7///4 exm Flashcards
One of the major operations in any crop production system is the caring of crop to protect the plants from__ or __ so as to get _____ yield.
any pests or disease infestations
maximum
is the process of
providing plants the conditions that will
make them free of weeds, pests and
diseases.
crop protection
are plants that grow side by side
with the main crops.
weeds
are considered unwanted plants
since they are nuisance to the growth of
crops.
weeds
On the other hand, pests could either be
__ , ____ or ___ that are also
detrimental not only to crops but also to
humans.
plants, animals or viruses
In the phenological stages of crop, the ___stage
between___ and ___ constitutes the longest stay of crops in the field.
_____ ; planting and flowering
This is also the most vulnerable period for the crop to
get diseases.
the growing stage
between planting and flowering
Weeds compete with the crops for (5)
- available light
- moisture
- space
- nutrients
- if left uncontrolled pests and diseases can
multiply above the economic threshold
7 Methods of controlling pests:
Cultural control
ecological contro;
biological
physiological
chemical
flame control
mechanical control
–this is the application and
management of pests by manipulating the environment
or implementing preventive practices such as using
plants that are resistant to pests, proper timing of
planting and crop rotation.
Cultural control
this involves the changing of the
crop and the pests’ environment that favors the survival of
the crop such as flooding to kill insects and weeds.
Ecological control
this is the introduction of
certain insects which feed on pests, application
of chemosterilants to render the male sterile, or
planting of certain plants whose odor drive pests
away.
Biological control
this is the breeding and
planting of pest resistant varieties.
Physiological control
it involves the application of
chemicals to control weeds, pests and diseases.
Chemical control
the use of flame for the selective
burning of weeds in crops whose stem is not
injured by a short exposure to intense heat.
Flame control
the use of tools, implements and
machines to reduce or eliminate weeds and insects
such as in land preparation, cultivation and weeding.
Mechanical control
is important and significant to minimize if not totally
eradicate crop diseases , insects and weeds to avoid crop losses
Chemical control
The world consumption of around ___ of pesticide was
estimated for 2020
3.5 million tons
to have an advance plant prtection, we need three
Efficient pesticide
advanced machinery
Advance application technology
The pesticide development trend :
Pesticides are grouped according to the types of pests they can
eradicate:
- insects
- plants
rodents (rats and mice) - (Mollusk)
- bacteria
- fungi
- larvae
Insecticides - insects
Herbicides - plants
Rodenticides - rodents (rats and mice)
Molluscicide - (Mollusk)
Bactericides - bacteria
Fungicides - fungi
Larvicides - larvae
The pesticide development trend :
Production amount ___
decreases
used to eliminate a variety of insects/
pests and diseases including those beneficial to
the environment.
sprayer
Eliminates pests and
diseases including beneficial insects/plants aside from the target pests.
Broad-spectrum pesticides.
The pesticide development trend (2)
High efficiency
Low toxicity &residual
The application technology trend for spraying: 3
➢ improve rate of pesticide utilization
➢ high control effect
➢ reduce amount of chemicals that may contribute to
pollution to the environment, food , water.
The machinery trend for sprayers 5
✓ intelligent target sprayer,
✓ electrostatic sprayer,
✓ recycling sprayer,
✓ wind assisted sprayer,
✓ aerial(UAV) plant protection.
4 stages in Development of Agriculture
primitive
traditional
modern
ecological
simple farming with rough stone ,clubs as the tools , the initial
stage of farming.
Primitive agriculture:
use of manual, animal , hand tools ,iron tools , using the history
of inherited farming methods, cultural practices and
technology.
Traditional agriculture:
Low energy consumption and low pollutions.
Traditional agriculture:
use of machinery, fertilizer, fuel ,electricity , pesticides and other
industrial auxiliaries.
Modern agriculture:
Use of modern technology, management theory , operation methods
for the max production efficiency.
Modern agriculture:
based on the ecology and natural laws, under the premise of
protecting and improving the ecological environment, using
systematic engineering methods and modern and advanced
technologies
Ecological agriculture:
4 application of technology development
natural
large capacity conctrol
sustainable control
pollution-free control
4 machinery development in sprayer
human - artifical splashinh
manual sprayer - manual, compress. tube, pedal
powered sprayer - powder sprayer, boom sprayer
aerial sprayer, static electricity sprayer
Improving the cultivation and farming system, pests and
diseases are controlled through managing the farmland by
water conservation and farming technics
effective, safe, economic, but often dependent to the__, ___ and ___
Agricultural science and technology
time,
location and seasonal restrictions.
Beneficial microorganisms are used to eliminate or
suppress the occurrence of pests and diseases
Biological control
- Use of temperature, ray and other physical factors.
- Seeding & soil heat treatment & radiation treatments
- Effective, but the operations usually complex.
- Good values for no environmental pollutions.
Physical control
- Use chemical pesticides to control pests and diseases
- Stable and rarely subject to the geographical and seasonal restrictions.
- Mechanized spraying can be used to improve the operational efficiency
and the ability to cope with sudden change, - Can be applied in large area of pests and diseases.
- Less pollution risk if use properly.
chemical control
- ____ is still the main method of crop protection
commonly practice worldwide. - Applying chemical pesticides using machinery is to improve the ___ and ___ of spraying operation.
- Advance technology and machinery could (3)
Chemical control
efficiency and effectiveness
improve the control effect
efficiency of application
reduce the residue and pollution
Chemicals are usually applied using ___sprayers. They
are primarily used for the application of herbicides, insecticides,
fungicides and plant nutrients.
mechanical
___ can come in different
types and sizes from man-
portable units such as backpack
type with spray guns to self-
propelled units with mounted
booms
Sprayers
3 Basic functions of a sprayer.
- to break the liquid into droplets of effective size.
- to distribute the spray solution uniformly in the
point of application - to regulate the rate of application during spraying
operation.
5 basic components of sprayer
Tank
Pump & pressure chamber
Nozzles
Cut-off valve
Flexible hose and rigid lance
functions of the basic components of the sprayer
- Chemical supply : Tank
- Energy source : Pump & pressure chamber
- Atomizer : Nozzles
- Control device : Cut-off valve
- Conductors : Flexible hose and rigid lance
2 Classification of sprayers
hand operated sprayers
power operated sprayers.
Hand operated sprayers could
either be (2)
a knapsack type of
compressed air type hand
sprayers
8 Classification of Power operated sprayers
knapsack type,
portable type,
ultra low volume (ULV) sprayer,
self propelled type,
travelling type (mounted or trailer),
agricultural robotic sprayer,
boom sprayer,
aerial sprayers.
Basic Parts of a
Knapsack Sprayer PAES #
PAES 112:2000
are devices to control the fluid flow that exits or enters an enclosed
chamber or pipe via an orifice.
nozzles
They are pipe or tube of varying cross-sectional area and used to direct or
modify the flow of fluids.
nozzles
They control the rate of flow, speed, direction, mass, shape, and/or the
pressure of the stream that emerges from them.
nozzles
They atomizes the liquid to fine particles by the application of high pressure.
nozzles
4 Classification of Spray Nozzles
According to the number of nozzle holes:
According to the number of nozzle head:
According to nozzle shape
According to spray pattern
2 Classification of Spray Nozzles
According to the number of nozzle holes:
single hole
multi-hole nozzle
one hole on a nozzle tip
on top of a spray rod
Single Hole Nozzle-
many holes on a nozzle
tip on top of a spray rod
multi-hole nozzle
2 Classification of Spray Nozzles
According to the number of nozzle head:
single head nozzle
nulti head nozzle
a head on a nozzle
body at the top of a spray rod
Single head nozzle
comprise of two or more head on a nozzle body on top of a
spray rod.
Multi-head nozzle
Classification of Spray Nozzles
According to nozzle shape 3
Tip Nozzle
Disc Nozzle
Cap Nozzle
2 Classification of Spray Nozzles
According to spray pattern
cone type
fan type
– produces a cone shaped pattern of
spray which could be hollow or solid cone
cone type
This type is best suited for spraying crops because it
produces a spray in which droplets approach the leaves
from several angles.
cone type
It operates in high pressure and requires small orifice
opening.
cone type
produces a flat pattern and is best
suited for spraying flat surfaces as in the application
of herbicides
fan type
It operates in low pressure and requires a large
orifice opening.
fan type
The performance of the nozzle is dependent on hydraulic energy
as follows:
The higher the pressure, the ___ the droplets
The higher the pressure, the ___ the flow rate
The higher the pressure, the ___ the spray angle
smaller
higher
wider
Principles of Creating Hydraulic Energy
Pressure is created by adding ___ to the chamber with a fixed
____ of liquid (___ sprayer)
air
volume
compression
Pressure is created by adding ___ to a chamber with fixed
volume of ___(___ sprayer
liquid
air
knapsack
Application Methods 5 for spraying
➢ Spraying application method
➢ Powder spraying application method
➢ Mist spraying method
➢ Ultra-low-volume spraying method
➢ Smoke spraying method
is the main method for crop diseases, insects and
weeds control
Spraying application method
Under the action of a certain pressure, the liquid droplets sprayed out through
the atomization devices(nozzles) with ____ in diameter.
150-400um
1 advantage and 2 disadvantage of
Machines/Equipment:
- Manual sprayer
- Motor sprayer(carrying, stretcher, cart, boom).
Advantages: high operation efficiency to adapt to a wide range of application.
Disadvantages: high water consumption as solvent
high power consumption
Refers to use the high speed air to blow out the liquid, then
impact on the air to form small droplets attach to the crops
with 50-100um in diameter.
Mist spraying method
mist spraying method is also sometimes called __ sprayer (____)
Sometimes called fog sprayer(knapsack).
2 advantage and 3 disadvantages of mist spraying method
Advantages: simple operation, cheap.
Disadvantages: drift, noisy, high labor requirement.
Use of high pesticide concentration and by centrifugal force, the
liquid are scattered into tiny droplets with 70-300um in diameter.
Ultra-low-volume spraying method
Ultra-low-volume spraying method is usually used for ___ spraying
aviation
2 advantage and 2 disadvantages of ultra low volume sprating method
Advantages: high efficiency, 80-100 times of ground sprayers.
Disadvantages: high drift formation, needs professional operators.
diameter range of the ff:
atomization devices (nozzles)
mist sprayer method
ultra-low-volume spraying method
150-400 um
50-100 um
70-300 um
Use high speed of airflow to blow
the powder to the crop.
powder spraying method
2 advantage and 1 disadvantage of power spraying method
Advantages: high efficiency and
easy operation
Disadvantages: large drift
impacted by the wind.
Use of high-speed rotating air to form the liquid to
20um droplets ,then blow out.
smoke spraying method
smoke spraying method is usually used in
The method is usually use in enclosed space
(Green house).
1 advantage and disadvantage of smoke spraying method
Advantages: good adhesion and effect because very fine droplets.
Disadvantages: enclosed space.
6 application techbology for spraying
- Target spray technology
- Electrostatic spray technology
- Air-assisted spray technology
- Droplet controlled technology
- Low-volume spray technology
- Recycling spray technology
2 categories for target spray technology anf their descriptiom
save pesticide __ to __%
Image recognition: high
image quality , expensive.
- Echo recognition: usually ultrasonic
on the target echo to identify the
target
50-80%
- Droplets charged by high-voltage electrostatic generator;
- Depositions at the back of the leaf,the middle and lower parts of the crops _____;
- Can save pesticide ___
electrostatic spray technology
increases
30-40%
Additional wind turbines or airbags; With the force of turbines or airbags assisted, the
droplets penetrated well;
Especially when the wind speed is bigger than
__m/s.
Can save pesticide ___
air-assisted spray technology
5
40-70%
Technology that retrieve pesticides not targeted on
the crops which are recycled;
Can save pesticide __.
recycling spray technology
90%
9 application machinery in spraying
➢ Manual sprayer
➢ Motorized sprayer
➢ Efficient wide rang long distance sprayer
➢ Wind-type sprayer
➢ Boom sprayer
➢ Aerial unmanned aircraft vehicle
➢ Fixed wing aircraft;
➢ Rotary wind aircraft(UAV, Unmanned aviation vehicle);
➢ Operation/ manipulation: manned, unmanned
____ has higher liquid volume capacity compared with the unmanned rotorcraft
➢ With high efficiency spray
operation but high risk for ___
➢ High operating altitude, large
droplet drift distance; needs
landing site and other restrictions.
Fixed wing aircraft
disasters
Fixed wing aircraft man-operated
High fluid volume carrier
High spraying efficiency for (2)
Large drift because of __ operation
Need for ____.
➢ Contiguous large area
➢ Locust control operation.
high altitude
landing site
➢ UAV
➢ Operational altitude is relatively ___ with __drift
➢ No ___ and ___
➢ The downward airflow produced by the rotor helps to ___the penetration
low ; less
special takeoff and landing airport;
increase
Enter the area which is inaccessible to the
ground machines. No tire tracks, no damage to the crops. For mixed farming area of civil houses and fields.
Broad Adaptability
is one of the most important crop protection
operations in crop production systems.
weeding
are serious threat to agricultural crops since they can
enhance the proliferation of pests and diseases
weeds
- In lowland rice production system, weeding is usually done
_ to _ weeks after transplanting to retard the growth of weeds
and is repeated - weeks after the first weeding.
1 to 2
2-3
Weeds are classified as (3)
annuals, biennials and perennials.
weeds, which complete their life cycle in a year,
propagate through seeds.
annual weeds
They are less difficult to control since they depend on seeds to
multiply.
annual weeds
The most appropriate mechanical control is through cultivation
before the weeds reach the ___stage.
seeding
Moreover, the most effective control of annual weeds is through mechanical means in combination with other __, ___ and other soil and water management practices (Pathak, 1979 as stated in ESCAP- RNAM, 1983).
biological, chemical
- ___weeds are neither important nor common.
- ___weeds are very common and they are difficult to control.
- Perennial weeds are propagated by __ or __
Biennial
Perennial
seeds or through their
vegetative parts.
- The principle of weeds elimination before ___stage is
encouraged so as to avoid proliferation of weeds. - Once the weeds emerged from the __, it would be harder to control.
- Weeds could be eradicated mechanically by ___
during the dry season to expose the ___. This method will work if
the cultivated area remain dry for a long period.
seeding
soil
turning over the soil
roots
2 classification of weeders
a. by design of soil working part
b. by power source
3 classification of weeders by design of soil working part
blade
tine
rotary
these are weeders having rectangular, triangular and crested
shapes with cutting edges sharpened and hardened for soil cutting and weed
uprooting.
blade type
are weeders with straight or curved, round or
square cross-section steel rods sharply pointed and hardened
at the soil working end.
tine type
are weeders with curved spikes or paddles
attached radially to a common axle which rotate when pushed
forward to uproot and bury weeds
rotary type
are either hand- held or push-type
weeders for upland or lowland farming conditions.
manual weeders
are those that utilize either the
blade and tine type of soil working parts with short (< _m),
medium (<__ m) and long (> _ m) Handles
hand held weeders
0.5
1
1
are those that utilize any
of the three types of soil working parts for lowland (___ weeder) and upland (___) weeding
push type weeders
rotary
wheel hoe
are weeders with soil
working parts mounted on a frame or tool bar
pulled by an animal for upland weeding
animal-drawn weeders
are rotary type weeders
driven by engine for lowland weeding
power weeders
have soil working
parts mounted on a frame or tool bar pulled by
a two-wheel or four-wheel tractor for upland
weeding
tractor-drawn weeders
is the ratio between the number
of weeds removed by the weeder to the number present in a unit area
expressed in percentage.
weeding index (e) or weeding efficiency
weeding index (e) formula
e = (W1-W2)/W1 x 100
where :
W1 is the number of weeds before weeding
W2 is the number of weeds after weeding
is the percentage of plants
injured during the weeding operation
percent damaged plants (PDP)
formula for percent damaged plants (PDP)
PDP=d/q x 100
where : q is the number of plants before weeding
d is the number of damaged plants after weeding
describes the performance of the weeder
Performance Index (PI)
_____ is the measure of the performance of the weeder that is directly proportional to the __ per unit __,
the weeding index and the quality of work (undamaged plants) are ____ to the power required
performance index
area per unit time
inversely proportional
Performance index formula
PI = (C x (100-PDP) x e)/P
where : C is the actual field capacity, ha/h
PDP is the percent damaged plants, %
e is the weeding index, %
P is the power input, hp
For practical purposes, power input can be assumed as ___ for human power and __ for animal power.
0.1 hp
1.0 hp
For a given sprayer, the following factors should be determined: 4 and their units
Nozzle discharge at different pumping rates (L/min)
Effective working width or swath (m)
Walking speed (m/min)
Application rate (L/ha)
PH is a __largest archipelagic nation in the world and a major __ production country
Second
fish
Total production = ____
of fish, crustaceans, mollusks and
other aquatic animals
3.1 million tonnes
Aquaculture = about ___tonnes
(__%) contribution to the total fish
production
Seaweeds production = ___
790,900 ; 25.4
1.8 million tonnes
RA ____ or ___
purposive acceleration on the
diffusion, adoption and utilization
of Agricultural and Fisheries
Mechanization Technologies
(AFMTs).
10601 (AFMECH Law of 2013)
classifications for
marine (4)
inland (3)
MARINE
- fish marine pelagic
- mollusc cephalopods
crustaceans
aquatic plant
INLAND
- fish
mollusc- bivalves
crustaceans
process flow operation for marine and inlad captured fisheries
harvesting –> storing –> sorting –> primary processing –> marketing
(Including transport of
fishing vessel from the
shore to the fishing
ground and vice versa)
harvesting
(Storage of catches
to maintain
freshness while at
fishing ground)
storing
(sorting of
catches by
species or by
size)
sorting
5 Fish Ports
1.Navotas Fish Port Complex
2.Lucena Fish Port Complex
3.Davao Fish Port Complex
4.General Santos Fish Port Complex
5.Feeder Ports
3 institutions related to disheries
- SEAFDEC -Southeast Asian Fisheries Development Center
- BFAR Regional Offices- Bureau of Fisheries and Aquatic Resources
- LGUs – Local Government Units
best practices for LGU BFAR for production (3)
zoning (2)
environment (5)
management & monitoring (2)
Production
* Anti-poaching
* closed season for fishing
* cage stock limits
Zoning
* Sanctuary zones
* Seaweed production zone
Environment
* Proper disposal of fish kills
* Environmental Compliance Certificate (ECC)
* neutralize water before draining
* use of tea seed as substitute for cyanide
* overfeeding prohibition
Management & Monitoring
* registration of seaweed growers
* registration of boats
best practices for LGU BFAR for
protected area (1)
protected species (endangered species 11
prohibited fish gears 8
smalle net number prohibited for
Laguna
in some places
Zambales
Protected area
* Most sites have protected areas
Protected species ( endangered species)
* turtles/pawikan
* sting rays
* small fish
* spawning crabs
* eels
* dolphins
* sharks
* aquarium fish
* bulaw
* hasa
* taclobo
Prohibited Fish Gears
- dynamite
- small nets
(#11 in Laguna, #5.5 in some places, #14 in Zambales) - compressor set for diving method of catching
- poison/cyanide
- trawl/baling
- triple net
- fish pens in brackish water (Pampanga)
- electro fishing
FMTs are focused on __ and __
FMTs are focused on fishing boats and prime movers
__ used are mostly manual
Fishing gears
__, __< and __ are the
common sources for lighting
Kerosene, lead acid battery and generator
- Majority of the fishing vessels and prime movers are
___ (the size of engine is small in
comparison to the length of boat)
mismatched
- Fishing vessels of small fisherfolk are measured in
terms of ____and not by ___
length
capacity
- For marine aquaculture, FMTs are focused on ___
- For inland aquaculture, FMTs are focused on ___
fishing boats
water pump
Benchmarking with other countries in the ASEAN region
____ - top producing for
fish and fishery products
___ - 5th top producing country in the ASEAN
____ - highest number of
fishers in aquaculture
Indonesia
Malaysia
Singapore
indicative measure of the level of mechanization
Fisheries Mechanization Index – FishMI
7 Parameters
Considered for the
FishMI
type of power
source
energy value of the
fish species or
seafood category
average growth period
of the cultured fisheries
in aquaculture
number of operators
involved in certain
activities
average duration of
stay in the fishing
ground for marine
and inland captured
fisheries
The level of fisheries mechanization shall be determined in
terms of energy ratio through the Fisheries Mechanization
Index (FishMI) general formula
energy ratio = energy output/energy input
The level of fisheries mechanization shall be determined by
category by region
(2)
The national level of fisheries mechanization will be presented
by the lowest and highest energy ratio among the regions.
Category 1: Marine and Inland Captured Fisheries, and
Category 2: Aquaculture
The standard size of municipal fishing vessel:
The standards for municipal fishing vessel or fishing boat of ___ and below and the recommended e____ for
specific municipal vessels/fishing boats should be established.
There is a need for harmonization of policies among the agencies
implementing fishing ground regulations, at the national, regional,
provincial and up to the municipal level.
three (3) gross tons
engine power rating (hp)
Mechanical device used for transferring
fluids from one place to another
water pumping equipment
The source of fluid is usually of ___ elevation than the point of delivery
lower
Source of water are usually (5)
wells, rivers,
lakes, reservoirs and canals
___are essential for good health and
sustained agricultural production
Pumps
Pumps are either ___ (“poso”) for domestic water supply or __ (deep well) for both domestic and irrigation purposes.
hand-operated
power-operated
6 benefits of irrigation
- increased cultivated area
- improve crop yield over rainfed
- allow greater cropping intensity
- improve economic security for the farmer
- reduce drought risk
- allow introduction of more valuable crops
The parameters that must be determined to size a pump are: 2
- discharge capacity (Q)
- total head (H)
is the volume of water delivered or pumped per unit of
time expressed in volume of water per unit time
discharge
is normally dictated by the
requirements of the system in which the pump is located.
required capacity of the pump
height of a vertical column of water. It is the
quantity used to express a form (or combination of forms) of
the energy content of the water per unit weight of the water
referred to any arbitrary datum.
head
Pressure and head are interchangeable concepts in irrigation,
because a column of water ___ feet high is equivalent to 1 pound
per square inch (PSI) of pressure.
2.31
The total head of a pump is composed of several types of head. The total dynamic head of a pump is the sum of the total (4) head
static
head, the pressure head, the friction head, and the velocity head.
is the total vertical distance the pump must
lift the water.
total static head
The distance from the pumping water level in the well to the
ground surface plus the vertical distance the water is lifted from
the ground surface to the discharge point.
total static head
The total vertical distance from the water surface to the
discharge point.
total static head
The pressure head at any point where a pressure gage is
located can be converted from pounds per square inch (PSI)
to feet of head by multiplying by ____
2.31
is the energy loss or pressure decrease due to
friction when water flows through pipe networks.
friction head
is the sum of all the
friction losses. Values for these losses can be calculated or
obtained from friction loss tables.
friction head
is the energy of the water due to its velocity.
velocity head
This is a very small amount of energy and is usually negligible
when computing losses in an irrigation system.
velocity head
A pump operating above a water surface is working with a
____head.
suction
suction head includes not only the vertical suction lift, but also
the friction losses through the (4) on the suction side of the pump.
pipe, elbows, foot valves and other fittings
There is an allowable limit to the suction head on a pump and the ___ of a pump sets that limit.
net positive suction head (NPSH)
- The theoretical maximum height that water can be lifted using suction is ____
33 feet.
are the one that discharges the same
volume of water regardless of the head against which they operate.
Positive displacement pumps
have the characteristic of
which the discharge and head have inverse relationship. High
head will result in ___discharge and vice versa.
Variable displacement pumps
low
2 Main parts of a variable displacement pump and element
- a rotating element, including an impeller and a shaft,
- a stationary element made up of a casing, casing cover, and
bearings
3 Classification of pumps according to the direction of flow
leaving the impeller with respect to the shaft direction.
propeller (axial flow) pump
mixed flow pump
centrifugal (radial flow) pump
It is used for low pressure head and high discharge.
Propeller (Axial Flow) Pump
For drainage pumping and transfer of water from
canals and rivers to adjacent fields.
Propeller (Axial Flow) Pump
The liquid flows from through a propeller type impeller
on cylindrical surfaces concentric to the shaft.
Propeller (Axial Flow) Pump
It combines some of the features of both centrifugal
and the axial flow pump
Mixed Flow Pump
Head is developed partly by the centrifugal force and
partly by the lift of the vanes on the water.
Mixed Flow Pump
The liquid leaves the impeller in a direction diagonal to
the shaft axis on conical surfaces.
Mixed flow pump
is suitable for non-clogging operation.
Mixed flow pump
It is the most used type of pump for
domestic and irrigation purposes.
Centrifugal (Radial Flow) Pump
Centrifugal pump consists of an impeller inside a volute or ____
diffuser casing.
The liquid leaves the impeller
perpendicular to the shaft axis due to
centrifugal force
Centrifugal (Radial Flow) Pump
In a centrifugal pump, the liquid is forced by atmospheric
or other pressure into a set of ___
rotating vanes.
is a wheel or disc mounted on a shaft and
provided with several curved vanes or blades.
impeller
transmits the power from a prime mover (power
source) to the impeller.
shaft
discharges the liquid at its periphery at a
higher velocity.
impeller
This velocity is converted to pressure energy by means of
the
casing
introduces the liquid into the impeller, collects
the liquid leaving the impeller and guides it away under
an increased pressure.
casing
Types of Centrifugal Pumps according to (6)
according to energy conversion
according to number of stages
according to type of impeller
according to type of suctioj inlet
according to axis of rotation
according to method of drive
Types of Centrifugal Pumps
According to number of stages (2)
single stage
multistage
pump in which the head is developed
by a single impeller
single-stgae pump
the total head to be developed requires
the use of two or more impellers
operating in a series, each taking its
suction from the discharge of the
preceding impeller.
multistage pump
Types of Centrifugal Pumps
According to type of impeller (3)
(open, semi-open,
closed)
has no shrouds or side walls
enclosing the waterways. It is used to pump
water with considerable amount of small
solids.
open impeller
is used to
pump water with some amount of suspended
sediments.
Semi-open or semi-enclosed impeller
has shrouds and is used to
pump clear liquid.
Closed impeller
2 Types of Centrifugal Pumps
According to type of suction inlet
(single, double)
has an impeller which has
suction cavity on one side where water can
enter.
single suction
In a single-suction impeller, the liquid enters the
suction eye on ___ side only.
one
has an impeller which has
suction cavity on both sides where water can enter.
double suction
A double suction impeller is, in effect, two single-suction impellers arranged ____ in a single casing.
back to back
2 Types of Centrifugal Pumps
According to axis of rotation
horizontal, vertical
has a vertical impeller mounted on a
horizontal shaft.
horizontal axis type
This is common for centrifugal pumps used for
domestic and agricultural purposes.
horizontal axis type
has a horizontal impeller
mounted on a vertical shaft.
vertical axis type
is common for
pumps in deepwell settings.
vertical axis type
3 Types of Centrifugal Pumps
* According to method of drive
(direct, closed-coupled, belt driven)
the pump is mounted on a base plate
and is connected directly to the driver through a flexible coupling.
direct connected drive
is used wherever there is a need to connect a prime
mover to a piece of driven machinery.
coupling
The principal purpose of a ___ is to transmit rotary motion and torque from one piece of equipment to another.
coupling
Couplings may perform other secondary functions, such as
____ between shafts, compensating for
axial shaft movement, and helping to ____ vibration, heat, and
electrical eddy currents from one shaft to another.
accommodating misalignment
isolate
is built with common shaft and
bearings for the pump and the driver forming a single compact
unit.
close-coupled drive
the pump is provided with a pulley head
for belt drive.
belt driven drive
Sizing of Pumps and Prime Movers:
A criterion that is well accepted in computing the pump capacity is to base it on the highest ___ of the crop.
daily water requirement
The water requirement for rice production is ___ mm/day (NIA)
10
The horsepower needed to drive the pump is computed as follows:
H p = (TDH x Q)/ (3960 x Effs)
Where Q = pump output, gpm
H = total head, ft.
Effs = system efficiency = Effp X Efft X Effpm
Effp = pump efficiency
Efft = transmission efficiency
Effpm = prime mover efficiency
The total head H may be estimated by adding the __ and __ head losses to the total static lift.
friction and velocity
Transmission efficiencies of centrifugal pumps
Water Pumping Equipment
Type of Transmission Efficiency (%)
Direct
Gear
V-belt
Flatbelt
100
98
95
90
the discharge rate of a well per foot
drawdown.
Specific Yield of well
is added to the total head for the computation
of power to drive the pump.
total drawdown
2 Measurement of discharge by container method (PAES 115:2000)
weight method
volume method
This method is preferably used when a liquid’s bubbles are hard to
break. The container shall have a sufficient capacity to prevent the liquid from overflowing
during measurement.
weight method
The weight of the liquid in the container shall be obtained using a
suitable scale at a definite time usually ___ minute.
one
in weight method, The discharge shall be computed using
the formula:
Q= 0.06W/pt
where: Q is the discharge, m3/h
W is the weight of liquid introduced into the container in t seconds, kg
t is the time required to introduce liquid of W, s
ρ is the weight per unit volume of liquid at the
temperature during measurement, kg/L
The container shall have sufficient capacity to prevent the liquid from
overflowing during measurement, and it shall be sufficiently rigid to prevent deformation
when it is filled with liquid. The liquid shall be obtained in a container of known volume for
a definite time usually one minute.
volume method
in volume thod, The discharge shall be computed using the formula:
Q=60V/t
where: Q is the discharge, m3/h
V is the volume of liquid introduced into container in t seconds, m3
t is the time required to introduce liquid of V, s
process of gathering the
useful portion of the crop from the field
harvesting
process of separating the
grains from the straw. Additionally, it
may include cleaning the grains.
threshing
5 System of Harvesting & Threshing
traditional
conventional
mechanical
stripping
combine harvestinh
Cleaning the grains from impurities like chaffs,
empty kernels, and dust is done by manual
winnowing
traditional system
the crop stays longer
in the field due to the extended harvesting and
threshing operations.
traditional system
in traditional system, high field losses ranging from – TO –
5% TO 16%
- _____- most commonly adopted system
_____ - done manually
_____ -done using mechanical threshers.
Mechanical threshers reduces the labor requirement
to about
___man-hours -pedal threshers
__ man-hours per hectare for power threshers
Conventional System
Harvesting
Threshing
100
12
Conventional System
* Cleaning grains by ____ or manually operated ____
- Power threshers with built-in ____ and oscillating ___
reduces the field losses to about __ to ____
winnowing ; winnowers
blowers ; screens
3 to 10
- Mechanical System
Harvesting and threshing is done ____.
Harvesting is done using (3)
mechanically
mechanical reapers,
reaper-binders and reaper windrowers.
- Mechanical System
* Harvesters may be categorized into (2)
- Manually-operated harvesters requires about __ man-
hours per hectare - Power harvesters requires _ man-hours.
- About _ to _ field losses
manually operated and power harvesters.
50
5
3% to 6%
- Combine Harvesting
single machine called ____ performs harvesting and threshing while on the go
combine
Commonly adopted in countries with vast areas planted
with cereal grains.
Smaller combines have been developed for __vgrowing
countries with small farms.
Using a combine may reduce field losses to about __ to __ %, requiring only about _-__ man-hours per hectare of field.
combine harvesting
rice
1.5% to 6%
3-21
This method is also called in-field threshing or simply
stripping and is performed by a machine called stripper
stripping
The ____ is made to pass between two bars of “V”
configuration to separate the grains from the straw.
panicle
Most _____ are equipped with tanks to temporarily store
the harvested grains, or contain mechanisms to
transfer the grains into sacks
Reduce field losses to about __ to __%
strippers
2% to 6%.
7 Factors affecting choice of system
Kind of crop
Timeliness of operation
Topography
Farm size
Type of culture (row or broadcasted,
upland or lowland)
Availability and cost of labor
Availability of capital
A major factor affecting choice of system is ____ of
operation because it affects field losses, time available
for the next crop and grain quality
timeliness
If the crop is harvested too early, it will have a ___
percentage of imperfectly formed kernels.
The field should be drained _-__ weeks before harvesting to harden the soil
large
1 – 1.5
4 classification of harvesting equipment and its subtype
- Hand tools
- Reapers
– reapers
- reaper binders
-reaper windrower - Combines
- Wheel Type
- Track type - Strippers
3 cutting mechanims for harvester
- slicing and tearing actions
- High velocity, single-element, impact action.
- Double-element, scissor-type action.
is attained through the use of sharp,
smooth-edged blades while rough serrated edged
blades are used to perform tearing action
slicing action
are usually employed in
manual harvesting tools like sickles.
Slicing and tearing actions
Portable power scythes and some reapers use this method.
High velocity, single-element, impact action.
A high-speed ____ is used to cut plant materials
rotary saw
A sharp-edged blade runs at about ___ feet per minute for impact cutting while higher speeds are required for dull-
edged blades (about ____ feet per minute)
2,000
9,000
This method employs shearing action
between moving and stationary blades to
cut agricultural crops.
Double-element, scissor-type action.
This is the most common cutting
mechanism used for reapers and
combines
Double-element, scissor-type action.
3 methods of threshing
rubbing action
impact action
stripping action
Threshing occurs when the grains are pressed against the
straws and the threshing floor or mat.
Rubbing action.
The friction created during the process should ____the
force holding the grains to separate the grains from the straw.
exceed
Treading by man, animal or vehicles use this method.
Man treading can produce __ kilograms of grains per hour of
operation
Rubbing action.
14
Mechanical threshers and the “hampasan” employ this method for
threshing grains.
impact action
Threshing occurs when the grains are accelerated faster than their ____. This happens when a force is applied on the crop heads or when
the heads are beaten against a solid object.
panicles
The “hampasan” can have an output of about __ kg/hr of grains. The output
of mechanical threshers varies according to their size and power source
34
Grains are detached from their panicles when the straw
is pulled through a “V” configuration or a comb-like
device or vice versa
Stripping action.
This method is the basic principle governing the
operations of strippers.
Stripping action.
are machines that separate the grains from the
panicles. This function is achieved by employing impact action.
mechanical threshers
modern threshers also perform the following tasks: 3
- Feed the un-threshed grain to the threshing cylinder in an even stream, free from
heavy, solid bunches (Feeding Unit) - Separate the straw from the grain and chaff, and separate the chaff and dirt from
the grain (Cleaning Unit) - Deliver the straw through the stacker to the stack and deliver the grain through
the grain elevator, weigher or stacker to wagon or bin (Stacking and Storage
Unit)
Mechanical threshers vary according to: 4
power source
type of feeding
flow of threshing materials
type of threshing cylinder.
2 Classification of Mechanical Threshers in Power Source
manual thresher
power thresher
Manual thresher rely mainly on ____ effort as power source.
human
These threshers are
powered or driven by engines or in
rare cases, electric motors.
power thresher
Most power threshers require a crew of at least three workers to (3)
feed the threshing materials, collect the grains,
and perform other associated tasks
Classification of Mechanical Threshers based on type of feeding
hold-on feeding
throw-in feeding
the panicles of the cut crop is fed into the threshing
chamber while the stalks are mechanically or
manually held during the operation
Since the straws do not pass through the threshing
section, the machine requires ____ power during
the operation due to the lesser amount of material it
handles.
hold-on feeding
lower
Axial flow threshers use this feeding method. The
grains, together with the straw, are fed into the
machine for threshing
throw-in feeding
Throw-in threshers have heavy-weight
construction and require ____ power due to large
amount of threshing materials they handle.
high
Using this type of thresher
requires that the straws be cut as close to the panicle as possible to lessen the material flow into the machine and for easy grain cleaning.
Throw-in feeding.
Classification of Mechanical Threshers Flow of Threshing Materials 2
tangential flow
axial flow
threshers where materials are fed between the rotating cylinder and stationary
concave and out of the thresher chamber tangentially
About 60% of the grains pass through the ___ and the rest are separated in subsequent operations
Through-flow
concave
Allow the cut crop to move in a helical manner
around the threshing cylinder with a net effect
of moving the threshing materials axially
Since the materials go around the cylinders several times, about __% of the grains are
separated from the straw and passes through the ___
axial flow
90
concave
Type of Threshing Cylinder
Categorized according to the configuration of their “teeth”.
a. Rasp-bar cylinder.
b. Peg-toothed cylinder.
c. Wire-loop cylinder.
bar-like protrusions in parallel orientation are laid in the periphery of the cylinder
Rasp-bar cylinder.
adopted for a wide variety of crops like peanut and other cereal
crops because of its “mild” action.
Rasp-bar cylinder.
it is also recommended for high-moisture threshing in straight-
through combines
Rasp-bar cylinder.
This cylinder is equipped with spikes or
pegs on its periphery in tandem or helical
arrangement
b. Peg-toothed cylinder.
This is the most common cylinder used by
axial flow threshers for rice.
b. Peg-toothed cylinder.
In this threshing cylinder, wire loops of
the same size and arc are attached on
the periphery of the cylinder in tandem
or staggered arrangement
Wire-loop cylinder.
