CONSWU‘CUON, EVALUATION Am EFFICtENCY STUDIES OF A MECHANICAL CUCUMEER HARVEfiTER Thu“ 50? Ha Dog". 05 M. S. MICHIGAN STHE UNIVERSETY George William Bingley 1959 H mm m H! mm w: in w ungm 1111mm: :1 ‘ 3 1293 4 LIBRARY ‘ MiChigan Stan f Univcss‘i-ty CONSTRUCTION, EVALUATION AND EFFICIENCY STUDIES OF A MECHANICAL CUCUMBER HARVESTER BY George William Bingley AN ABSTRACT Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the reduirements for the degree of MASTER OF SCIENCE Department of Agricultural Engineering 1959 Approved My /flV’/zé ii George William Binglez Michigan growers receive over five million dollars annu- ally from pickling cucumbers. Harvesting this crop by present methods costs the growers over two and one-half million dollars. The development of an efficient mechanical cucumber harvester would reduce the costs involved in harvesting and in labor pro— curement. The first step toward mechanization of the cucumber har- vesting operation was the introduction of a human carrier-- designed to reduce the physical effort in hand harvesting. A project was set up in 1957 to develop a mechanical cucumber harvester at Michigan State University in cooperation with private industry and financed by the National Pickle Packers Association. The present investigation was conducted to evaluate the efficiency of the pneumatic vine trainer and the mechanical cucumber harvester which was designed and constructed for this research endeavor. Synthetic cucumber fruit and vines were develOped to be used in testing various harvester components during the off season. An experiment was conducted to confirm and extend the basic physical preperties of the pickling cucumber fruit and vine. The pneumatic vine trainer was 75 percent effective in positioning the vines in the desired direction for harvesting. iii There was an undesirable effect resulting from the use of the trainer--the return per acre was reduced by 10 percent as compared to the return from an untrained row. A complete harvesting unit was designed and constructed to mount underneath the tractor. Mounting in this manner provided good visibility and complete control over the oper- ation of the harvesting unit. The machine was designed to harvest cucumbers from trained rows. A tapered roll pickup with retracting fingers was de- signed and developed to position the vines onto the sep- arating bed prior to the separating process. To measure the forces exerted on the vine during the harvesting process, a transducer was developed to be used with strain gage recording equipment. During the time the! vine was on the separating bed, it was established that from seven to twelve percent of the foliage (by weight) was removed. Harvesting by machine resulted in a return of only 21 to 27 percent of the value received by hand harvesting. A study was conducted on the effect of return by supplementing machine harvesting with hand gleaning operations. By using two hand gleaning operations during the first two machine harvests, it was found that the return was increased to he percent of the value received by a grower using hand har- vesting'methods. CONSTRUCTION, EVALUATION AND EFFICIENCY STUDIES OF A MECHANICAL CUCUMBER HARVESTER By George William Bingley A THESIS Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Agricultural Engineering 1959 ACKNOWLEDGEMENTS The author wishes to express his sincere thanks and ap- preciation to all those who contributed to this investigation. In particular, the contributions of the following are recog- nized: Dr. Wesley F. Buchele, who as my major professor contin- ually provided guidance and inspiration throughout the entire investigation and preparation of this manuscript. Dr. Bill A. Stout, project leader, for his constant sup- port during the evaluation of the mechanical cucumber harvester, and for editing this manuscript. Dr. Arthur W. Farrall, Dr. Merle L. Esmay, and other mem- bers of the guidance committee for administration of the grad- uate program. Members of the National Pickle Packers Association, Chicago, Illinois, for the research grant which supported this research endeavor. H. W. Madison Company, Mason, Michigan, for donating the cucumber grader. Dr. Stanley K. Ries, Horticulture Department, and members of the Horticulture Farm, for maintaining a continuous supply of cucumber vines for the evaluation of the harvester. Mr. Wayne Beckwith, Ford Motor Company, Tractor and Imple- ment Division, formerly employed on this project, for his help- ful suggestions on planning and construction of the harvester. Mr. James Cawood, foreman of the research laboratory, for providing assistance and facilities in the construction vi of the harvester. Messrs. Thomas Burenga, James Mitchell, James Perry, Harold Quackenbush and Arlen Schluckebier, student assistants, for their help in the construction and testing phases of the project. Dr. Fred Buelow, for assistance in setting up the strain gage equipment and editing the manuscript. Dr. Clement Tatrc, Applied Mechanics Department, for the use of the Brush amplifier and recording oscillograph. Arlene, my wife, for her suggestions, support and assist- ance in preparing and typing the manuscript. INTRODUCTION - — - - REVIEW OF LITERATURE INVESTIGATION - - - Cucumber Plots- TABLE OF CONTENTS DevelOpment of a Synthetic Cucumber Vine Procedure for constructing the Fruit and synthetic Requirements for using the synthetic plants in the evaluation of a mechanical cucumber harvester - - - - - - - - - - - - Confirmation and Extension of the Basic Phys- of the Pickling Cucumber Fruit ical Properties and Vine - - - Objectives Procedure- Picking force measurements- - - - - - Force to remove the cucumber plant Results and discussion - - - - - - - - - - Picking force measurements- - - - - - Force to remove the ground- - - Pneumatic Vine Trainer- - Objectives - - - - - Procedure cucumber plants Results and discussion Mechanical Cucumber Harvester from 11 12 1h 15 15 15 15 15 16 16 21 23 23 23 25 28 viii TABLE or CONTENTS, Continued Page Objectives - - - - - - - - - - - - - - ~ - 28 Design and construction of the machine - - 28 Tapered roll pickup with retracting fingers - - - - - - - - - - - - - - - 29 Separating bed- - - - - - - - - - - - 31 Secondary flights - - - r - - - - - - 35 Cleaning fan- - - - - - - - - - - - r 35 Drive mechanism - - - - - - - - - - - 37 Safety features of the harvester- 37 Test procedure - - - - - - - - - - - r - r 39 Measurement of the power requirements of the mechanical cucumber harvester- 39 Measurement of the forces exerted on the vines by the action of the pick- up and the separating bed - - - - - - 39 Size distribution of harvested fruit on the separating bed - - - - - - - - #2 Effect of machine training and har- vesting on gross return per acre- - - uh Results and discussion - - - r - r - r r r ”5 Measurement of the power requirements of the mechanical cucumber harvester- us Measurement of the forces exerted on the vines by the action of the pick- up and the separating bed - - - ~ - - hs Size distribution of harvested fruit on the separating bed - - - - - - - - 5h Effect of machine training and bar- vesting of gross return per acre- - - 56 ix TABLE OF CONTENTS, CONCLUSIONS - - - - — - - - - SUGGESTIONS FOR FURTHER STUDY REFERENCES - - - - — - - - - APPENDIX- - - - - - - - - - - Continued Page 68 7O 71 72 LIST OF TABLES Table Page 1 Method of vine training and type of bar- vest used for plot 2 and plot 3 - - - - - - 9 7-~ 2 Variation in picking force for a given size 3 Effect of pneumatic vine training on two rows for two different training dates - ~ - 27 h Comparison between the forces exerted on the cucumber vine by two different types 5 Percentage value of harvested fruit re- moved in each compartment-~2-to 3-inch 6 Percentage value to harvested fruit re- moved in each compartment--straight 2-inch 7 Value of the crop harvested in plots 2 8 Return per acre by supplementing machine harvesting with hand labor (plot 2--rows 9 Return per acre by supplementing machine harvesting with hand labor (plot 3--rows Figure 10 ll 12 13 1h 15 16 LIST or FIGURES Map of the cucumber plots used in the evalu- ation and develOpment of the experimental cucumber harvester - - - - - - - - - - - - - Materials used in molding the synthetic cuc- umber fruit and vine - - - - - - - - - - - - Picking force vs weight relationship for three cucumber varieties - - - - - - - - - - Weight-diameter relationship for SMR-ls variety for a length/diameter ratio of 2.5 t02.8---—--------------- Weight-length relationship for SMR-ls variety for a length/diameter ratio of 2.5 t02.8------------------- Force required to remove a NSC-231 cucumber vine from Hillsdale Sandy Loam soil- - - - - Pneumatic vine trainer mounted on an Allis- Pneumatic vine trainer - - - - - - - - - - - Overall view of the mechanical cucumber har- Disassembled view of the tapered roll pickup Lower camming device on separating bed - - - Separating bed showing the position of the Retainer bar located on the lower end of the Secondary flight system used in removing fruit set near the base of the cucumber plant Fan used in removing leaves from harvested fruit. Note dividers located below the fan- Safety shielding provided for the main drive shaft and main drive - - - - - - - - - — - - Page 10 13 17 19 20 22 2% 2h 30 32 3b 3b 36 38 38 Figure 17 18 19 20 21 22 23 2h 25 26 27 28 29 3O 31 xii LIST OF FIGURES, Continued Torque meter used in determining the power reQuirements of the harvester - - - - - - - The author and Dr. Buchele observing the Operation of the torque meter under field Strain gage transducer used in measuring the forces exerted on the vine by the sep- The author observing the strain gage trans- ducer and recording equipment - - - - - - - Horsepower requirements of the harvester vs Torque requirements of the harvester vs PTO Force exerted on the vine vs weight of vine with straight two-inch flights- - - - - - - Force exerted on the vine vs weight of vine with straight three-inch flights and with the retainer bar in place - - - - - - - - - a. Percent of foliage removed from the vine by the action of the separating bed- - - - - - Actual force exerted on a cucumber vine during the harvesting process with a flight Speed of 290 feet per minute- - - - - - - - Percentage (by value) of the harvested fruit removed in each compartment by grade and total value - - - - - - - - - - - - - - Percentage of fruit harvested during each individual harvest- - - - - - - - - - - - - Distribution by grade of the fruit harvested by hand and by machine - - - - - - - - - - - Semi-net return resulting from application of a variable amount of gleaning Operations with mechanical harvesting- - - - - - - - - Roller flights installed on the separating bed during the later part of the testing season--—---------------- Page to ho “3 #3 #6 h? “9 50 52 53 55 59 6O 63 66 xiii LIST OF FIGURES, Continued Figure Page 32 Position of the vines after leaving the separating bed - - - - - - - - - - - - - - - 66 33 Condition of the cucumber vines in plot 2 after six harvesting operations- - - - - - 67 3h Main stem damage on the cucumber vine resulting from the action of the secondary flights----‘-------------c-67 35 Schematic diagram of drive mechanisms- - - ~ 7h 36 Schematic diagram of transducer and cali- INTRODUCTION The annual value of pickling cucumbers received by growers in the United States is more than 19 million dollars. Michigan, with a production of h.2 million bushels, receives about 5 mil- lion dollars for the crOp each year. This is 26.2 percent of the United States value. Michigan grew 28,200 acres in 1958- 23.? percent of the national acreage. While the acreage of cucumbers has decreased 28.3 percent in the last two years, the yield has risen from 7h bu/acre to 1&8 bu/acre. The importance of the cucumber industry to the future of- Michigan can be seen from the following economic trends: The value received by the Michigan growers during the two year period, 1956 - 1958, increased by 20 percent while the national value increased only 10 percent during the same period; The production in Michigan increased by h3 percent as compared to a 27 percent increase in the production for the United States; The Michigan yield increased 100 percent while the national average yield increased only ho percent. The development of a mechanical cucumber harvester has created considerable interest throughout the cucumber industry during the past several years. Financial support was pro» vided by members of the National Pickle Packers Association and other producers in the United States and Canada. Private companies and individuals have worked on the devel- Opment of a mechanical cucumber harvester for over ten years. The Agricultural Experiment Station project calling for the 2 design and development of a mechanical cucumber harvester was initiated in the Spring of 1957. The two factors mainly responsible for the increased inter- est in the deve10pment of a mechanical harvester are as follows: the increase in harvesting costs, and the procurement of hand labor. At the present time, the cucumber grower receives one-half of the gross value of the harvested crop. From this the grower must pay the insurance and transportation costs of the pickers and cucumbers. Thus, annual harvesting costs to Michigan growers totals over 2-1/2 million dollars. The problem of procuring laborers, usually Mexican Nation- als, arises from the expenses involved in recruiting, importing and housing of laborers. This expense totals over one million dollars each year. Bailey (1958) reported that hand harvesting of cucumbers is expected to give way soon to the advances in efficiency of the mechanical cucumber harvester. The importance of the development of a mechanical harvester can be seen, not only in eliminating the problems involved in hand picking, but also from the standpoint of increased acre- age and greater capital investments. The purpose of this thesis is (1) to invent, design, and fabricate a cucumber harvester, (2) to develOp a synthetic cucumber fruit and vine, (3) to measure the forces exerted on the vine by the picking action of the flights, ('4) to evaluate the effectiveness of the separating bed, (5) to evaluate the effectiveness of the 3 pneumatic vine trainer and (6) to confirm and extend the basic relationships concerning the physical preperties of the cucum- ber fruit and vine established by Leonard (1958). REVIEW OF LITERATURE The review of literature by Leonard (1958) revealed some of the physical characteristics of the cucumber fruit and vine which must be considered in the design and development of a mechanical cucumber harvester. A brief history of cucumber har- vesting mechanization was traced to the beginning of the invest- igation. In a book published by the National Pickle Packers Association, Banadyga (l9h9) compiled and summarized all avail- able literature related to the cucumber pickling industry. The present review of literature will complete the above reviews as well as review the recent investigations and deve10pments in the mechanical harvesting of cucumbers. The first step toward mechanization of the cucumber indus- try was the introduction of the human carrier -- designed to re- duce the physical effort involved in hand harvesting. George (1955) developed a human carrier which reduced harvesting time by 15 percent. An article that appeared in the New York Times (Sept. 7, 1955, pp 33) described a prone position carrier, de- vised by Henry Schwenck, a farmer in Bridgehampton, New York. The carrier was twenty feet wide and carried six pickers. The estimated capacity of the carrier was four to five acres per day. The first concentrated effort on the development of a mechan- ical cucumber harvester was started at Michigan State Univer- sity, East Lansing, Michigan, in 1957. In a progress report concerning the deve10pment of a mechanical cucumber harvester, Stout and Ries (1959) described the harvesters that had been tested and evaluated since the start of the project. .The overall 5 efficiency during the 1957 testing season of the Grew Belt machine was 33.5 percent. The value was calculated by comparing the value of fruit harvested by machine to that harvested by hand. Based on the number of fruit harvested, the Chisholm Ryder machine, 1958, showed an average efficiency of 38 percent for three harvests. A test conducted later showed an individual harvest efficiency of 79 Percent. Stout (1958) reported on two problems concerning the bar- vesters under develOpment. These were vine damage and the in- ability of the harvester to harvest the fruit set within six inches of the base of the plant. In studies concerning the effect of applying gibberellin to vegetable crops, Vittwer and Bukovac (1957) observed that many of the first nodes, which normally would have produced flowers, remained sterile after early foliage sprays of 10 to 100 parts per million. This result may be significant in reducing or re- stricting early fruit set near the base of the plant and thus facilitating mechanical harvesting. An experiment was conducted by Stout and Rice (1959) to evaluate the effectiveness of gibberellin in delaying early flowering. The results of one test indicated considerable suc- cess. The.first flower appeared at an average distance of seven inches from the base of the plant, however, there was considerable variation in the results obtained from all the plots. Hawkins (1951) indicated it was essential to remove the first few cucumbers set near the base of the plant. Failure to 6 do so would delay the production of new blossoms. Banadyga (l9h9) reported that the growing plant will mature not over 5 - lo fruits in a season. If the fruits are removed before they attain a considerable size, the plant may produce between 35 - 50 fruits. The importance of yields has become more pronounced with the introduction of the mechanical cucumber harvester. Miller (1957) stated that concentrated early yields are necessary to fulfill the requirements of the processor. They are also im- portant from the standpoint of insect and disease problems which prevail during the later portion of the season. Pickling cucumber salting station operators urge growers to harvest frequently, usually 2 or 3 day intervals, so that a large portion of the crop will be of the most desirable. grades. In a report on the influence of the length of interval between pickings on yield and grade, Seaton (1935) observed that: (1) Total number of fruits produced was inversely prepar- tional to the length of interval between pickings. (2) Total weight in pounds, was preportional to the inter- val between harvests. (3) Lengthening the picking interval reduced the quantity of small grades and increased the quantity of larger size fruits. (h) Returns were highest from vines picked on a four-day interval. (5) Harvesting should be twice each week to produce the most profitable combination of small and large size cucumbers with a minimum of culls. In a similar report on the effect of frequency of picking cucumbers on income, Woodworth (1956) reported that frequency 7 of picking had a pronounced effect on the per acre hours of picking labor required and the value received per acre. Pick- ing 1.4 times per week required 105 hours per acre and gave a return of 275 dollars per acre, while harvesting six times re- quired 29h hours per acre and a return valued at 375 dollars per acre. With a preharvest fixed cost of 100 dollars per acre and a labor charge of 50 cents per hour, the most profitable output was 350 dollars per acre when harvesting three times per week. This corresponded to 167 hours of labor input. Stout and Ries (1959) discussed the yields obtained from #0 - 60 - and 80-inch row widths with 6 - and 12-inch plant spacing. The highest yields were obtained from rows spaced hO-inches apart, regardless of in-the-row spacings. The yields for the 60 - and 80-inch rows were 70 to 56 percent respectively of the yields obtained from the UO-inch row. INVESTIGATION Cucumber Plots Considerable time and money were expended in traveling to the fields during the investigations conducted in 1957 and 1958. The cucumber plots were located over 20 miles from the shop facilities. To eliminate the above expenditures, an arrange- ment was made with the Horticulture Department to provide a continuous supply of cucumber vines for testing. The plots were located on the Horticulture farm, only a short distance from the Agricultural Engineering Research Laboratory. Three plots were provided for the development of the experimental harvester and the determination of forces exerted on the vine by the harvester. The first planting was on May 22, in plot 1 (refer to Figure 1). These vines were used for initial harvester adjust- ments and in determining the force necessary to separate the fruit from the vine. The plants in plot 2, were initially planted in the green- house on May 11th. They were transplanted in the field on May 29th. This plot was used for the efficiency studies of the experimental cucumber harvester. Additional studies were con- ducted on the effect of machine and hand training on yield. The yields obtained from the rows with the above treatments were compared to a hand-harvested check row. Plot 3 was treated in the same manner as plot 2. The plot was planted 1h days later than plot 2. 9 Table 1 indicates the method of vine training and the type of harvest employed in plots 2 and 3. TABLE 1. METHOD OF VINE TRAINING AND TYPE OF HARVEST USED FOR PLOT 2 AND PLOT 3 Row # Plot Method of Training Type of Harvest (1) (2) 11 2 MT ' NH 12 2 MT MB in 2 MT NE 15 2 MT ME 16 2 HT NH 17 2 HT MB 18 2 MT HR 19 2 NONE - CHECK ROW HR 23 3 MT NB 2b 3 MT MH 25 3 MT RH 26 3 NONE- CHECK 30" HH 27 3 HT RH 28 3 HT NH 29 3 MT MB 30 3 MT MB 31 3 NT MH (1) Hand training - HT Machine training - MT (2) Hand harvest - HH Machine harvest - MH 10 .3512 T PLOT 2 Rows 7-22 PLOT 3 ROWS 23- 3| Figure 1. Map of the cucumber plots used in the evaluation and development of the experimental cucumber harvester. l DeveIOpment of a Synthetic Cucumber Fruit and Vine The importance of developing a mechanical cucumber har- vester has been established from an economic standpoint.- In general the rate of progress is proportional to the length of available growing season. A short season will not allow suf- ficient time for effectively developing and evaluating the ' machine since, as in all deveIOpmental-work, continuous changes are taking place. At least three alternatives were available to the research investigators for lengthening the growing season. The first and most expensive is to follow the growing season as it pro- ceeds northward. This means that all plans must be formulated well in advance. The scheduling and planting of the various plots must be done accurately. Many problems can arise that may turn a fruitful research endeavor into a complete failure. Some of these are weather and soil conditions, variation in plant varieties, and mechanical failures. The second alternative is to provide a plastic greenhouse large enough to accomodate a harvester for testing purposes. The greenhouse would be used in starting plants earlier in the season as well as providing later plantings for testing pur- poses.. Such a system was constructed during the summer of 1959 on the Horticulture farm at Michigan State University and will be available for future testing. 12 The third alternative, and the least expensive is to develOp a synthetic cucumber fruit and vine. The synthetic plant would be used in the evaluation of machine components of a harvester. The greatest advantage of this system is that the evaluation can be conducted in the laboratory during the. off season. Once the characteristics of the vine have been related to the characteristics and properties of an actual vine, a component can be tested, reconstructed, and tested further to develOp a component that is functional to the har- vester as a whole. Procedure for constructégg the synthetic plant A plaster of paris mold was used to reproduce the syn- thetic cucumber. The synthetic fruit was made with a plastic compound by mixing a resin, a hardener, and a coloring agent in definite prOportions by weight. To prevent the plastic from adhering to the mold, a thin layer of grease was applied to the cavity wall. The curing process required six to eight hours and took place at ordinary room temperatures. A small wooden dowel (complete with knob) was inserted between the molds to provide a means of attach- ing the synthetic cucumber, hereafter referred to as 'synber,” to the vine. An overall view of the materials used in the con- struction of the synthetic plants and the completed synbers is shown in Figure 2. Figure 2. Materials used in molding the synthetic cucumber fruit and vine. 1. 2u7-e Resin.(1) 2. 358-G Hardener. 3. Plaster of paris mold. h. Mold with synthetic cucumber in place. 5. Section of synthetic vine. 6. Completed synber. 7. Attachment device. (l) The plastic compounds were purchased from Kish Industries, Lansing, Michigan. 1% Requirements for using the synthetic plants in the evaluation of a mechanical cucumber harvester. The synthetic plant must be durable and withstand the aggressive action of the harvester components throughout a series of tests. A second requirement is that the attachment must provide a variation in the force required to remove the fruit from the vine. This force will vary with different sizes of cucumbers; usually 2 - h pounds are required. The synthetic plant must be held in a position similar to the ordinary plant. It must also have a provision for attach- ing the vine to the strain gage equipment described on page #1. The synthetic plant that meets the above requirements could be used extensively in evaluating the effectiveness of dif- ferent types of pickups separating beds, and other components of an experimental cucumber harvester. The synbers could also be used in improving the quality of pickling cucumbers received in the stations. Models could be made of rejects and undesirable fruit and placed on a stand near the sorting or grading machines. Machine Operators would use the models as a guide in eliminating undesirable fruit. Synbers were molded by the author in cooperation with Libby, McNeill and Libby Company in 1959 and used in this man- ner. The synbers could also be used in establishing the effect- iveness of a grader, by grading a known quantity of synbers and checking the graded product. Confirmation and Extension of the Basic Physical Properties of the Pickling Cucumber Fruit and Vine Objectives 1. To confirm the relationships develOped by Leonard (1958). 2. Introduce new relationships and design parameters for, the develOpment of a mechanical cucumber harvester. Procedure Pickinggforce measurementg_ Three varieties of cucumbers were selected for the measure- ment of picking forces. The varieties were: SMR-15, SMR-18, and MSU 231. A spring scale attached to the stem of the fruit, was used to measure the force required to separate the fruit from the vine. By holding the cucumber firmly against the ground and pulling in a direction perpendicular to the axis of the fruit, a maximum shearing force could be obtained. The variety SMR-15 was chosen to confirm the general weight-size relation- ship of the fruit. Force to remove the cucumber plant from the ground The experimental harvester pulled plants out of the ground during the harvesting process. To obtain design parameter . data an experiment was conducted to determine the force re- quired to remove plants from the ground. The procedure in measuring this force was to attach the scale to the base of the plant and pull up in a vertical di- rection. 16 Results and discussion Picking force measurements To confirm the relationships developed in 1958, the data obtained for the three varieties was analyzed separately by using the regression method. The form of the general equation is as follows: F = aw + b Where F = Picking force in grams. W = Weight of fruit in grams. a = Slape of the regression line. b = F-intercept. The picking force-weight relationship for the three varieties is shown graphically in Figure 3. The equations are listed below. Variety MSU-23l F = 1.21w + 1h7o (1) Variety SMR-15 r = 3.09w + 1641 (2) Variety SMR-l8 F = 12.1w + 825 (3) A distinct difference exists between the relationships developed for the three varieties. Table 2 illustrates the variation in force required to separate the fruit and vine for a given weight of fruit. For the given variety of fruit (Table 2) the difference in picking force was 180 grams for MSU-231, 350 grams for sun-12, Q50 grams for SMR-lB, and 1520 grams for SMR-15. With the present harvesters the problem of removing the small fruit was greater than for larger fruit; because the small fruit did not hang down in a position for removal by the PICKING FORCE-GRAMS F— 17 2500 2000 I500— - 0 I000— I ———- - —E}— F= I.2.Iw~+ I470 - (MSU-23l 67 DAYS) ~ -e—- F=3OQW+ 164l 500——-—- (same 67 DAYS) -— ‘ ——e— F= I2.l w + 826 : (SMR°I5 70 DAYS) C) I T*I I ( I I‘d I ( I T I I ( I I I I 0 50 I00 I50 200 W- WEIGHT— -GRAMS Figure 3. Picking ferce Vs weidlt relatienships fer three cucumber varieties. 18 harvester. Of the four varieties listed in Table 2, SMR-IZ would seem best suited to mechanical harvesting. TABLE 2. VARIATION IN PICKING FORCE FOR A GIVEN SIZE CUCUMBER VARIETY WEIGHT 1150-231 SMR-l 8 sun-15 SMR-lZ (1’ gnls e gins e $1115 e gms e ng e 20 1500 17ho 1070 1060 80 1580 1950 1780 1220 150 1680 2190' 2590 1h10 The variety SMR-lS, was used in determining the weight- size relationship. The equations were determined for an acceptable range in length/diameter ratio of 2.5 - 2.8. Plotting the data on semi-10g graph paper indicated there was a straight line relationship. For diameter: (2) 3.8e1°96D V (Figure h) (h) For length: (3) w = 2.2e°’89L (Figure 5) (5) (1) Measured by Leonard (1958). (2) Compares to u.iue3’88D developed by Leonard (1958). 0.82L (3) Compares to 2.hhe develOped by Leonard (1958). W-WEIGHT— - cams 19 200 1 1 1111111 100 1111 N. ZO 11111111111111111111 IO / 1 1 1 1 |.96 D __ W= 3.88 0 L_ 111111 01 0-— l V ' 1 l D - DIAMETER-~INCHES 2 Figure b. Veight-diaanter relatienship for SIR-15 variety for a length/diameter ratie of 2s, t. 2e8e 20 200 : 11 1111 100 / 11L1 \ 2 a a z / I20- 1; : I '°_ 3 - / .1 0.89'L 5 W3 2.26 a 01 1 11 11L 0—1—1V . .1 4 .1 .1 l 2 3 4 5 L- LENGTH -- INCHES Figure 5. reign-length relasienship fer all-15 variety for a length/diameter ratio of 2.5 te 2.8. 21 Where Weight of fruit in grams. Diameter of fruit in inches. Length of fruit in inches. N D L e Base of natural logarithms. Force to remove cucumbertplants fgom the ground The general relationship between the force required to remove the plant from the ground and the weight of the plant is shown in Figure 6. The force ranged from 10 to 25 pounds for plants grown in Hillsdale Sandy Loam soil. Additional information concern- ing the forces exerted on the cucumber vine by the separating bed is summarized on page 39. Many factors, including soil and weather conditions, age of plants and variety of plants, will influence the ability of the plant to resist being pulled from the ground. 22 C 5 -1 IJL, FORCE TO REMOVE VINE FROM GROUND-POUNDS (fl --__iL._.. __ -_.-_.- _ <3 Figure 6. j I I 200 T 400 I I I 600 I I WEIGHT OF VINE-POUNDS Force required te remove a use-231 cucumber vine frem Hillsdaie Sandy Lee- seil. I 800 Pneumatic Vine Trainer The mechanical cucumber harvester developed for this in- vestigation, as well as other harvesters which pick from one side of the row, require trained vines that extend from only one side of the row. Vine training is an Operation performed on the growing vines when they are 12 to 16 inches long. The vines are moved to one side of the row by means of an air stream directed per- pendicular to the row. Objectives 1. Improve the pneumatic vine trainer developed in 1958. 2. Evaluate the performance of the pneumatic vine trainer. Procedure The pneumatic vine trainer (Figure 7) was one of the most important develOpments Of last year's work (Leonard 1958). Since the vine trainer was working well, only a few refine- ments were added to the machine to improve the efficiency and convenience Of Operation. A new shovel-mounting frame was installed on the Allis Chalmers Model G tractor. The frame included the following parts: (1) lever system for lifting, (2) gage wheel for depth control, (3) small plow-type shovel, and (h) adjustments for spacing and mounting of the shovel (Figure 8). The disc used on the 1958 trainer placed a small mound of soil on the base of the plants after the vines were trained. 211 .4 WWT’;«U’ 2"11"; Figure 7. Pneumatic vine trainer mounted on Allis Chalmers Model G tractor. Figure 8. Pneumatic vine trainer. Note air distributor, gage wheel, and shovel. 25 Because the disc damaged the root system, a plow-type shovel was installed. The performance of the pneumatic vine trainer was deter- mined by evaluating the training Operation on two rows during two training Operations. The number of vines growing on either side of the row and the number of vines growing in the row were counted both before and after training. A vine was considered to be growing in the row if it laid within a 30° angle from either side of the center of the row. Results and discussion The vines in the second plot were trained on three dif- ferent dates; June 30th, July 7th, and July let. Owing to the training effect of the picking bed, further pneumatic train- ing was unnecessary. Vines having more or less growth than those used in this test may have to be trained on a different schedule. During the first and second training Operations the tractor speed was 1-1/2 miles per hour. In the third training oper- ation, the tractor speed was 2-3/4 mph. Machine capacity at the respective forward speeds was, 1-1/3 and 2-1/2 acres per hour for an eight-foot row spacing. The air flow rate necessary in the training Operation depends upon the age of the plants, amount of foliage, and in- the-row spacing of plants. Initially an air flow rate of 3,000 cubic feet per minute was used. When the vines reached a later stage of maturity, less air was needed because most of the laterals were aligned in the direction of training. 26 When the period of time between training is too long, the vines will entangle and become a solid mat. At this stage it is impossible to train the vines. During the first and second training operations the shovel was operated at a depth of two to three inches in the soil and six to eight inches away from the row. The shovel was removed completely during the third training Operation. Dur- ing the third operation the extension of the fan was removed to enable the tractor to Operate without injuring the ends of the long vines. The effect of placing soil on the plant during the train- ing Operation was compared between two rows in the third plot. One row was trained with the placement of soil on the base of the plant and compared with a check row without soil place- ment. By observation, there was little difference between the two rows from the standpoint of effectiveness of the vine training. This is insufficient evidence however, to conclude that the soil ridge is not needed. The effect of training against the prevailing wind or occurance of a violent wind storm may cause the soil ridge to play an important role in keeping the vines trained. During the harvesting Operation the mound of soil placed on the base of the plant tended to inhibit the effectiveness of the secondary flight in removing cucumbers set near the base of the plant. On the check row, the secondary flight was effective in removing cucumbers set near the base of the plant e 27 Results Of the effectiveness of the first two training Operations in the second plot, are summarized in Table 3. The general effect of each training was to reduce the number of vines and laterals growing in the row and in the opposite dir- ection to the trained vines. TABLE 3. EFFECT OF PNEUMATIC VINE TRAINING ON TWO ROWS FOR TWO DIFFERENT TRAINING DATES Before Training After Training Row Date North South In Row North South In Row No. To 5% 9!: 7. “’ 9'. 1h June 3O 19 31 50 1.5 81. 3 17 in July 7 2.7 1h.8 82.5 .7 85.5 13.8 15 June 30 9.8 no.7 u9.5 1.3 88.5 10.2 15 July 7 2.3 21.u 76.5 .5 75 2n.5 The significant facts contained in Table 3, are listed below: 1. The effect of wind and natural growth on pneumatic vine training for row 1h can be observed by compar- ing the percentage of vines trained south on June 30th (81.3%) with the percentage of vines directed south before training on July 7th (19.8%). The dif- ference can be attributed to wind action and natural growth. 2. A similar effect can be shown for row 15, with 88.5% trained south on June 30th as compared to 21.U% dir- ected south before training on July 7th. 3. On each date the pneumatic vine trainer was 75% ef- fective in positioning the vines in the direction required for mechanical harvesting. Mechanical Cucumber Harvester The importance of develOping a harvester has been men- tioned previously. Additional consideration must be placed on the type of harvester necessary from the standpoint of economy in initial cost and adaptability to various tractors. The results obtained from the 1958 investigation indicated that a machine could be built to harvest cucumbers frem one side of the row. The harvester used a mechanism designed to pick and elevate in one Operation. Mounting was accomplished by attaching the picking bed and necessary components under- neath the tractor. This type of mounting provided good visibility as well as a convenient means for attaching the harvester to the tractor. Objectives 1. To invent, design, and construct an efficient pickup. 2. Develop a mechanism to reduce the height of the separating bed. 3. Design, construct, and evaluate the separating bed. Design and construction of the machine The machine was designed from the requirements established during the 1958 investigation. Construction of the harvester, employing the flight-type picking principle, began on January 6, 1959. The harvester was completed and field tested for the first time on June 21, 1959. The harvesting unit was mounted on a model 3&0 International Harvester Tractor. An 29 overall view of the complete machine is shown in Figure 9. Tapered rollgpickup with retracting fingers During the later part of the investigation conducted in 1958, a sponge rubber roll, five inches in diameter and four feet long with one set of retracting“ fingers, was mounted on the leading edge of the separating bed. The fingered roll assisted the vacuum pickup in lifting the vines onto the separating bed. By removing the vacuum pickup, it was found that the fingered roll alone would lift the vines. With this new principle in mind, a pickup was in- vented, designed, and constructed to lift the vines onto the separating bed. The pickup had two distinguishing characteristics. It was designed in the shape of a frustum of a cone, and the pickup fingers were retractable. The frustum of a cone was used to enable the pickup to remain close to the ground and still place the vines in the correct position on the inclined bed. The pickup cone was 36 inches long, h inches in diameter at the lower end, and 8 inches in diameter at the upper or drive end. Owing to the inclination of the separating bed, the vines must be raised a greater dis- tance at the upper end of the pickup than at the lower end. The natural differential in peripheral speed at the ends of the cone enabled the pickup fo lift the vines onto the bed in a position parallel to the row. Initially the tapered roll pickup was constructed to in- clude three sets of retracting fingers with four fingers per mwmcno w. Odonwww ‘ ’ Figure 1h. Secondary flight system used in removing fruit set near the base of the cucumber plant. 37 the separating bed (Figure 15). The air stream was directed toward the end of the belt. Drive mechanism A double "B“ section V-belt sheave was mounted on the tractor PTO. Two belts connected the drive to the main drive shaft that was mounted along the right side of the tractor. The main drive shaft was used to provide power for the sep- arating bed, cleaning fan, and the secondary flight. A com- plete schematic diagram of the drive mechanism is given in the appendix. Safety_features of the harvester To provide complete protection all exposed drives on the main drive shaft were covered with suitable shields (Figure 16). The shielding not only provided a measure of safety, but at the same time improved the overall appearance of the harvester. A spring tension belt tightner was installed on the main double V-belt drive. The device acted as a slip clutch if an obstacle became entangled in the machine. 38 .__‘ Figure 15. Fan used in removing leaves from harvested fruit. Note dividers located below the fan. Figure 16. Safety shielding provided for main drive shaft and main drive. 39 Test procedure Measurement of the_power requirements of the mechanical cucumber harvester The power requirements of the harvester were determined in the laboratory with a hydrostatic torque meter(1) .guntgd directly to the tractor PTO shaft (Figure 17). A pressure gage was used as an indicating device. The pressure reading, pounds per square inch, was converted to torque, foot-pounds, by using a conversion factor of 1.309 ft-lb/psi. To obtain a relationship of the power required to operate the three components of the harvester (separating bed, second- ary flight, and cleaning fan), data were obtained in the lab- oratory for the range of operating speeds. After the power requirements of the harvester were deter- mined in the laboratory, field experiments were conducted te determine the power censumed during the cucumber harvesting operatien (Figure 18). Measurement of forces exerted en the vines by the actien of the pickup and the separating bed In erder to establish a system for evaluating the varieus types ef picking flights, a force measuring transducer was con- structed that ceuld be used in measuring the ferces exerted en .(l) The terque meter--mode1 31, range 0-260 ft-lb--is manu- factured and distributed by the Frederick Products Cempany, P.O. Bex #827, Detreit 19, Michigan. 1&0 Figure 17. Torque meter used in determining the power requirements of the harvester. Figure 18. The author and Dr. Buchele observing the oper- ation of the torque meter under field conditions. ‘41 the vine. The transducer was a cantilever beam mounted with four SR-h (type A-5) strain gages. The beam was attached to a two-inch channel iren base plate. A one-quarter inch eye- belt was fixed to the free end of the beam. The belt provided a means for attaching and holding the vine during the measuring process (Figure 19). The strain gages were mounted on the beam to provide max- imum sensitivity and complete temperature compensation. A Brush amplifier and escillegraph were used to recerd the dynamic forces. The measuring system was calibrated with a standard set of weights. The internal calibratien circuit in the amplifier was used befere each measuring period to eliminate the process of manual calibratien. A schematic diagram showing the cantilever beam, location of the strain gages, and a cali- bratien curve is presented in the appendix. The equipment was used in the laboratory (Figure 20) to determine the amount of foliage removed from the vine by the separating bed. The vine was weighed before and after the experiment (all fruit were removed from the vine prior to weighings). The time of exposure was obtained from the oscillo- graph recording. The experiment was conducted with two-inch flights by measuring the forces parallel to the separating bed, and with three-inch flights by measuring the vertical forces with the retainer bar in place. Using the weight of plant previously recorded, a relation- ship was established between this and the maximum and average forces exerted on the vine. This relationship was determined ~ 42 for flights of two- and three-inches in height. The recording system was operated in the field to deter- mino the actual forces exerted on the vine during the har- vesting process. A small gasoline powered generator supplied the electrical power to operate the recording instruments. The transducer was placed in a trench and a wooden plank placed over the trench so that the harvester could be oper- atod in the usual manner without damaging the transducer. Size distribution of harvested fruit on the separating bed Three partitions were installed on the separating bod above the cross-conveyor, dividing the upper portion of the bed into four equal compartments. The wooden dividers were located below the fan as shown in Figure 15. Each compartment served as a collecting point for the fruit harvested in that par- ticular section of the bed. The harvested fruit was removed from the four compart- ments and graded to sise.(1) The weights of the three grades--Grade 1, Grade 2, and Grade 3--woro collected from each compartment and recorded. To determine the value of the size distribution of harvested fruit in each compartment, the weight of each size was transformed into a monetary value. (l) The size of acceptable fruit received by the H.U. Mad- ison Company in 1959 were as follows: Grade 1--ranging in size up to 1 1/16” in diameter. Grade 2--ranging in size from 1 1/16' to 1 1/2' in diameter. Grade 3--ranging in size from 1 1/2' to 2' in diameter. Figure 19. Strain gage transducer used in measuring the forces on the vine by the separating bed. Figure 20. The author observing the strain gage trans- ducer and recording equipment. an The price of cucumbers in 1959 were as follows: five cents per pound for grade 1; two cents for grade 2; and one cent for grade 3. The data from each experiment are presented in Fig- ure 2?. The above procedure was followed in evaluating the effect- iveness of the following type of flights: 1. Straight two-inch flight. 2. Two- to three-inch tapered flights. Effect of machine training and harvesting on ggoss return per acre The procedure followed throughout the experiment on yield studies was standardised. Each row was first machine har- vested and then gleaned by two separate hand operations. 1. All the fruit removed from the vine by machine but dropped on the ground was gleaned.by hand. 2. The remaining fruit in a six-inch sono extending away from the base of the plant was picked by hand. The fruit was graded and a record made of the yield from each row. The value of the harvested crop was determined in a similar manner as described above. A sample data sheet for recording the weight of harvested fruit is presented in the appendix. The hand harvested rows were harvested each time the machine rows were harvested. Each plot was harvested two times per week. Two rows in each plot were used to determine the effect of machine training on yield. #5 Results and discussion Measurements of the power requirements of the mechanical cucumber harvester Torque requirements for the bed alone and, similarly, for the bed and secondary flight remained relatively constant as the speed was increased. The horsepower requirements of the complete harvester increased exponentially with speed (Figure 21), as the power requirement of a fan is proportional to the cube of the speed. At the normal operating speed of 350 revolutions per min- ute (PTO shaft speed), the maximum horsepower required to operate the harvester was three horsepower (Figure 21). Under normal picking conditions, the torque requirement of the separating bed and secondary flight ranged between 20 and 25 ft-lb, depending upon the siso and weight of the vine. Since the operating torque was 18 ft-lb, (Figure 22) the resulting difference 2-7 ft-lb was the power consumed in the harvesting process. The average increase in horsepower for picking was 0.27 horsepower. The value is insignificant when compared to the horsepower required to Operate the harvester alone. Thus, the torque meter could not be used in obtaining a relationship for the variation in picking forces. Measurement of forces exerted on the vines b the action of the pickup and the separating bed The force exerted on the vine was related to the weight of the vine and the type of flight used on the separating bed. The maximum force on the vine was determined for the straight two-inch flight with a flight speed of 290 feet per minute HORSEPOWER E6 3.0— ____ _T _ n l 2.0 —-®——- COMPLETE HARVESTER ‘ + BED 8 SEC. FLIGHTS is BED ALONE l I'r O IOO T 200 ~i \\ PTO SPEED - RPM Figure 21. Horsepower requirements of the harvester vs PTO speed. 300 47 50 I I I _‘O—‘ COMPLETE HARVESTER ~ —&—— BED 8 SEC. FLIGHTS P —‘E}— _wBED ALONE TORQUE- FT- LBS PTO SPEED -RPM Figure 22. Torque requirements of the harvester vs PTO speed. as (Figure 23). Measurement of the force was made in a direction parallel to the direction of travel of the flights. Also shown on each graph, is the average force exerted on the vine as related to the weight of the vine. The three-inch flight, with retainer bar in place, exerted less force on a vine of a given weight than did the two-inch flight without the retainer bar (Figure 2b). A summary of the forces exerted on the vine by the two types of flights is given in Table h. TABLE h COMPARISON BETWEEN THE FORCES EXERTED ON THE CUCUMBER VINE BY TWO DIFFERENT TYPES OF FLIGHTS l 1 TYPE OF FLIGHT Height of Straight 2-inch Straight 3-inch Vine Without Retainer Bar Vith Retainer Bar Max. Ave. Max. Ave. lb lb lb 1b 1b‘fi" 1 9.2 3.3 5.8 1.5 2 18.5 6.2 9.0 2.8 (1) (1) 12.2 u.2 t. 15.3 5.6 '- (1) Measurement did not include vines weighing more than three pounds. A comparison of the force exerted on the vine (Table h) with the force required to pull a vine from the ground FORCE ON VINE - POUNDS 18 :4 d - _‘ MAXIMUM '2 ‘ FORCE ~ E] l0 4 r 8 q n/ 6 - fl, . ~ A 4 T /& AVERAGE 2 “ FORCE _5 OT W 1 I |l r I T I I T r I F O 2 WEIGHT OF |V|NE--POUNDS Figure 23. Force exerted on the vine Vs weight of vine with straight two-inch flimtSe 50 q TF—_—- [6-1 '4‘ MAXIMUM .. FORCE 8 4 2'25 -— 3 _ O O'Io 1 - l m ._ : . fa .2. a f“ > 8- f 2 — El 06—————-— {S Ell) _. LI. _: } AVERAGE 2 9 _ FORCE (3 d T I T l I I D I 2 3 4 WEIGHT OF VINE--POUNDS Figure 2“. Force exerted on the vine vs weight of vine with straight three-inch flights and wit. the retainer bar in place. 51 (Figure 6) will indicate the necessity of using the retainer bar with the fabric-flights. The percent of foliage removed from the vine increased with the time (Figure 25). The normal time interval that the cucumber vine was exposed to the separating process was from three to four seconds. During this time the two-inch flight removed from seven to eight and one-half percent of the foliage by weight while the three-inch flight removed from nine to twelve percent. Figure 26 shows the actual forces exerted on the vine during the harvesting process. The lower graph is a repro- duction of the force recorded during the first pass of the vine over the separating bed and the upper graph is the recording obtained during the second pass. The graphs are typical of the recordings obtained by using the two- to three-inch tapered flights. Each graph is divided into four sections. The first section covers the time required to pick up the vine. Section two is the time the vine passes over the stripper roll. The separating process occurs during the third section. The fourth section covers the time the vine falls from the bed to the ground. Roller flights were installed on the separating bod during the later part of the testing season (Figure 31). From the recordings of the tapered and the roller flights, a distinct difference was noted between the two types of flights. The tapered flights exerted a force over a longer period of time than the roller flights did. The roller flight, however, FOLIAGE REMOVED- PERCENT _ 52 30 --—- M’- 20 ~- y IO 6 STRAIGHT 3" FLIGHTS —— o - --111 . 30 4 4g? 0 O _—-—-—-- 20— -——~41~---—~~-~--«-—--«r / - +————-®—+ $6 0 I0+————o 1-.-“ 1 G ' STRAIGHT 2" FLIGHTS o Ill. 0 5 IO IS 20 25 TIME ON BED--seco~os Figure 25. Percent of foliage removed'frem the vine by the action of the separating bod. -___1 4 . r T“... SECOND RUN -« s 1 t-_————-—__._.. _ FORCE ON VINE——POUNDS o , . r , s . 1 . s r J 1 a m M- 1.11 \ '1 I 1 4‘ FIRST RUN :31 \\ OT I I I Ij I r I I I I O I 2 3 4 5 6 7 B 9 l0 TIME-- SECONDS Figure 26. Actual force exerted on a cucumber vine during the harvesting process with a flight speed of 290 feet per minute. 5h reached a maximum value and remained there longer than the tapered flights. Size distribution of harvested fruit on thefgeparating 355; The results of the experiment conducted to determine the effectiveness of two types of picking flights are given in Tables 5 and 6. Figure 27 presents the breakdown of the per- centage (by value) of each grade removed in each compartment for two different types of flights. The total percentage value of the crop collected in each compartment on the sep- arating bed is also presented. TABLE 5 PERCENTAGE VALUE OF HARVESTED FRUIT REMOVED IN EACH COMPARTMENT--2- TO j-INCH TAPERED FLIGHTS Compartment Total Removed Grade Grade Grade Rejects No. (By Value) 1 2 3 (By Weight) if T—T—r—‘T‘ 1 no.0 20.0 nu.5 “2.8 06.0 2 25.0 33.3 33.h 16.3 26.h 3 21.0 13.h 5.b 3h.8 21.6 I» 1.2.9. 221212.242. 6.0 Totals 100.0 ' 100.0 100.0 100.0 100.0 The tapered flights removed a greater percentage value of the fruit in the first compartment than did the PERCENTAGE FRUIT REMOVED IN EACH COMPARTMENT _55 'O'T-z- 3" TAPERED \ - FLIGHTS \11/ \j1 o 1 GRADE I GRADE 2 GRADE 3 ——1~ TOTAL VALUE IOJv STRAIGHT 2" FLIGHTS 0 1 1 l_ 3 4 I 2 COMPARTMENT NO. Figure 27. Percentage (by value) of the harvested fruit removed in each compartment by grade and total value. 56 straight flights. A larger amount of grade 2 was also col- lected. In each case the larger size fruit was removed first. The straight flights would seem best in that a decreasing trend is obtained in the percent of fruit harvested from compartment one to compartment four. The best type of flight would give a curve indicating a high percentage return in the first compartment and a lower percentage re- turn in the fourth compartment. TABLE 6 PERCENTAGE VALUE OF HARVESTED FRUIT REMOVED IN EACH COMPARTMENT--STRAIGHT 2-INCH FLIGHTS Compartment Total Removed Grade Grade Grade Rejects No. (By Value) 1 2 3 (By Height) 1'“ i as as T‘- 1 31.2 2h.0 23.5 “3.2 “7.5 2 29.7 2h.o 37.h 22.0 23.0 3 20.6 20.0 22.6 18.0 20.5 n 1912 2.819. 12.11612 .22 Totals 100.0 100.0 100.0 100.0 100.0 Effect of machine training and harvesting on ggoss return_per acre The vines in plot 2 were harvested nine times. The num- ber of harvests in plot 3 was reduced to seven because of disease problems. Table 7 gives a summary of the return per acre for both plots. 57 TABLE 7 VALUE OF THE CROP HARVESTED IN PLOTS 2 AND 3 Row Type Of Type of Return Return For Acre Training Harvest Per Acre Equal.£lamt Population Basis L 3 lb Machine Machine 39 - 16 Hand Machine 38 - 18 Machine Hand 186 168 19 Check Row Hand 187 187 2“ Machine Machine #7 - 25 Machine Band 175 163 26 Check Row Band 191 191 27 Hand Band 180 172 28 Hand Machine 51 - 29 Machine Machine #3 - 30 Machine Machine 51 - The effect of machine training and harvesting on yield as shown in Table 7 is very significant. The economic efficiency of the harvester was 21 percent in plot 2 and 27 percent in plot 3. The effect of the machine harvesting process was to reduce the average yield by 76 percent. The economic efficiency values were not obtained from a statis- tical analysis. They should only be regarded as trends resulting from the machine harvesting process. 58 One factor that tended to lower the economic efficiency was the initial injury to the vines. The injury does not show up immediately but will affect the final return per acre. Table 7 also indicates there is an effect on the return per acre owing to the use of the pneumatic vine trainer. In both plots for an equal plant pepulation basis, a reduction in return of over 10 percent was experienced. The decrease in returns may be a result of moving the vines in one direc- tion and removal of some of the female flowers during the training process. Individual harvest efficiencies increased during the season. The average increase for two rows in plot 2 and plot 3 is shown in Figure 28. As the plant matures, fruit is set farther out on the vine resulting in an increase in machine efficiencies. A decrease was also noted in the fruit remaining in the six-inch zone near the base of the plant and the fruit left on the ground. Figure 29 shows the distribution of the three grades of fruit harvested by hand and machine methods. Harvesting by hand gave a larger percentage of grade 1 fruit than did machine harvesting. Since some fruit was left on the vine after each machine harvesting operation, the fruit harvested during the next operation would be larger in size. The economic efficiency of the harvester described in this thesis averaged 2h percent. In an effort to improve the return received by the grower, a time and cost study was conducted using hand labor as a supplement to the harvesting FRUIT HARVESTED-PERGENT 59 am; £HT‘T“? SOL—I ° a ‘ W —-0— MACHINE HARVEST -—+ ‘8— REMAINING ON VINE ->- '1 O a -GI— LEFT 0N GROUND q I I 20‘ A -i. ———— -‘ J Y . - A, ' A A A ‘u’i\a’e I I I l l 0 I I I I I 2 3 4 5 6 7 8 9 80-“ PLOT 2 -- ‘1' 20' 1 1L . I A]: 0 I I I I I ‘I I 2 3 4 5 6 7 HARVEST NUMBER Figure 28. Percentage of fruit harvested during each individual harvest. SIZE DISTRIBUTION OF HARVESTED FRUIT-PERCENT 8‘3 60 I / 20: IO“ M '1.» . .2? F GRADE 3 I O I I POI CD CD I 8 I NI DO (3 l 0? tn C) L I - DO 9) (D ._ —0—r MAGHFHARV. _ (IRAQI: ' ‘V‘1HAND HARv. I I I I I I CD I 2 3 4 5 G 7 8 9 HARVEST NUMBER Figure 29. Distribution by grade of the fruit har- vested by hand and by machine. 61 process. Hand labor was used to pick the fruit knocked on the ground and the fruit remaining near the base of the plant. The labor requirement for the machine operator was 1 3/h hours per acre. The gleaning Operation required 3 hours per acre. The cost of labor was estimated to be $1.25 per hour. Tables 8 and 9 summarizes the return by using hand labor to glean the row after machine harvesting(Figure 30). TABLE 8 RETURN PER ACRE BY SUPPLEMENTING-MACHINE HARVESTING VITH HAND LABOR (PLOT 2--ROWS 16 AND 18) Gleaning Gross Return Labor Semi-Net (1) Operations Per Acre Cost Return Per Acre $ IS $ 0 38.25 19.75 18.50 1 “8.00 23.50 2h.50 2 5h.25 27.25 27.00 3 56.00 31.00 25.00 b 58.25 3h.75 23.50 5 59.50 38.50 21.00 6 60.25 “2.25 18.00 7 61.00 46.00 15.00 8 61.50 09.75 11.75 9 65.25 53.50 11.75 (1) Does not include expenses for repairs, fuel, and depreciation of harvester. 62 he gross return by machine harvesting alone was $38.25 per acre (Table 8). When the first machine harvest was sup- plemented with a gleaning operation the gross return increased to $h8.00 per acre; which corresponded to a semi-net return of $2h.50 per acre. The highest semi-net return--$27.00 per acre-~was received when the first two machine harvests were supplemented with gleaning Operations. Similarly, in plot 3 (Table 9) the highest semi-net return--$h0.00 per acre-dwas realized when two gleaning operations were used. TABLE 9 RETURN PER ACRE BY SUPPLEMENTING'MACHINE HARVESTING-WITH HAND LABOR (PLOT 3--ROWS 28 AND 29) Gleaning Gross Return Labor Semi-Net (1) Operations Per Acre Cost Return Per Acre 3 $ $ 0 51.00 15.00 36.00 1 58.00 18.75 39.25 2 62.50 27.50 “0.00 3 65.50 26.25 39.25 2 67.50 30.00 37.50 5 70.25 33.75 36.50 6 71.00 37.50 33.50 7 72.50 “1.25 31.25 (1) Does not include expenses for repairs, fuel, and depreciation of harvester. 63 g. N ‘I‘ l I l 20‘ 1 :1 I5 PLOT 2 11 1 ROWSI68I|8 1 I0~ OL r 1 0 I 2 S 4 5 G 7 8 9 SEMI- NET RETURN “DOLLARS/ACRE q PLOTS- .7 3O ROW828830 1 02 1 1 1 I I I I I 0 I 2 3 4 5 6 7 HAND GLEANING OPERATIONS Figure 30. Semi-not return resulting from application of a variable amount of gleaning operations with machine harvesting. 6h The results in Table 7 show a return for hand harvesting in plots 2 and 3 of 187 dollars and 191 dollars respectively. Since a grower would receive less than half of the amounts presented--95 dollars-~the semi-net return per acre from each plot would be 28.h and #2 percent of the net return received by the grower. The gleaning operation can be performed with case, since the vines are trained in one direction and the base of the plant is exposed to the gleaning Operation. Machine_performanco The mechanical cucumber harvester develOped for this research endeavor provided an effective means for obtaining data on machine efficiencies and the reduction in yield and income as a result of mechanical harvesting. The capacity of the harvester ranged from 0.8 to 1.2 acres per hour based on a row width of eight feet. The row width is expected to decrease to a minimum of five feet for a machine designed to harvest trained rows. The tapered pickup worked very well in every respect. Although three sets of retracting fingers were initially in- stalled on the pickup, another set could have been added to assist in lifting the longer vines onto the separating bed. The separating bed, using the fabric material for flights, worked effectively in elevating the harvested fruit to the conveyor. It did not function effectively in removing the fruit from the vine. The fabric flight would bend back as the flight moved underneath the vine. To improve the picking 65 process a set of roller flights were installed (Figure 31). The roller flights exerted a greater force on the vines resulting in excessive foliage removed. While the secondary flight provided assistance in re- moving the fruit set near the base of the plant, it also caused some damage to the main stem of the plant (Figure 3“). Dirt and trash were often thrown onto the separating bed by the secondary flight system. The vines drOpped off the separating bed in a favorable position for the next harvest (Figure 32). As the season progressed and the vines grew to greater lengths, considerable dragging occured as the vine tips caught on the bed-mounting frame. Figure 33 is a general view of plot 2 showing the con- dition of the vines after six harvesting Operations. The weather was favorable throughout the growing season and pro- vided excellent growing conditions. Another factor which contributed to the rapid growing of healthy vines was the installation and Operation of an irrigation system at the beginning of the growing period. 66 . ;. , 5V . 1" ‘ ’ . P y s. 3% “‘1. $4.5: /. he" ‘1» 81‘4“! ' Figure 31. Roller flights installed on the separating bed during the later part of the testing season. Figure 32. Position of vines after leaving the separating bed 0 Figure 33. Condition of the cucumber vines in plot 2 after six harvesting operatiens. ;\ 6::- P"§{"-' ~~‘ Figure 34. Main stem damage on the cucumber vine resulting from the action of the secondary flights. CONCLUSIONS The following conclusions are based on the observed per- formance of the mechanical cucumber harvester designed and constructed for this research endeavor and on the data Obtained during this investigation. 1. 8. 9. 10. 11. The force required to pull a cucumber plant from the ground was related to the weight of the plant, the variety, type of soil, and to moisture con- ditiOflS o The pneumatic vine trainer placed 75 percent of the vines in the desired direction during the vine training operation. The pneumatic vine trainer reduced the yield of the cucumber crOp by 10 percent. A positive tapered roll pickup with retracting fingers was designed, constructed and develOped. A means was develOped to accurately measure the force exerted on the vine during the harvesting process. A retainer bar was required on the separating bed to eliminate pulling the vines out of the ground. The return per acre was reduced by 76 percent owing to the combined effects of the pneumatic vine trainer and the mechanical cucumber harvester. The fabric picking flights removed from 7 to 12 percent of the foliage (by weight) during each picking. The roller flights exerted a greater force on the vines with the retainer bar than did the fabric f1 lghts o The lower camming device reduced the depth of the separating bed and assisted in removing the fruit set near the base of the plant. The vines drOpped off the bed in a position favor- able for the next picking Operation. 12. 13. 1h. 15. 69 One plot of cucumbers was harvested nine times by the mechanical harvester. Machine harvest capacities ranged from 0.8 to 1.21 acres per hour based on a row width of eight feet. The capacity of vine trainer ranged from 1 1/2 to 2 1/2 acres per hour. The semi-not return reached a maximum value when hand gleaning was supplemented with the first two machine harvests. 1. 3. 6. 7. SUGGESTIONS FOR FURTHER STUDY Study the effect of frequency of machine harvesting of cucumbers on yield and income. Statistical analysis of yield from hand harvesting of cucumbers compared to machine harvesting. Determine the effect of applying a flame to the base of the plant as a means of delaying early fruit set. Use the synthetic plant in evaluating the effectiveness of harvesting mechanisms prior to the growing season. Employ cultivation and pesticide techniques during the harvesting process. Study the effect of compacting the soil near the base of the plant on yield and income. Deve10p cultural practices that increase the efficiency of mechanical harvesting. REFERENCES Anonymous, (1955). Farmer picks pecks of prospective pickles by laying down on the job. New York Times, September 7. p 33. Banadyga, A. A. (19h9). Cucumbers for Pickles. National Pickle Packers Association, Oak Park, Illinois. 276 pp. Dailey Jr., W. E. (1958). Mechanization, product improvement are keys to increased pickle sales. Western Canner and Packer. 50(6)8131-132. May 25, 1958. George, L. F. (1955). The Maryland field conveyor. Market Grower's Journal. 8h(7):6-8. Hawkins, A. D. (1951). Maine cucumber growers solve their harvesting problems. Market Grower's Journal. 80(6) 316-17e Leonard, R. K. (1958). Mechanical cucumber harvesting. Thesis for degree of M.S., Mich. State Univ., East Lansing. (Unpublished). Miller, c. M. (1957). Studies of the nutrition and physiOIOgy of pickling cucumbers. Thesis for degree of Ph. 0., Mich. State Univ., East Lansing. (Unpublished). Ries, S. K. (1957). The effect of spacing and supplemental fertilizer applications on the yield of pickling cucumbers. Mich. Agr. Exp. Sta. Quar. Bul. U0(2)8375-381. Seaton, H. L. (1935). The influence of the length of interval between pickings on the yields and grade of picking cucumbers. Mich. Agr. Exp. Sta. Spec. Bul. 259. 22 pp. Stout, B. A. (1958). Deve10pment of a mechanical cucumber harvester. (Unpublished Report). Agr. Eng. Dept. Lib., Mich. State Univ. March, 1958. Stout, B. A. and S. K. Ries (1959). A progress report on the develOpment of a mechanical cucumber harvester. Mich. Agr. Exp. Stae Quar. BUle “1(3)3699-718e Wittwer, s. H. and M. J. Bukovac (1957). Gibberellin and higher plants: X Field observations with certain vegetable crops. Mich. Agr. EXp. Sta. Quar. Bul. h0(2):352-36h. Woodworth, H. C. (1956). Effect of frequency of picking cucumbers on income. N. H. Agr. Exp. Sta. Bul. h06. APPENDIX General Specifications of the Harvester Schematic Diagram of Drive Mechanisms - Description of Drive Mechanisms - - - - Harvesting Record Data Sheet #2 - - - - Schematic Diagram of Transducer, and 73 7h 75 76 77 73 General Specifications of the Harvester Overall length - - - - - - - - - - - - 126 inches Overall width - - - - - - - - - - - - 92 inches Row width - - - - - - - - - - - - - - 8 feet Separating bed length - - - - - - - - 60 inches Separating bed width - - - - - - - - - #2 inches Upper bed depth- - - - - - - - - - - - 11 inches Upper bed clearance- - - - - - - - - - 6 inches Lower bed depth- - - - - - - - - - - - 6 inches Flight spacing - - - - - - - - - - - - 1h inches Flight speed Fabric flights- - - - - - - - - - 29o ft/min Roller flights- - - - - - - - - - 230 ft/min 7h $ v ‘ ‘— -- \\; 1 Figure 35. Schematic diagram of drive mechanisms. Number 10 11 12 13 1h 15 16 75 Description of Drive Mechanisms Description Main drive. Double V-belt ”B” section sheaves 6-inch diameter drive to 5 l/2-inch diameter drives. Main drive shaft. Separating bed drive. No. 50 roller chain. Drive sprocket (16 teeth), driven sprocket (16 teeth). Universal drive. Gear box drive, V-belt “A” section sheaves. B-inch diameter drive to 2 l/Z-inch diameter driven. Gear box-~l:2. Fan drive. V-belt “A“ section sheaves. 6 l/2-inch diameter drive to 3 SIR-inch diameter driven. Cleaning fan. Bevel gear drive (2:1 reduction) for cross-conveyor, pickup, and stripper roll. Cross-conveyor drive. No. ho roller chain. Drive sprocket (16 teeth), driven sprocket (20 teeth). Cross-conveyor drive roll. Pickup drive. No. ho roller chain. Drive sprocket (10 teeth), driven sprocket (20 teeth). Stripper roll drive. V-belt “A" section sheaves. 8-inch diameter drive to 2-inch diameter driven. Flexible shaft drive. Secondary flight drive. No. no roller chain. Drive sprocket (12 teeth), driven sprocket (20 teeth). Secondary flight. 76 HARVESTINGIRECORD -- DATA SHEET;#2 Cucumber Harvester Project 6.3. 126 RECORDER PLANT POP BEME DATE PLANT POP AFTER PLOT NUMBER SPEED ROW NUMBER CAPACITY TYPE OF HARVEST AGE OF PLANTS REMARKS: M MACHINE HARVEST ( #1 #2 #3 ‘ Rejects Broke: l Weights : Total 5 4_ Percentages 3 LEFT ON VINE #1 #2 #6 Rejects Broken Weights Total . i Percentages I 1 1 REMAINING 0N (BROOM) #1 #2 #s Rejects Broken Weights Total Percentages 77 l —- DIA. HOLE 4 Izh— % a :1 Ra .. 1 ; L___:j Rl _%_J__ R / 3 ” ”—_4T€“‘—‘ BRIDGE CNRCUH' R e R TOP é Flt—J ' 3 | J4 / ”—R A R26 R4 BOTTOM V1 1',— 25 4 a, 1 A- 50 A-IOO A-2oo “J 20 d g . / “'J 3 j / i l5 ' -— 9 ‘1 / / a— I d 3 // / A= ATTENUATCR a / __J '5‘ 5 . SETTING i O T T T T I T I T I I T U 1' 1 T I O 5 IO IS 20 FORCE--POUNDS To obtain the above calibration, the internal cir— cuit was adjusted to give 10 lines of pen deflec- tion when the calibration button was depressed with an attenuator setting of 20. Figure 36. Schematic diagram of transducer, and calibra- tion curve. so :9. —, 35.31 [is in I ;\,.'~..,L-,_ri'-i . 1,. __ ififlku Q if)“ g ‘ I‘ . "‘3 bk IICHIGAN STATE UNIV. LIBRARIES mVIIIIIINIHIIINIWHI"HIMWWII“lHlllllHHl‘| \l 31293101400632