Equipments which are used in pesticide application.

1. Plant protection equipments
Equipment for crop protection refers to machinery and implements
protecting crops in a scientific and effective way, aiming at eliminating
pests, diseases and weeds, and ensuring stable and high yield of crops .
In a narrow sense, equipment items used for spraying of chemicals to
protect crops against pests, diseases and weeds
Types of Plant Protection Equipment
1.Sprayers
2.Dusters
1. SPRAYERS
Sprayer is a machine to apply fluids in the form of droplets. It is used for the
following purpose.
∗ Application of herbicides to remove weeds.
∗ Application of fungicides to minimize fungus diseases.
∗ Application of insecticides to control insect pests.
∗ Application of micro nutrients on the plants.

2. The main function of sprayers are
∗ To break the liquid droplets of effective size.
∗ To distribute them uniformly over the plants.
∗ To regulate the amount of liquid to avoid excessive application.
Basic components of sprayer
The important components of a sprayer are:
1. Pump
2. Power source
3. Tank
4. Agitator
5. Distribution system
6. Pressure gauge
7. Pressure regulator
1. Pump
Any spray liquid must be atomized before it leaves the spray nozzle. The pump
facilitate the necessary pressure for this purpose.
Types of Pumps
a. Air Compression or Pneumatic pumps:
These pumps force air into an airtight tank containing spray liquids thus moving
the spray liquid under pressure through the nozzle for its atomization.

3. b. Hydraulic or Positive Displacement Pump:
These pumps take in a definite volume of spray liquid and force it through the
delivery system under pressure. The pumps differ in pressure they produce.
.
2. Source of Power
It is a prerequisite to operationalize the spray pumps.
The source of power may be either:
a. Manual
b. Traction
c. Motor
d. Tractor and air craft engines
3. Spray Tank
A sprayer may have either a built in tank or a separate tank to carry spray liquid.
The tank need be large enough to avoid frequent refilling but not cumbersome to
carry. The tank is equipped with a large opening with a builtin strainer and cap to
fill in the liquid. Small openings pose difficulty in filling and cleaning the tank.
4. Agitator
In order to maintain the homogeneity of the liquid spray, it may be either of
mechanical or hydraulic purpose. Mechanical agitators may be of metal fan or rod
etc. Hydraulic agitator consists of a pipe with several side holes and closed at its
free end. It is placed in the tank and fed with spray liquid with the help of pump.
Liquid jets emerge from these holes, further initiating the agitation to the
complete of the liquid. This is known as ‘By pass system’. Hydraulic agitation is
not thorough but is more convenient in power sprayers used in large tank size.
Using sprayer without agitator should be avoided to apply CPP emulsion and
suspension.
5. Distribution System:
It includes
 Nozzle
 Spray lance
 Spray boom

4. Nozzle The function of spray nozzle is conversion of pressurized spray liquid into
droplets for application on the target.
Nozzles are identified by
a. Droplet size
b. Delivery and
c. Type of Nozzle
Nozzles are generally best suited for certain purposes and less desirable for
others. In general,
 Herbicides are most effective when applied as droplets of approximately
250 microns.
 Fungicides are most effective at 100 to 150 microns.
 Insecticides at about 100 microns.
Hollow cone nozzles-Disc and core type
 These are used primarily where plant foliage penetration is essential for effec
insect and disease control, and where drift is not a major consideration.
 At pressures of 40 – 8- psi hollow cone nozzles give excellent spray coverage
the undersides of reduces penetration correspondingly.
 Droplet size is 100-500 micron
Flat fan nozzles
 These are used largely for broadcast spraying, where foliar penetration and
coverage are not essential.
 The best operating pressure for flat fan nozzles is 15 – 30 psi, which produce
coarser droplets that are not susceptible to drift.
 Droplet size is 100-250 micron
Flood jet nozzles
 These are ideal for high application rates and speeds, because they produce
wide-angle, flat fan pattern.
 Operating flood-jet nozzles at 5-25 psi minimizes drift, but pressure changes
critically affect the width of the spray pattern.
 Generally, the spray generated by the floodjet is not as uniform as the flat-fan
type.

5.  Droplet size is 100-150 micron
Adjustable nozzles
 This model is capable of producing a cone spray in various angles, and also a solid
or broken jet spray.
Single swivel nozzles
 Here the joint of the nozzle and extension rod is capable of swiveling without
leakage, it can be locked for use at any angle between 0 – 180 degrees.
 Droplet size should be adjustable by changing angle 100 -500 micron
Double swivel nozzles
 This has two swivel nozzles instead of one, capable of independent movemen
Double fixed nozzles
 Double fixed nozzles are fixed on the ‘U’ bend, which is, in turn, coupled with
end of a straight extension rod.
 NOTE: Single swivel, double swivel and double fixed nozzles come in both
cones-spray and flat fan varieties.
Spray boom
 This design consists of several nozzles mounted on a rod, ideally suited to ro
crops, and can be operated with foot / rocker / knapsack / power operated
sprayers.
Spray guns
 Spray guns consist of cut-of-value extension rod and nozzle and can be trigge
hand-operated.
 The spray pattern is adjustable from solid jet to hollow cone, and are most wid
used for tall trees.


6. Types of nozzles – (a, b) : Hollow cone
Fig-Parts of nozzle nozzle, (c) : Flat fan nozzle, (d) : Flood jet nozzle
Fig.. Spray from a Variable Cone nozzle
Fig. . Spray from a flat fan nozzle
Drop Size
 Once the spray material leaves the nozzle orifice, only droplet size, number
and the velocity of drops can be measured. Droplet size is measured in
microns. A micron is one millionth of a meter, or 1 inch contains 25,400
microns. To give this some perspective, consider that a human hair is
approximately 56 microns in diameter. All hydraulic nozzles produce a
range of droplet sizes – some large droplets to many small equal number of
smaller and larger drops. The design of the nozzle affects the droplet size
and is a useful feature for certain applications. Large droplets are less prone
to drift, but small droplets may be more desirable for better coverage.
Pressure affects droplet size – higher pressures produce smaller droplets.
 The size of the spray droplet can have a direct influence on the efficacy of
the chemical applied, so selecting the proper nozzle type to control spray
droplet size is an important management decision.
 When the average droplet diameter is reduced to half its original size, eight
times as many droplets can be produced from the same flow.
 A nozzle that produces small droplets can theoretically cover a greater area

7. with a given flow.
 This works down to a particular drop size.
 Extremely small drops may not deposit on the target, as evaporation is
reducing their size during travel to the target and air currents in the drop
pathway may interrupt the drop movement and carry the drop off-target.
 Environmental conditions of relative humidity and air currents (wind) can
have a major affect on drop deposit on the target when small drops are
used to apply pesticides.
 Water-sensitive paper can be used to assess droplet size and density.
Experience has shown that for low volume sprays with medium size
droplets,
 Insecticides should have a density of not less than 20 to 30 droplets/cm2 ,
 Herbicides 20 to 40 droplets/cm2 .
 Fungicides 50 to 70 droplets/cm2 .
Sprayer Calibration
Sprayer calibration aims at obtaining a spray pattern and droplet size that
will ensure optimum coverage of the target area with uniform sized droplets
without causing runoff. Calibration should therefore be taken into account
i. Target Area – area to be sprayed (large area would require higher
quantities)
ii. Droplet size – fine droplets cover a large area with less volume and
reduce run off, but can cause more drift and evaporation losses
iii. Nozzle size and spacing – once the volume of the spray and droplet
size is determined, the nozzle size and spacing on the boom should be
decided keeping in view the height between
the boom and the crop.
iv. Nozzle capacity - Nozzle capacity is a manufacturer’s rating that
depicts what output a nozzle will have at a given pressure. At constant

8. pressure and speed, nozzle capacity is directly proportional to sprayer
output. Output becomes greater as nozzle capacity increases. When
multiple nozzle booms are used on knapsack sprayers it may be necessary
to keep
the nozzle capacity ratings low to avoid exceeding the output capacity of
the knapsack pump. Typical nozzle sizes are 700, 800 or 900 ml/minute.
Smaller nozzle sizes are manufactured by some companies but may not be
universally available. A 1000 ml/ minute nozzle will have twice the output as
a 500 ml/minute nozzle at the same pressure. The angle rating of a spray
tip is not related to output.
v. Speed – keeping boom output constant Speed is inversely proportional
to spray
application. As you walk faster, less spray is applied to a given area.
vi. Pressure - As pressure increases, sprayer output increases. However,
this relationship is not direct. Pressure must increase four times in order to
double nozzle output. Variable pressure will cause variable output.
Pressure may also affect the spray angle of different nozzles. The nozzle
angle rating is for a specific pressure. The spray angle of a nozzle will
decrease when pressure drops below the recommended minimum
pressure for that nozzle. Low pressure nozzles (nozzles that have spray
angles maintained at low pressures) are manufactured, however, they may
not be universally available.
ii. Lance
It is a brass or steel rod, 90 cm in length, attached to a delivery hose pipe of
sprayer and fitted to its free with a replaceable nozzle.
A CPP spray lance is bent at its nozzle forming a goose neck. At the hose end it is
provided with a trigger mechanism to control flow of liquid for a specific purpose.
We may fix the spray lance with plastic shield to prevent chemical from drifting.

9. Plant Protection Equipment
Depending upon the quantity of spray fluid required per unit area, the sprays are
described as
I) High volume sprays- The spray fluid of 450 to 1000 liters required to
cover1/ha crop and droplet size 250 to 500 microns.
II) Low volume sprayers –the spray fluid of 12 to 125 liters required to
cover1/ha crop and droplet size 150-250 microns.
III) Ultra – low volume sprays. The spray fluid 0.5 to 6 liters of liters will be
required to cover one hectare of field crop . However the droplet size is
70 to 150 microns .
Types of Sprayers:
I) High Volume Sprayers:
A) Manually Operated Hydraulic Sprayers:
1. Hand Syringe:
It consists of a cylinder and a plunger, spray fluid has to be contained in a separate
tank. The liquid is drawn on return stroke of the plunger and ejected during the
compression stroke. After each ejected the spray fluid has to be drawn in. It is
useful for small scale spraying in kitchen gardens and pot plants.
2. Bucker Sprayer or Stirrup Pump:
It may consist either of a double acting pump with two cylinders or a single acting
pump with one cylinder. The other parts of the sprayer are the plunger assembly,
foot value assembly, hose, lance and nozzle, a stirrup and an adjustable foot rest.
The pump has to be put in a bucket of any container having the spray fluid. In the
single acting pump the spray discharge is discontinuous since the fluid is ejected
only during the downward compression stroke, while in the double acting pump the
discharge is continuous as the fluid is discharged during both sucdon and pressures
strokes. The tank has a capacity of 10 to 25 liters and is made of galvanized iron,
brass stainless steel or plastic. This type of sprayer is useful for spraying small
trees. Area covered per day is 0.5 to 0.8 ha.
3. Knapsack Sprayer:
This type of sprayer has a flat or bean shaped tank. The tank has a capacity of 10
to 30 liters and is made of galvanized iron, brass stainless steel or plastic. It is
similar to bucket type in principle. It is operated by a lever handle provided inside

10. the tank and it moves up and down inside the container due to the movements of
the pump lever. It is user for spraying field crops vegetables and nurseries. The
area covered per day is 0.8 to 1 ha.
4. Rocker Sprayer or Gatoor Pump:
It consists of a pump assembly, a rocking lever, pressure chamber, and suction hose
with a strainer, delivery hose, cut-off valve and spray lance with nozzle. By rocking
movement of the lever pressure can be built in the pressure chamber and this helps
to force the liquid through the nozzle. There is no built in tank. It can be used for
spraying trees and tall field crops. It covers about 1.5 to 2 hectares of area in a
day.
5. Foot Sprayer or Pedal Pump:
A pedal pump consists of a vertical pressure chamber mounted on to a stand and a
plunger assembly with the plunger rod attacked to a pedal in addition to a suction
hose with a strainer, a delivery hose with an extension rod and spray nozzle. It has
no built in tank. It works on the same principle as the rocker sprayer except that
the pedal is worked up and down by foot in this case where the rocker in a rocker
sprayer is operated forward and backward by hand. In both cases continuous
operation of pedal or rocker is required to maintain high pressure for uniform
spraying. The tank has a capacity of 10 to 30 liters and is made of galvanized iron,
brass stainless steel or plastic. It is used for spraying agricultural crops as well as
small fruit trees. About 1 to 1.5 ha area can be sprayed in a day.
B) Manually Operated Pneumatic Sprayers:
In the sprayer working with air compression system, the pressure is developed on
the air contained in the spray tank, hence some air should be allowed to remained
in the tank which therefore, should not be filled with spray fluid completely. They do
not have agitators and hence are not useful spraying materials which settle down
quickly.
1. Hand Sprayer or Atomizer:
The container for the spray fluid also acts as the pressure chamber. An air pump
attacked to the chamber projects inside. The inner end of the discharge pipe runs
down to the bottom of the container and its outlet terminates in a nozzle. The tank
is filled about 3/4th of it and the pump is worked force air into the space to build
sufficient pressure upon the spray fluid. These sprayers are used extensively in
kitchen gardens, in glasshouses and in doors against house-hold insects. The tank
has a capacity of 10-15 liters and is made of galvanized iron, brass stainless steel
or plastic. The capacity of tank is up to one liter, if used in field it can cover an area
of 0.1 ha in a day.
2. Knapsack Sprayer:
They are adopted for spraying large quantities of liquids. It comprises a tank for
holding the spray as well as compressed air, a vertical air pump with a handle,

11. filling hole with a strainer, spray lance with nozzle and release and shut-off devices.
The tank is provided a convenient rest with the back of the operator and has
shoulder straps that allow it to be carried by him. These sprayers are used against
agricultural pests and mosquito control operations. The capacity of tank is 12 to 16
liters. This pump covers an area of about 0.8 to 1.2 ha in a day.
C) Power Operated Hydraulic Sprayer:
A power operated hydraulic sprayer generally consists of a petrol engine and a
framework. The following are some of the power operated hydraulic sprayer. in
the hydraulic sprayer, a pump supplies energy that carries spray material to the
target (plant foliage). Water is the carrier and the pump creates the pressure at
40-1000 psi. Spray material is usually applied to "wet" or "drip." Nozzles on the
boom or handheld gun break the spray into small droplets and direct it to the
foliage.
II) Low Volume Sprayers:
Since in these sprayers the spray fluid is atomized with the help of an air stream at
high velocity, they are called mist blowers or power sprayers. The tank in these is
made of a thick polyethylene and has a capacity of 10 liters. The fuel tank capacity
is 1.0 to 1.5 liters. It is provided with 1.2 to 3.0 hp petrol engine. This can also be
used for dusting provided suitable accessories. The area covered by these sprayers
is about 2 ha in a day.
III) Ultra Low Volume Sprayers:
The pesticide in ULV formulation is used undiluted at a quantity less than 6 liters/ha
and usually at 0.5 to 2.0 liters/ha for field crops. The droplet size varies from 20-
150 micron with ground spraying equipment for ULV spray an area of 5 ha can be
covered in a day.
2. Dusters
The desired effects of a pesticide can be obtained only if it is applied in an
appropriate time and in a proper method. The important methods of applying
pesticides are dusting and spraying. The appliances that are used for applying
dust and spray formulation of pesticides are called dusters
All dusters consist essentially of a hopper which usually contains an agitator, an
adjustable orifice and delivery tubes. A rotary fan or a bellows provides the
conveying air.
1. Plunger Duster: It is simple in construction and consists of a dust chamber, a
cylinder with a piston or plunger, a rod and a handle. It is useful for small scale use
in kitchen garden and in household.These dusters can carry 2-2.5 kg dust and it
covers 0.5-1 ha /day.
· 2. Bellows Duster: It has a pair of bellows made of leather, rubber or plastic. The

12. bellows can be worked with a handle just like a Blacksmith does. The dust is
placed either in the bellows or in a separate container made of wood, metal or
plastic attached to one end of the bellows. The air current that is created runs
through the container and drives the dust out through an opening. Hand held
bellow duster has containers of capacity from 30 g to 500 g.
· The bellows can be operated either directly by hand or by handle provided for that
purpose.The knapsack duster has the container capacity of 2.5 to 5.0 kg.and it
covers 0.5 – 1.0 ha/day
3. Hand Rotary Duster: They are also called crank dusters and fan type dusters.
They may be shoulder mounted, back or belly mounted. Basically a rotary duster
consists of a blower complete with gear box and a hopper with a capacity of about
4-5 kg of dust. The duster is operated by rotating a crank and the motion is
transmitted through the gear to the blower. The air current produced by the blower
draws the dust from the hopper and discharges out through the delivery tube
which may have one or two nozzles. It is used for dusting field crops, vegetables
and small trees and bushes in orchards. The efficiency of these dusters is 1 to 1.5
ha/day.
Uses of spraying and dusting equipments
· The spraying and dusting equipments are used for the following purposes
· For the insecticides application to control insect pests on crops and in
stores, houses, kitchen, poultry farms, barns, etc.
· For the insecticides application to control insect pests on crops and in
stores, houses, kitchens, poultry farms, barns, etc.
· For the acarices application to control phytophagous mites.
· For the fungicides and bactericides application to control the plant diseases.
· For the herbicides application, to kill the weeds
· For the harmone sprays application to increase the fruit set or to prevent the
premature dropping of fruits.
· For the application of plant nutrients as foliar spray.
· For applying the powdery formulation of poisonous chemicals on the crops
and for any other purposes.