip of leaf.

14. 4. Exclusion
• Avoiding the contact of pests with crop
plants. They are practiced by following
ways:
a) Bagging/ Wrapping of fruits
b) Banding
c) Trench digging
d) Water barrier

15. A. Bagging/ Wrapping
• Helps to exclude fruit flies and other
insects to lay eggs on the surface of
fruits.
• For example, bunches of grapes are
protected from wasps and bees,
pomegranate fruits are protected from
laying of eggs by butterfly with the help
of bagging.

16. B. Banding
• Applying greasy or sticky materials
around the trunk of plant to avoid
upward movement of insects from
ground.
• For example, nymphs and adults of
mango mealy bugs are prevented from
destroying mango tree by the help of
banding tree trunk with sticky substance
of about 15 cm wide.

17. C. Trench digging
• Digging of trench around the main field
helps to control the infestation of field
migrating insects such as grasshopper,
soybean hairy caterpillar, cricket, etc.

18. D. Water barrier
• Water barrier are used to control ants
attack on bee-hive colonies by putting
water in bowl which is kept below 4 legs
of bee-hive stands.

19.  Low cost
equipment and
home labors are
used.
 Provides
immediate results.
 No any side effect
and residue
problem.
Advantages of
mechanical
methods
 Requires more time
and is highly laborious.
 Not applicable in
commercial
agriculture.
 Small pests cannot be
controlled by this
method.
Disadvantagof
mechanical
methods

20. Cultural methods
Are the practices that are
adopted by the people from
the experience of their
ancestors.

21.  Too early or too late sowing of crops
causes incidence of pests.
 For eg: early or late sowing of mustard
crops results higher incidence of
aphids.
1. Time of sowing and
harvesting

22. ● Helps to break the lifecycle of
insects, pests and nematodes.
● Enhances the fertility condition of
soil.
● Repeated growing of single crop
harbors pest infestation.
2. Crop rotation

23. 3. Use of manure and
fertilizer
 Land supplied with balanced
amount of fertilizer is less affected
by pest as compared to either
excessive or less fertilizer.
 For eg: incidence of borers, plant
hoppers and gall midge in rice
increase with excessive use of
fertilizer.

24. 4. Tillage
Helps in controlling many insects,
diseases, nematodes and weeds.
Reduces pests either by damaging
mechanically or by burying or
exposing them.

25. ● Includes collection and destruction
of stubbles, stalks and other
residues after the harvest of crop.
● Helps in elimination of hibernation
of insects and over wintering or over
summering diseases.
● For eg: collection and destruction of
infested fruits help in elimination of
fruit flies.
5. Sanitation and good
husbandry

26.  This methods is
readily available
and easily adopted
by farmers.
 Doesn’t requires
more investment.
 Safe to human,
animal and natural
enemies because it
has no any residual
effects.
Advantages of
cultural methods
 This methods differs
with different pests.
 Doesn’t give complete
control of insects.
 Requires perfect
knowledge about life
cycle, nature of
damage and habit of
pests.
Disadvantagof
cultural methods

27. Biological methods
Are the practices were we use
different biological organisms
for the control of plant pests.
They may be micro-organisms
or macro-organisms.

28. ● All the organisms which prey or
feed upon other organism for
survival.
● Generally larger than their prey.
● Requires more than one prey in
their life time.
● Are highly active and aggressive to
their prey.
● For eg: mantis prey upon moths
and other insects, lady bird beetles
are the predator of aphids.
1. Predators

29. ● They parasitize and finally kill their
host.
● Differ with predator by the mode of
living in immature and adult stage
(parasitic in immature stage and
free living in adult stage).
● Requires one host to complete their
life cycle.
● For eg: Tichogramma spp. Is the
egg parasitoids of Maize stem borer.
2. Parasitoids

30. ● Are the organisms which live and
totally depend on other organism
for food, shelter and to complete
their life cycle.
● Are generally smaller than their
host and they don’t kill their host
immediately but weaken them
continuously.
● For eg: lice, tapeworms, etc.
3. Parasites

31.  Has no any side
effect.
 Doesn’t occur pest
resistance problem
as chemical
method.
 Is eco-friendly and
doesn’t cause harm
to natural enemies.
Advantages of
biological methods
 Requires good
knowledge about the
pests.
 Highly trained and
experienced experts
are needed
 Requires perfect
knowledge about life
cycle, nature of
Disadvantage of
biological methods

32. Chemical methods
Are the practices were we use
pesticides to kill, deter, change
behaviour and impair sterility in
pests.They are widely used in
the world. They are effective
and give quick result.

33. Botanical pesticides-
● Plant origin.
● More than 2000 species are
reported to have pesticidal
properties.
● For eg: neem, tobacco, bojho, etc.
The pesticides can be
divided into:

34. Inorganic pesticides-
● Are the pesticides which mainly
contain minerals such as arsenic,
mercury, etc.
● For eg: lead arsenate, sodium
arsenate, Paris green, etc.
The pesticides can be
divided into:

35. Organic pesticides-
● Are the pesticides which mainly
contain carbon, hydrogen and one
or more other element which has
pesticidal property such as chlorine,
phosphorous, sodium, etc.
● For eg: DDT, BHC, Malathion,
Parathion, etc.
The pesticides can be
divided into:

36.  Highly effective and
gives quick result.
 Broadly effective to
different types of
insects.
 Materials are easily
available in the
market.
Advantages of
chemical methods
 Problem of development
of pest resistance against
chemical pesticides.
 High residual effect and
can be injurious health
wise to host plants,
animals and even human.
 Not effective in long run
and environmental basis.
Disadvantage of
chemical methods

37. Regulatory methods
Method where legal enforcement for
the control of pest is followed.
Regulates the entry and outgoing of
pest from one region to another and
also from one country to another.
Plant protection act was established in
1973 for the legislative control of plant
pest.
Plant protection act prohibits or restrict
the entry of plant and plant products in
Nepal i.e. affected by pests.

38. Regulatory methods
Plant quarantine program has been
established to stop the import of plant
pests in Nepal.
Centers where plant quarantine
activities are followed:
 Tribhuvan International Airport
 Biratnagar Check Post
 Kakadbhitta Check Post
 Birgunj Check Post
 Bhairahawa Check Post
 Nepalgunj Check Post
 Pashupatinagar Check Post, etc.

39. Genetic methods
In this method, genetic knowledge is
used to control the plant pests. They are
also called innovative methods. They
include genetic alteration of the
behavior of pests.
Some of the genetic control methods
are described below:
I. Insect attractants
II. Insect repellants
III. Antifeedants
IV. Sterile male technique

40. I. Insect attractants
 Are made of some chemicals which
have power of attracting pests
towards foods, host plants or
opposite sexes.
 For eg: food lures such as cure lure,
methyl eugenol , etc.
phermomones such as terpenes in
aphids, alkyl acetate in honey bee,
etc.

41. II. Insect repellants
 Are the substances which repel pest
by making food or living condition
unsuitable for them.
 For eg: pyrethrum, citronella oil,
Bordeaux mixture, etc.

42. III. Antifeedants
 Are the chemicals which inhibit
pests to feed plant or plant parts
when they are present or applied on
plants.
 Some of the common antifeedants
are neem extracts, tannins, lignins,
etc.

43. IV. Sterile male technique
 Also known as autocidal technique.
 In this method, male insects are
made sterile and are released in the
environment. When they mate with
female insects, the progenies don’t
produce. Hence, population is
controlled.

44.  Required in small
amount and very
effective in long
term basis.
 Ecologically sound
and non toxic.
 Do not have
residual effect.
Advantages of
genetic methods
 The genetic method is not
applicable to every pest.
 Requires good knowledge
and skill.
 May be costlier than other
method.
Disadvantage of
genetic methods

45. Integrated pest management
(IPM)
The use of chemical pesticides becomes very
popular after the 2nd World War where DDT was widely
used. Later on, BHC and Organophosphate were also
discovered and were widely used. Due to the excessive
use of these chemical , negative effects became
prominent. The problem of excessive use of these
pesticides was highlighted by Rachel Carson in
published book “Silent Spring”. Due to high persistence
and residual effects of those insecticides, many of them
had been banned or restricted to use in agriculture. To
overcome the problem of chemical pesticides, a new
sound and sustainable concept of Integrated Pest
Management (IPM) was introduced and promoted
worldwide since 1983.

46. Integrated pest management
(IPM)
IPM is defined as a sound management practice where
different methods of pest control are applied in an integrated
manner in order to maintain the pest below economic threshold
level with a minimum use of chemical pesticides. Chemical
pesticides are only used when there is no any option left
to control pest. It is the economically justified and
sustainable method of crop protection where all suitable
techniques are applied in an integrated way which aims
in maximizing profit with least damage to the
environment.

47. Principle of IPM
 Grow healthy crop
 Regular monitoring of the field
 Conservation of natural enemies
 Make farmers expert

48. Tools of IPM
 crop varieties having resistance/ tolerance
to the pest.
 use of sex pheromones (cure-lure, hue-
lure, methyl eugenol, spodo-lure, etc.)
 use of light trap and funnel trap.
 use of chemosterilants. some chemicals
when used against the insect make them
sterile. Eg: Alphutate, tepa, metepa,etc.
 Botanicals such as Neem cake, titepati,
asuro, banmara, etc.
 mineral oil, kerosene oil, petroleum
product and rapeseed also may serve the
IPM tool.

49. Tools of IPM
 use of bio pesticides
 use of eco-friendly pesticide and microbes
such as bacteria, virus and fungi (NPV, Bt,
EM)
 Insect growth regulators, chemosterilants,
antifeedants, etc can be used.
 Biological control agent such as predators
and parasitoids rearing and use.
 Trap crop such as marigold and maize
along the border of tomato to manage
tomato fruit worm.
 Intercropping
 Sticky trap, yellow trap, etc.
NPV- Nuclear Polyhedrosis Virus
Bt- Bacillus thuriengenesis
EM- Effective Microorganism

50.  Sustainable method of
pest control as it has
low risk of the
environment pollution
and health hazards.
 Cheaper and eco-
friendly in long term.
 There is good
promotion, effective
use and conservation
of natural enemies in
this method.
Advantages of IPM
 Requires a good
knowledge on biology and
life cycle of pests.
 Only effective in long
term, but is not effective
in short term.
 Costlier to adopt.
Disadvantage of
IPM

51. Thank You..