Thursday, January 17, 2019
Horticultural Machineries Essay
Horticultural machinery argon the versatile tractors, set agriculturists, drills, scatterers, nail down vegetable harvesters and opposite equipment of interest to horticulturist POWER UNITS USED FOR horticultural PURPOSES The occupy for supererogatory types of indicant unit and or cultivation implements arises when it is undeniable to work between proceedss trees or halyard, where the dressing distance has already been indomitable and the equipment has to con engineer to it. particularise rows of harvest-feasts and haps or so judgment of convictions necessitate the using up of extremely narrow tractors, with over wholly widths of ab break 4 ft (1. m) such tractors require especially adapted mounted equipment and drug abuse among other implements, types of work which argon intentional for plugging up or a reachice from both sides of rows of haps or fruits some of special cultivation implements use include. 1. SMALL ROTARY CULTIVATORS A rotary grower is a excess ivelyl that is used to loosen, ae localize and prep atomic offspring 18 reproach for smart planting or to enhance the condition of territorial dominion for existing plantings. A rotary agriculturist often cognize as rotatiller or roto cultivator consists of sharp rotating tins or blades that ar typically made of steel or aluminum.The rotating tins dig into the shite, defecation and ae valuation the soil in a military operation k immediatelyn as cultivation. Cultivating soil is principal(prenominal) because over a period of time soil tends to urge and harden. This loafer make it more unmanageable for plant to receive the proper tell of peeing and nutrients. Breaking up and loosening compacted soil makes it easier for pee supply and nutrients to f minuscule done the soil and into plantings. A baseborn rotary cultivator is hand held cultivator either self propelled or supply. It looks much like a lawn mower.A self propelled rotary cultivator has tins (blades) attached to a pole that is similar to a long sit and the user simply pushes it to cultivate a lawn or garden. Many self propelled cultivators fill aluminum tines which some users guide found to be too light lading for anything more than light grader use. There be consequently self-propelled cultivators that utilize a heavier angle metal for the rotating tines, which many summon to be more effective. However, the heavier weight of these tools may make it more difficult to use for an extended period of time.A repelized cultivator is powered by a lesser foul upoline or electric motor it is often used on large gardens. The tines of a rotary cultivator circumvolve in the opposite direction of the wheel and till to a attainment of 8 to 10 inches normal width of the small rotary cultivator range from 4 8 ft (2 2. 4m) with power rating ranging from 1 hp to 8 hp (0. 75kw) 2. WALKING TRACTOR The walking tractor or two-wheel tractor is a tractor with ace axle self powered and s elf-propelled which can pull and power various farm implements such as a tractor, cultivator, or harrow, a move around or various seeders and harvesters.The operator ordinarily walks behind it or sides the implement being towed like a four-wheeled tractor, the walking tractor is designed to run many attachments with a single power source and gives thousands of hours of services. These tractors ar fitted with engines of up to 3hp (2. 2 kw). near walking tractors now constructed have a power rating of up to 12 hp. 3. concentrate TRACT TRACTOR Narrow track tractors are of interest to horticulturalist who frequently need to pull a heavy nebuliser machine as wellhead as to take on show up plugging and other tillage operations.Such tractors with engines of 25 45 hp (19 33 kw) may have overall dimensions as small as ab pop out 1m wide as 1. 3m lofty. They are fitted with 4 tyres and articulated frame steering of a type that can erect a rattling small turning circle, they hav e low weight to permit work beneath trees. Hydrostatic transmission assists in achieving a sound method of delivering power to the drive wheels. 4. COMPACT L-WHEEL TRACTOR A compact utility tractor (CUT) is a smaller version of an pastoral tractor designed primarily for landscaping and use in region with narrow spaced tracks. representative CUTs range from 20 50hp (15 -37 kw) with available PTO horse power ranging from 15 45 (11 -34 kw) CUTs are often equipped with both a mid-mounted and hackneyed rear PTO, especially those below 40 hp (30 kw). modern CUTs use hydrostatic transmissions notwithstanding many variants of gear-drive transmissions are overly offered from low priced, aboveboard gear-transmission to advance glide-shift transmissions. CUTs require special smaller implements than full surface of itd agricultural tractors. Very common implements include, the box blade the grader blade, the landscape rake, the post gob digger, the rotary cutter, a broadcast seeder, and a rotary tiller.SOIL market-gardening IMPLEMENTS 1. PLOUGH The black Maria is a tool used in kitchen-gardening for initial cultivation of soil in preparation for sowing seed or planting. It has been a basic instrument for more or less of recorded history and represents one of the study advances in agriculture. The primary purpose of plugging is to turn over the speeding layer of the soil, bringing fresh nutrients to the surface d apple burying weeds and weed seeds, allowing them to breakdown. It also aerates the soil, allows it to hold moisture better and provides a seed-free strong suit for planting on alternate train. The plough is made up of the pursual components . The Coulter The function of the coulter is to cut the soil. It is this component of the plough that clears the path. The coulter is a blade or sharp-edged disc attached to a plough so that it cuts done the soil vertically. 2. The Mold Board It is the part of the plough which pushes aside the soil, tur ned over by the coulter. It is either rounded, helical, helically cylindrical or a curved rod. 3. Plough-Beam The part that connects the rest of the plough with the animal or tractor. Its shape and length in labial pipences the depth of the coulter and to a lesser effect ts width. 4. Plough Share The plough-share is the fundamental part of the plough on which the other major move are fixed (plough-beam, mold boards coulter, contre-sep). 5. Contre-sep Allows the stabilization of the plough temporary hookup swearing the hilt. Any standard steel can be used for its construction. 6. The Hilt Permits the longitudiral stabilization of the plough pliding on the bottom of the trench longitudinal stability is ensured by reaction between the ground supports on the soil, the support points on the strawman and the rear of plough and by the wheel. SOIL sterilisationSoil sterilization is a chemic or physical litigate that results in the death of soil organisms. This practice provides sec ure and quick eternal rest of soil from substances and organisms harmful to plants such as bacteria, viruses, kingdom Fungi, nematodes and other pests. Many of the organisms in the soil helps breakdown larger pieces of organic matter into small particles which are more intimately absorbable by plants but they could be in the soil detrimental fungi, bacteria and insects and weed seeds. Soil sterilization helps to do away with these detrimental organisms and seed weeds.There are two major methods of soil sterilization Chemical method and physical method. 1. Chemical methods includes the use of herbicides and fumigants 2. Physical methods include the use of travel and solar zippo a. go sterilization Soil move is a farming technique that pay offs soil with locomote in open fields or chiliad houses. pernicious organisms and weeds are killed through induced hot travel which causes their jail cell structure to physically degenerate. Biologically, the method is considered a pa rtial tone disinfection. Important affectionateness-resistant, spare-farming bacteria survive and revitalize the soil after cooling down.Steaming leads to a streng thuslyed resistance against plant disease and pests. METHOD OF locomoteING 1. open muggy it is the practical application of screw up directly on the surface of the soil using various methods which include land sheet traveling, the steaming hood, the steaming harrow, the steaming plough and inanity steaming with drainage pipes or officious pipe system. i. Sheet steaming Surface steaming with special sheets is a method which has been established for decades in other to steam large domain of a functions arrival from 15 to 400m2 in one step.The usage of genus Oestrus resistant, non-decomposing insulation souse saves up to 50% energy reduces the steaming time significantly and improves penetration. The drift time depends on soil structure as well as outside temperature and amounts to 1 1. 5 hour per 10 cm ste aming depth. ii. Steaming with Vacuum This is induced through a mobile or fixed installed pipe system in the depth of the area to be steamed. It is the method that reaches the best penetration. Despite high capital cost, the fixed introduction of drainage system is reasonable for intensively used areas since steaming depth of up to 80 cm can be achieved.The steaming area is cover with a special steaming sheet and weighted all around as with sheet steaming. The steam is injected lowneath the sheet through an injector and protection tunnel while with short areas up to 30m length steam is frontally injected, with longer areas steam is induced in the middle of the beetroot using a T-connection branching out to both sides. As in the beginning long as the sheet is inflated to approximately 1m by the steam coerce, the sucking turbine is switched on. First, the transfer in the soil is shiftd via the suction hoses. A vacuum is formed and the steam is pulled downward.When the required steaming depth has been reached, the ventilator runs non-stop and surplus steam is blown out. To ensure that, this surplus steam is not lost, it is provide back under the sheet. iii. Steaming with hoods A steaming hood is a mobile whirl consisting of corrosion resistant fabrics such as aluminum, which is position down on to the area to be steamed. In contrast to sheet steaming, cost-intensive work steps such as lying out and system of weights the sheet dont occur, however the area steamed per on the job(p) step is smaller in accordance to the size of the hood. . SOLARIZATION solarisation of soil is a much more non- chemic environmentally friendly way of soil sterilization and this involves using the power of the sun to get liberate of many disease and pests that causes reproach to different types of grasses. It is a relatively flourishing method of sterilization and involves covering up the soil that will be established with a clear plastic material to capture the radiant heat and energy from the sun to kill the pathogens in the soil.Not totally does this method get rid of most of the unwanted diseases and pests but it also stimulates the relense of nutrients from organic matter present in the soil. c. ELECTRIC SOIL autoclave The electric soil sterilizer is often used for sterilization of small quantity of soil needed for the nursery or in green houses. The equipment is make full to the top of the container and then the unit is plugged in. the thermostat is then set to the correct sterilizing temperature (about 80c). The indicator light will shining until the batch is done.After the light goes off, wait 15 minutes, then hen-peck up the unit and the sterilized soil will drop out the bottom. It eliminates weeds and disease, kills weeds practically 100% kills soil-borne insects and in general, all of the bacteria, fungi and virus organisms that are harmful to commercial primps. d. CHEMICAL SOIL STERILIZATION Chemical sterilization of soil refers t o the use of various chemical to sterilize soil. The chemicals to be used must give off botch which is sufficiently toxic to ensure the destruction of pest, diseases and weeds, yet without harming the beneficial, organisms in the soil.The efficiency of chemical sterilization varies greatly, not because of precise chemicals involved, but because of the condition of the soil, its moisture core and most importantly, the prevailing temperature. This should also ensure as yet distribution in the soil to be sterilized some chemicals used for soil sterilization include 1. Methyl bromide gas Methyl bromide is a fumigant that is most often used in vegetable and farm production. It is unremarkably applied s gas injected into the soil and then covered by a thin plastic shield in order to torpid the movement of methyl bromide from the soil to the atmosphere in that proper(postnominal) area.It is a dangerous chemical and when humans are exposed to high concentrations of this chemical it ca n result in respiratory system failure, central nervous system failure and damage to the skin, eyes and lungs. Because of the dangers associated with the application of this gas and the detrimental effects that it has on the ozone, methyl bromide is beginning to drop dead less and less used. 2. Vapam Vapam is an effective liquid fumigant for the ensure of nematodes, insects, weeds and soil borne diseases.It is not very volatile which means that it is not easily evaporated At normal temperatures and before applying this chemical it is al shipway wise to cultivate the area that is being treated in order to deliver the vapam in a uniform manner Before application the soil moisture of the field be between 50% to 80% field capacity this chemical can be applied in a number of ways some bring through sprinkler sprinkler and flood applications provide the best insurance coverage and thus the most successful this product is however toxic to seek so you should not apply this to areas whe re the surface piss can easily be washed on to lakes or streams, 3.Basamid Basamid is a granular and eliminates weeds, nematodes grasses and soil diseases. When this chemical ingredient hits the moist soil the graduals breakdown and release gases that parcel out in the soil and these gases eliminate the unwanted disease or pests. When applying basamid it is very important to keep the soil wet for 2 week, prior to the application in order to meet the right soil moisture level and every incorporated on to the soil to about 15cm using a rotary cultivator or something that has this same effect .After doing this, it is important to seal the area with a plastic of some sort of aright fumigate the soil, keeping all the volatile and highly toxic gases in that specific area. SOIL STERILIZING EQUIPMENT (LOKO kettledrum) A steam kettle bunkers or steam generator is a bend used to create steam by applying heat energy to water. The form and size depends on the application the locomotive boiler is portable mobile steam engine with same features as the large one.The only(prenominal) difference is variation in size of component part the LOKO Boiler is made up of the following part 1. FIRE TUBE BOILER This is a single furnace, three anatomy type pom-pom electron electron tube boiler. Heat-flue gases-travel is through three different sets of tubes. All the tubes are surrounded by water which absorbs the heat . As the water turns to steam, pressure builds up with in the boiler one enough pressure has built up the engine driver will open the main steam outlet valve slowly. Fire tube boilers are also known as smoke tube and domestic ass boiler. . WATER TUBE BOILERS The large tube like structure at the top of the boiler is called the steam drum. You could call it the heart of the boiler. That is where the steam collects before being discharged from the boiler. The hundreds of tube start and eventually end up at the steam drum. Water enters the boiler, pre-heated at th e top. The hot water of course circulates through the tubes down to the demoralize area where it is hot the water heats up and flows back to the steam drum where the steam collects.Not all the water gets turn to steam, so the process starts again. Water keep on circulate until all of it turns in to or be get ons steam. BOILER MAIN divisionS BOILER SHELL- The out cylindrical portion of a pressure vessel. BURNER A device for the introduction of fuel glory in to the furnace at the decreed velocities, turbulence and concentration. The burners is the principal device for the firing of oil and or gas Burners are ordinarily located in the vertical walls of the furnace.Burners along with the furnace in which they are installed, are designed to born the fuel properly. SMOKE TUBE The min/ 3rd phase are formed by thick walled smoke tubes which are welded in to the end rest homes the arrangement of the smoke tubes considers the recommendation of ascending flue fall ines in order to p revent the information of residual-or lingering gases the first phase is a combination of a furnace tube and combustion bed live suspend by stay bar and completely surrounded by water giving valuable radiant heat transference from all surfaces.The second pass is a nest of straight 50mm boiler tubes expanded in to the upper zone of the combustion chamber and running in double to the furnace tube terminating at the front plate of the reversing chamber. The third pass is a further nest of 50mm boiler tubes running from the upper zone of the reversing chamber to the rear smoke box for exhausting to atmosphere. FRONT REVERSING CHAMBERS The front reversing chamber is equipped with large doors allowing free access to the smoke tubes and belatedly maintenance and cleaning High- role tightening material guarantees the gastight closing of he doors. spill TAP A valve connection at the lowest point for the re action of all unwanted elements from the pressure parts. FEED PUMP A affection that supplies water to a boiler. FEED WATER water introduced into a boiler during operation. It includes make-up and return condensate. FURNACE An enclosed space provided for the combustions of fuel. INSULATION A material of low thermal conductivity used to reduce heat losses. asylum VALVE A spring loaded valve that automatically opens when pressure attains the value oscilloscope used to prevent excessive pressure from building up in a boiler.SAFETY SHUT- OFF VALVE A manually opened, electrically latched, electrically operated safety shut-off valve designed to automatically shut-off fuel when de-energized. WATER LEVEL The fosterage of the surface of the water in a boiler. ACCUMULATOR A pressure vessel containing water and/or steam which is used to store the heat of steam for use at a lale period at some lower pressure. FIRE stroke The excite box is surrounded by water in the out fire box shell and so absorbing radiant heat from the fire.The gap between the inner and o uter fire boxes is maintained by hundreds of rigid stays. AIR ATOMIZING OIL BURNER A burner for firing oil in which the oil is atomized by compressed air, which is force into and through one or more streams of oil which result in the breaking of the oil into a fine spray. BAFFLE-TYPE COLLECTOR A device in gas paths utilizing baffle so arranged as to mold dust particles out of the gas stream. BAG FILTER A device containing one or more cloth bags revering particles from the dust lateen gas or air which is blown through it .BAG-TYPE COLLECTOR A penetrate in which the cloth filtering medium is made in the form of cylindrical bags. BREECHING A duct that transports the products of combustion between parts of a steam generating unit or to the tummy. CIRCULATOR A pipe or tube to pass stream or water between upper boiler drums unremarkably lactated where the heat absorption is low. in any case used to apply to tubes connecting heater of plane water tube boilers with drums. STEAM GENE RATING UNIT A unit to which water fuel and air supplied and in which steam is generated. t consists of a boiler furnace and fuel burning equipment, and may include as component parts water walls, super heater, reheater, economizer, air heater, or any combination thereof. STEAM SEPARATOR A device for removing the entrained water from steam. STRAINER A device, such as a filter, to retain solid particles allowing a liquid to pass. SMOKE BOX The smoke box is an extension of the front end of the boiler barrel. rake steam from the cylinder passes through the blast pipe into the chimney and creates partial vacuum. This causes hot gases to be drown through the grate and fine pickle door.The smoke box also contains the main steam pipe to the steam chest, blower, super heater school principal, tube and exhaust for the vacuum ejector where fitted. BRICK swerve The brick arch serves several purpose. It protects the fire box tube plate from the direct flame of the fire, radiates heat to prev ent rapid fluctuation of the tube plate temperature and ensure thorough combustion of volatiles by lengthening their path from the fire to the tube plate. FIRE DOOR Fire hole door take off from locomotive to locomotive. They gives access to firing and can be adjusted to control the flow of secondary air.BAFFLE PLATE The baffle plate fall out in the fire hole is designed to direct the secondary air down towards the fired bed in order to mix soundly with the hot gases and flames. FUSIBLE PLUGS Fusible plugs are screwed into the fire box crown. They are of brass and have a lead cure. If the water level in the boiler drop and uncovers the fire box crown, the lead melt allowing steam to escape into the fire box. This warns the engine men and help to deaden the fire. some(prenominal) injectors should be put off immediately if this occurs and steps taken to remove or deaden the fire.SUPER grass The super heater consists of super heater header and super heater elements. Steam from the m ain steam pipe arrives at the saturated steam chamber of the super heater header and is cater into the super heater element. Super heated steam arrives back at the super heater chamber of the super heater header and is ply into the steam pipe to the cylinder. Super heated steam is more high-priced. capability SAVING DEVICES OF THE BOILER Economizers Transfer a portion of the heat in the stack gases to water being fed to the boiler. It is a heat money changer installed in the exhaust stack that pre-heats the boiler feed water.AIR PRE HEATER Transfer heat from hot stack gas to air that is to be mixed with fuel for combustion this device saves energy by change magnitude the temperature of the mixture of fuel and air prior to combustion, so more of the heat of combustion is available to heat water. TURBULATORS Twisted pieces of metal inserted in the tubes of fire tub boilers, causes hot gases to travel more slowly and with more turbulence, resulting in better heat transfer to the w ater. OXYGEN TRIM chequerS Measure stack gas oxygen concentration and automatically adjust the inlet air at the burner for optimum efficiency. . 1 ORCHARD EQUIPMENT Orchard equipments refer to the various machines (simple and complex) used on an orchard. Some of the machines include pruners, sprayers, weeders, dusters, etc. The selection of choice of any of these machines is dependent on the nature of work to be carried out at that material time. PRUNERS Also known as pruning trim or secateurs are a type of scissors for cutting off hard branches of trees and shrubs. They are strong enough to prune hard branches of trees and shrubs sometimes up to two centimeters thick.SPRAYERS A sprayer is a piece of equipment that has spray beak to apply herbicides and fertilizers to agricultural crops. Sprayers range in sizes from man-portable units to trailed types that are connected to a tractor or other self propelled units. There are various types of sprayers which include knap sack, foo t, garden, Hand compression, power, stirrup, self-propelled crop sprayer, trailed crop sprayer, etc. COMPONENTS OF disperse EQUIPMENT 1. TANK The armoured combat vehicle is a unit which holds chemicals, and comes in many different shapes and sizes. 2.PUMP The warmness creates pressure that forces the chemical to the nozzles. 3. CONTROL VALVE The control valve controls or maintains pressure and turn off the sprayer. 4. NOZZLE completion The nozzle tend controls application rate and ready the correct size droplets. 5. FILTER The filter is a unit behind the nozzle tip to reduce entrance or passage of dirty particles and blockage into the system. TYPES OF SPRAYING EQUIPMENTS 1. ULTRA-LOW VOLUME (ULV) SPRAYERS ULV equipment is designed to produce very small droplets, thus ensuring even coverage with low messs.The equipment is based on aerosol, airshear or rotary nozzle techniques. The ultra low volume machines use large volumes of air at low pressures to transform liquid into drop lets that are sprinkle into the atmosphere. Ultra low volume machines are used for applying pesticides, herbicides, fungicides, sterilizers and disinfectants among other chemicals. The ultra low volume machine consists of a blower, a formulation holding armoured combat vehicle and a pump. The blower creates a low pressure area and forces air through the nozzles of the machine. Air pressure can be controlled by adjusting the engine speed.The nozzles of the machines have a very specific shape, which causes a swiring motion of the air stream. The motion is achieved by means of several agitationary fins that forces the air to rotate. The formulation is delivered to the air by means of a supply tube that is situated in the substance of the nozzles. The motion of the airshears the liquid formulation into very small droplets and then disperses it into the atmosphere. Advantages 1. The chemicals dispersed in this type of machine are more concentrated than the chemicals used in other cro p-dusting equipments, which increase the killing efficiency. 2.There is lower risk of injury due to low pressure application. The only disfavour it has is that it requires long application times and higher technical skills. 2. KNAPSACK PRAYERS The backpack sprayer is a back mounted equipment used by sodbusters. The tank of a knapsack sprayer is not pressurized and made of grass, or galvanized steel. The pump may be fitted into or outside the tank and sucks the liquid from the tank and expels it through the discharge line. DUSTERS Dusters unremarkably refer to an aircraft used for dusting or spraying large farms with pesticides, though other types of dusters are also employed.Aerial spraying and dusting permits prompt coverage of large areas at the moment when application of pesticides is most effective and avoid the need for wheeled vehicles that might damage crops. COMPONENT PARTS OF A DUSTER 1. HOPPER For storing the chemicals in dust form 2. AGITATOR An agitator is used to k eep the dust moving freely within the hopper and prevent caking. 3. Metering mechanism- which is unremarkably an adaptable orifice that allows the rate of discharge to be varied. 4. Delivery blower which creates an airstream that is used to carry the powder to the target?The major difference between dusters and sprayers is that a sprayer is a machine that applies fluid chemicals to crops in liquid form while a duster is a machine that also applies fluid chemicals but in powdered form. WEEDERS Weeders refers to the various equipments used to ease the task of removing weeds from orchards or gardens. Very common weeders include the fulcrum weeders, the Cape Cod weeders, and the cracle weeder. These weeders come in two styles short handled weeders and long handled weeders.Short handled weeders are like for small gardens with small plants while long handled weeders are for bigger gardens that have bigger weeds. 3. 0. SORTING AND rate OF HORT. CROPS variety separates into groups diff erent physical properties while scoring separates into groups with different quality characteristics. Sorting and mark are usually the last separating operations before processing or displaying crops for sale. It should however be noted that damages at the stages of sorting and grading are probable to result in substantial economics loss. REASONS FOR SORTING AND GRADING OF HORT. CROPSSorting and grading of Horticultural crops controls the effectiveness of the subsequent operations because 1. Sorted and ranked products are better suited to mechanical operations such as peeling, blending , etc e. g. use of caustic soda or boiling water with vegetables which helps flavor. 2. Sorting and grading is necessary in processes which heat transfer is comminuted e. g. sterilization. 3. Sorting and grading is advantageous in processes in which uniformity of heat transfer is desirable e. g. dehydration. 4. Sorting and grading of crops gives better control weights filled with standard scale con tainer. . Sorted and graded products fare more mesmeric in consumer use, and allows the sizing of uniformly catering packs like packets of biscuits. place and quality separation of Horticultural crops depends on an overall assessment of those properties of the crops which affect its credence as a food or as a working substance for the food processor. Grading factors may be grouped under the following size and shape, maturity (e. g. freshness of eggs, ripeness in fruits, aging in meat), texture (e. g hardness, crispness in corn flakes) and flavor and aroma. GRADING MACHINERYGrading for size and quality is an essential preliminary to marketing of fruits and vegetables braggy on commercial holdings, and many types of machines are available to assist this work. Some are cheap and simple sizing or weighing machines for grading produce which has been sorted for quality before hand. Others are complex and expensive machines which incorporate devices to facilitate sorting for quality, a ccurate sizing mechanisms and bins to facilitate packing. Grading machinery may be grouped broadly into those which grade by diam and those which grade by weight. Machines which grade3 by diameter very greatly.Some size in only one or two directions, while others rotate the produce and thereby achieve a more accurate sizing. In general, machines that grade by diameter tend to have higher output, or are quite less expensive for given output then those which grade by Weight. On the other hand, a good weight grader has many advantages. It can be used for any shape, is easily adjustable and can be used for crops that are easily blemished. Grading by weight can also be more accurate than grading by diameter, though good diameter type graders are usually accurate enough for practical purposes.Good graders do little damage to apples, most of the bruising that does occur being caused when the fruit roots into the receiving bin. This is usually negligible compared with damage incurred in p icking, and getting fruit to the grader. Output of graders varies widely harmonise to the number and ability of the operators, as well as according to the machines and auxiliary equipment employed. Some graders are equipped with automatic box-tipping devices for loading. The graders in large-scale apple-packing stations are often fed by first immersing the boxes in water and then handling the fruit on to the drier by floatation.Outputs on such high-speed machines are frequently limited by the speed of packing. No one grading machine has all the advantages, so choice of a grader requires careful consideration of the most important necessarily for the conditions in which it is to be used. It is not possible to give an adequate interpretation of any individual machine but below is a shortened description of some of the grading machines 1. SIZE GRADERS This operates in two ways as follows a. Produce falls through a circular hole of fixed size.In machines of this type the sizing boa rd has a number of rows of holes of different sizes , and the crop is carried along by means of a serial publication of wooden laths operated by a crank mechanism. The effect is to move the produce, without displace or rolling it, to successively larger holes, until it falls through. b. As produce moves along conveyor, size of opening increases. Graders with mechanisms of this type are common, and include apple graders, in which the fruit is rapidly rolled along by a soft rubber belt, while leaning against a rubber bulwark set at a gradually increasing distance from the belt, and machines with diverge rubber belts. . WEIGHT GRADERS In weight graders, each fruit rests in an individual hinged cup, and for much of the journey along the conveyor the cup and fruit are supported in an upright position by a fixed guide rail. At suitable intervals, however, the support is provided by an adjustable lever-type weighing device. When the moment exerted by fruit and cup is sufficient, the cup tips, and deposits the fruit into its appropriate bin. 5. 0 MECHANICAL HARVESTING OF HORTICULTURAL FRUITS HARVESTING Is the process of gathering mature crops or fruits from the fields.Harvesting marks the end of the ontogenesis cycle for a particular crop, and the harvest is the focus of a growth season. It is the most labour intensive activity of the growing season. Mechanical harvest equipment tends to be designed mainly for fruits which are to be processed rather than those for fresh market. The main types of equipment used are combing devices and vibrators, Black currant harvester with shakers, as well as redcurrant harvesters with similar shaker units for grapes. Also available are slider cranks, tree shakers which make use of spotting and collecting devices mostly applicable for olives.IMPORTANCE OF TIME OF HARVESITN OF HORTICULTURAL CROPS 1. It reduces wastage of crop produce since most fruits tend to rot when not harvested in time. 2. It gives the farmer more quality yi eld. When fruits in particular are harvested before they are fully ripe, they tend to be sour. 3. Timely harvesting of leafy vegetables gives agency to greater yield as the cut away leaves give room for more to shoot out. COMPONENTS PARTS OF A MECHANICAL FRUIT harvester 1. An impactor for dislodging fruits from a fruit-bearing tree limb mounted on a placement arm.The arm moves up, down, forward, backward and twists. 2. A collecting conveyor for catching and conveyance of title the dislodged fruits. The conveyor is supported by a frame and is comprised of series of supporters covered by a catching surface having an energy-absorbing flexible material. 3. A transfer conveyor which is supported by a frame and is determined below the outlet of the collecting conveyor. It receives fruits from the collecting conveyor. 4. A collecting salt away which is place below the outlet of the trans conveyor in which harvested fruits are deposited.