OBSERVATIONAL STUDIES ON THE. MECHANIZATION OF THE SUGAR BEET CROP ‘I’I'IESIS FOR THE. DEGREE OF M. S. MECHIGAN STATE UNIVERSITY ALLAN W. STOBBS 1955 THESIS - WM “mm W I 1293 O_1058440 0- “1" This is to certify that the 72'3““ ‘ thesis enlitled Observational Studies on the I-leehanization of the Sugar-Beet Crop presented by Allan I-Iili‘red Stobbs has been accepted towards fulfillment of the requirements for 1': OS 0 degree in Farm CI‘gpS {ff/@925: Major professor pm July 5, 1955 0-169 PLACE IN RETURN BOX to ram ave this checkout from your record. TO AVOID FINES return on or before date due. DATE DUE DATE DUE DATE DUE MSU Is An Affirmative Action/Equal Opportunity Inuitution Warns-9.1 OBSERVATICNAL STUDIES ON THE MECHANIZATION OF THE SUGAR BEET CROP by Allan w. Stobbs An Abstract Submitted to the School of Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Farm CrOps Approved... ‘00....OOOOOOOOOOOOOOOOOOOOO THES‘S Fur Allan W. Stobbs 2 Sugar beet production is characterized by seasonal peaks of labor requirements. Rapid progress has been made since 19h5 in removing those peaks by the development of mechanical devices to treat the seed, and plant, thin, and harvest the crop. These aspects are dealt with in the following order: Part I Sugar-beet seed, processed at the Farmers and Manufactur- ers seed plant at Saginaw, was graded according to size from less than 7/6h inch in diameter to 13/6h inch. The percentages by weight of each grade in natural, processed, and intermedi- ate seed was determined. Selected grades of seed were germi- nated in the greenhouse in order to determine the numbers of single, double, triple, etc., sprouts each gradetvas capable of producing. It was.found that: (1) processing did not seriously im- pair germination, (2) 72 percent of the viable units were re- covered in the processing operation, and, (3) Processing in- creased the number of singles by 30 percent. 2.92.1.1. Field observations were made on.the operations of Pals- grove and International planters and the "Dixie" type thinner in Huron and Tuscola counties. Results indicated the value of precision planting and mechanical thinning under ideal field conditions. The disadvantages of these machines showed up in Allan W. Stobbs a striking manner under conditions that were less than perfect. Part III Observations were made on four types of mechanical har- vesters at work during the 1954 harvest period. A description is given of each machine together with information on the weights of tare and dirt which each machine lifted. An analy- sis of these results showed little variation between the four types but did show up other factors affecting the cleanliness of harvested beets. It was concluded that although hand labor made a cleaner job of harvesting it was doubtful whether the value of clean beets would offset the extra cost in money, time and patience involved in using hand labor. All three studies showed the close tie-up and inter- relation between one phase of beet growing and another, and how, for example, a new development in planting technique influences the subsequent operations of thinning and harvesting. OBSERVATIONAL STUDIES ON THE MECHANIZATION OF THE SUGAR BEET CROP by Allan W. Stobbs B.Sc.(Dune1m) A Thesis Submitted to the School of Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of. MASTER OF SCIENCE Department of Farm Crops 1955 ACKNOWLEDGEMENTS The author wishes to express his very sincere thanks to his major professor, Dr. S. T. Dexter, for his guidance, in- Spiration and friendship, during the course of’this study. Also to Maurice G. Frakes, of the Michigan Sugar Com? pany, and his field staff, without whose co-operaticn and as- sistance these observations could not have been made. Thanks are also due to the Farmers and Manufacturers Beet Sugar Association for permission to collect data from their seed processing plant at Saginaw; Sincere appreciation is also expressed to the W. K. Kellogg Foundation by whose generosity the whole experience of living and working at an American university was made possible. Finally, the author wishes to place on record his grati- tude to all the nembers of the staff of the Farm Creps Depart- ment who, through their friendship and help, have made his sojourn in the United States such a pleasant one. 35810i CONTENTS INTRCI)UCTI()NOOOOIOOOOOOOOOOOOOOOCOOCOCOOOOOOOOOOOOOOO PART I - PROCESSED SUGAR BERT SEED................... Review of Literature........................ Seed Processing............................. Germination................................. COflClUSionSeeeeeeeeeeeeeeeeoeeeooeoeoeoooeoe PART II - PLANTING AND THINNING ..................... Review of Literature........................ Field Observations.......................... Discussion.................................. COflClUSionSeeeeeeeeeeeeoooooeeoeoeeoeaoeoeee PART III "' HARVESTING EQUIPIVIENTooeeeoeeeeoooeeeeceooo Types Of HarVeStereeeeeoeeeeeeeeeeeeoeeeeeee Performance of Harvesters in 195h........... conCIUSionSOOOOOOOOOOOOOIOOOOOOO0.00.0.00... GE’IERAL SUPIWLARYOOOOOOOO.OOOOOOOOOOOOOOOOOOOOOOO00.... LITERATURE CITEDOOOOOOOOOOOOOOOOO00.00.00.000...00... IA 20 23 2h 31 #0 h} #5 A6 52 60 62 65 INTRODUCTION In presenting this report on "Observational Studies on the Mechanization of the Sugar Beet Crop," it is thought neces- sary to offer some explanation for the choice of subject. Beta vulgaris (sugar beet) has been grown for the ex- traction of sucrose since Napoleonic times. During the period of the last one hundred and fifty years, the cultivation of this crop has spread throughout Europe and North America. Sugar beet production in the United States presents many interesting features, not the least of which is the very high degree of mechanization associated.with the crep. There is no doubt that this develOpment of methods by which hand labor requirements can be reduced has been fbrced. upon the American sugar beet grower by the shortage, and consequent highprice, of hand labor. _ In the United Kingdom, on the other hand, the supply of labor has been relatively cheap and plentiful so daat there has not been the same incentive towards mechanization in that country as there has been in the United States. For example, it was estimated that 63 percent of the United States sugar beet crOp was lifted by mechanical harvesters in 1951; in the United Kingdom only 20 percent of the crop was harvested by machine in that year. During recent years, the price of labor in the United -1- Kingdom has been increasing at a rate out of proportion to the value of the crop so that the need for greater mechaniza- tion is becoming increasingly apparent. Consequently, a study of recent developments in the growing of the sugar beet in the United States would be of considerable value to growers of the crop in the United Kingdom. With this object in mind and through facilities made available by the W. K. Kellogg Foundation, it was possible to make a series of observations on sugar beet production in Michigan. The following is a report on the findings of these observational studies. PART I PROCESSED SUGAR BEET SEED The so-called "seed" of the sugar beet is most peculiar when compared Wifll those of other farm creps being neither uniform in size nor germination. In its natural fornu the "seed" of commerce is really a seed-ball or fruit composed of a number of germs each enclosed in a woody outer covering or husk. For the purpose of this thesis, the word seed will be used to describe all viable units, regardless‘of whether they produce one, two, three, or more sprouts. On genmination, each seed-ball may produce from one to seven beet seedlings, depending upon the number of viable germs in the fruit, and consequently such seed causes a great deal of work when the resultant crop is thinned, work that is in- tricate, costly, and laborious. The processing of sugar beet seed was introduced to ob- tain a larger proportion of single-germ units by which it was hoped to reduce labor requirements for thinning. The relative value of sugar beet seed to a grower will depend (generic factors apart) on whether he requires: a) High germination, irrespective of‘the number of sprouts per seed-ball. -3- J“. '1 --—-— _ .‘" r t A .0. r. ... SSA ”J a. ll.- rfa‘ll b) An even distribution of singles and doubles. c) The maximum number of singles, irrespective of germi- nation. The purpose of this study, then, is twofold: 1. To make a comparison between natural and processed seed with regard to germination capacity and density of stand. 2. To examine the present processing Operation with a view to making possible improvements. REVIEW OF LITERATURE In an effort to further the movement towards mechaniza- tion, work was carried out in l9LO and 19h1 at the California Agricultural Experiment Station by Bainer (1) on the processing of sugar beet seed by passing it through a machine which "cracked" or "segmented" the seed-ball. The effect was to break the fruits up into pieces containing fewer germs, with subsequent variations in germination capacity. With the ex- ception of h.h percent of the sample that failed to go through the ll/6A inch sieve, the germination was reduced and the number of seedlings per seed-ball was halved from 2.21 in the original to 1.18 and 1.05 in the "cracked" seed. Table I. TABLE I Results of cleaning, grading,and¥germination of a sample of EgracEed" Beet seed. - after Bainer (17* Grade - Sieve % Retained fiGerminati on Seedlings/Ball Over ll/6h inch L.h 9A.O 1.76 ll/6h inch - 8/6h inch A2.2 82.1 1.18 TABLE I (Continued) Grade - Sieve % Retained % Germination Seedlings/Ball 8/6t inch - 6/64 inch 10.8 53.8 1.05 Free Germs 2.9 71.0 1.00 Dust & Screenings 39.7 Original Sample 100.0 84.5 2.21 _ A“_‘ fi‘fi v It is interesting to note that the large seed, over ll/6A inch in size, had a higher germination than.the original which was in contrast to the findings of Lynes at Wyoming (2). He feund that the germination of natural seed (widnout being treated) rose from 56 percent in the original sample to 82 percent for the fraction between 9/6h and ll/6h inch in size. Unfortunately, Lynes does not give any information on the num- ber of seedlings per seed-ball given by his re-graded seed. Price and Carsner (3) found that under critical green- house examination large seed-balls (those remaining on the h m.m. or 10/6h inch sieve) gave more rapid germination and produced more vigorous seedlings than small seed-balls (those remaining on the 2.5 m.m. or 6.3/6h inch sieve). They de- duced from this that gains in yields of beets and sugar ac- cruing from the use of larger seed would far more than offset losses involved in discarding the smallest and weakest seed - 2.5 m.m. or 6.3/6h inch. They concluded that when seed is to be segmented it would seem obviously advantageous to size the seed first, discard the small fractions, and segment only the larger sizes. Segmented seed was widely introduced in 19h2 with the aim of procuring as many single plants as possible in the sugar beet crOp. In order'to obtain a seed with a.high pera centage of single germ pieces, it was necessary to give the natural seed harsh treatment in the segmenting process and consequently germination was far from satisfactory. More recently Frakes (h) and Ryser and Owen (5) have shown that yields are not appreciably affected by leaving up to 30 percent of doubles. Consequently, the aim in seed pro- cessing has been shifted from producing seed.with a high per- centage of singles and low germination to seed as uniform in shape and size as possible containing up to 50 percent of doubles and a high germination (6). SEED PROCESSING 1) Description of the operation. The processing of natural sugar beet seed was carried out at the seed-processing plant of the Farmers and Manu- facturers Beet Sugar Association at Saginaw. The machinery used consisted of three sets of burrs and pressure plates and two Clipper mills set out as shown in the diagram. Power was provided by two 7% H.P. electric motors. Natural seed (variety U.S. #00) was fed by bucket-type elevator from a hopper in the floor to the top of the first <31ipper mill. Two screens separated the seed into three fractions: over 13/6h inch, 7/6h inch - 13/6h inch, and less than 7/64 inch. The large sized seed (over 13/6h inch) passed down into the first burr and pressure plate before falling, at B, into an auger-type conveyor running the length of the floor. Seed between 7/6h inch and 13/6h inch in size passed into the second burr and pressure plate and then fed into the auger conveyor at D. Material less than 7/6h'inch in size fell through the lower screen and was discarded as waste. The second clipper mill was fed from the auger conveyor by a bucket-type elevator, with material that had passed through the first and second burrs and pressure plates. This second mill also had two screens, the tOp one wifli a mesh of 9é/6h inch and the lower one with a mesh of 7/6h inch. Seed which passed through the first screen but remained on the second was led off into the processed seed hopper. Seed over 9fi/6h inch in size passed down through the third burr and pressure plate into the auger conveyor and was returned to the tOp of the mill together with seed from the first and second burrs and pressure plates. Seed smaller than 7/6h inch in size dropped down through the lower screen and was discarded as waste. Samples of seed were collected from the following lo- cations: ‘ \Jif .w .‘r2 L.” I. MED)»; at T( ).\ )L 1L . 2x #3! ate...) it. a a. mgr I . \ r \ - -/.W;Uw) .B. K \. Ramada . 7.1.... . 4.12 4.22 Edalaqo tmaa....o .KOFQ>U..M 9100mm. F our... . .wauzm a N that. 4.1.5035 H2.i.t..4 .m- 6 ammudomm. QMMm: [www.m. mien m, was No. FDCTIJ are uO Engage Location of‘Samplg Designation of Sample A Over 13 - After burr B Over 13 - After pressure plate C 13-7 - Before treatmant D 13-7 - After burr E 13-7 - After pressure plate F Over 9% - Before treatment G Over 9% - After pressure plate H Processed Seed (finished) 2) masseuse-miss Each sample of seed was sized over round-holed hand sieves, graded in 6hths of an inch, and fractions of each size in a sample were weighed. Counts were made to ascer- tain the number of seed-balls per pound. The results.are given in Table II. 3) Discussion of the Results In considering the effectiveness of the various stages in the processing of seed, it was obvious that the burrs did not do very much work. Table II shows that 2h percent of fine original natural seed was graded off, larger flian 13/6h inch, on the first clipper mill and passed into the first burr. 0f the remaining 76 percent, 1.5 percent fell through the lower sieve as trash and the rest, from 7/6h to 13/6h inch, passed into the second burr. Table III shows the effect of burring on the material passing into the second burr. -10- TABLE 11 Resultggqf GradingASamples of Sugar_Beet Seed Size (6hths") 2 Procggggdiqt_8aginaw Plant No. ofWSeeds in 2_gmst No. of Seeds/lb; Natural: 29,113 seed-balls/lb. 13 and over 2h.00 71 16,0h6 12 - 13 18.00 103 23,278 11 - 12 18.00 12h 28.02h 9i - 11 25.00 153 3h,578 9 - 92 1.11 203 h5,878 8 - 9 7.09 2&4 55,14h 7 - 8 2.00 320 (1 sample) 72,320 Trash 1.50 100.00 A. Overtl3 - after Burr l3 and over b.3h 70 (2 samphes) 15,820 12 - 13 42.60 77 17,h02 ll — 12 3h.78 80 18,080 35 -9%l 8.70 110 2h,860 7 : 8 ) 2.60 275 (1 sample) 62,150 Trash 6.2§_, 100.00 B. 0ver_l3_- after Pressure Plgtg 13 and over tr - - 12 - 13 tr - - ll - 12 2.68 85 (1 sample) 19,210 9% - 11 A6.h2 97 21,922 9 - 93 10.08 122 27.572 8 - 9 13.13 156 35.256 7 - 8 3.57 325 (1 sample) 73,450 Trash 2h.12 100.00 9. 13 - 7 before treatment 13 and over 1.0h 93 (1 sample) 21,018 12 - 13 25.77 100 22,600 11 - l2 21.6h 123 27,798 95 - 11 31.02 155 35,030 9 - 9% h.56 189 42.714 8 - 9 11.91 221 50,62t 7 " 8 1003 - .- Trash - 100.00 -11.. TABLE II (Continued) Sige (64thgfi) g No. of Segds in 2 gms. No. of Seeds/1b _p; l3_: 7 after Burr 12 and over 22.13 9h 21,2hh 95 - 11 36.89 152 34,352 8 - 92 13.93 226 51,076 7 "’ 8 1061+ - .- Trash 0.82 - - 100.00 E. 13 - lafter Presswe Plate 11 and over tr - - 9% - 11 26.67 121 28,021 8 - 9 28.00 189 h2,71h 7 - 8 , 1#.36 273 61,698 Trash 17.95 - - F. 0ver_9§ - befopegtgeatment 12 and over tr - - ll - 12 1.00 - - 95 - 11 98.00 106 23,956 8 " 9% 10m "' " G. Over 93g: after Pressugefiplatg 95 and over 85.10 109 2h,63h 8 - 9; 90162) 7 - 8 0.53) 137 30,962 TI'BSh #095 H. Processed: 37,373 seed-balls/lb. 9 - 91 15.00' 132 29,832 8 - 9 36.50 171 38.6h6 TraSh 0050 - " .Mgnogerm 2 gms. ‘ 213 18,138 -12- 0f the 2A percent of seed over l3/6t inch that passed into the first burr, only 2.6 percent was reduced to the size of the processed seed and h6.9h percent remained on the 12/6h inch sieve - see Table II(A). Table III shows that, of the 7A.5 percent of seed be- --mfi tween 7/6h and 13/6h inch that passed into fine second burr, only the fraction which remained on the 12/64 inch was re- duced, and.then by only h.6 percent. TABLE III Size (6gphs") 2 Before Burring_ %_After Burripg 12 and over 26.81 22.13 11 - 12 21.64 2h.59 9% - 11 31.02 36.89 8 - 9% 16.50 13.93 7 - 8 2.68 1.6h Trash 0.82 100.00 100.00 From these results it would appear that the function of the first and second burrs was merely to rub off some of the corners of the bigger seed-balls. As machines for reducing the size to less than 92/6h inch, they were not very efficient. The pressure plates showed much greater efficiency in :reducing large seed-balls to the required size, The first re- «iuced.the 90.42 percent that is larger than 92/64 inch in size. AlJnost one quarter of the weight of'material going into this -13- machine was discarded as trash. The second pressure plate is equally as effective, for of the 83.61 percent of seed over 95/6h inch in size, all but 26.67 percent was reduced to the desired size. This machine discarded about 18 percent of the weight of intake as trash. The results relating to the third pressure plate indi- cate that it was not set correctly, for of 98 percent of seed over 95/6h inch being fed into the machine only 12.9 percent was being reduced in size, the remaining 85.1 percent being) returned via the auger conveyor to the mill for further treat- ment. This had a depressing effect on the output of the plant and was, in fact, the limiting factor to the quantity of natural seed that could be dealt with in a day. It should also be noted that as processing progressed, seed density increased and the number of seed-balls in a given weight of a particular grade decreased, e.g. compare the 9/6L inch grade of natural seed with the same grade of processed seed. Seed density increased because much of the light corky husk had been removed in the process, thus giving a seed that would flow more regularly in planter units. The recovery of finished seed was estimated by the plant Operator to be somewhere in the region of 60 percent, by weight, of the natural seed fed into the hOpper. This compares favorably with results given by Tingley (7) in which the aver- age recovery from half a million pounds of natural seed was 60 percent with a peak recovery of 62.7h percent from 60,720 pounds of U. S. 15 seed. -14- QERMINATION l) Germination Trial Gennination trials were carried out in the greenhouse on samples of seed processed at Saginaw. Twenty-five seed-balls of each grade were planted at one inch intervals in rows two inches apart in clean sand. The seed-balls were covered with a quarter of an inch of sand and watered alternately with water and nutrient solution.. Three replications were made so that in all, one hun- dred seed-balls of each grade were under observation. Each replicate also included one row (25 seeds) of mono- germ seed for comparison with the multigerm U.S. A00. 2) Results Observations were made every day for fourteen days from the date of sowing in order to obtain a complete record of germination and.the number of sprouts produced by each seed- ball. These results are summarized in Table IV. TABLE IV Results of the Germination of Various Grades of Sugar Beet Seed to show the Germination Capacity and the number of Sprouts produced_per Seed—ball Group Size % of Seed-balls Giving 1,2,3,h, Percent Over 5 or 6 Sprouts <_ Germination MY. F223 .1. Z 2 F If .5. Natural 13 h 5 49 3o 11 - 1 96 12 h 12 6O 23 l - - 96 11 5' 25 50 20 - - - 95 9g 12 31 51 6 - - - 88 9 2h 28 42 6 - - - 76 8 27 32 38 3 - - - 73 7 AA 31 25 - - - - 56 Group Size Over 65mg: Over 13 9 after Pres. 8 Plate 7 l3 - 7 9 after 8 Pres. Plate 7 Processed 9 (9% - 7) 8 7 Monogerm -15- TABLE IV (Continued) % of Seed-balls Giving 1,2,3,A, Percent 5 or 6 Sprouts Germination ____None .1 Z 2 .9 15 37 36 2 - .. - 85 32 AS 20 3 - - - 68 75 22 3 - - - 25 12 28 5O 10 - - 85 19 27 A9 5 - - - g1 18 L3 37 1 l - 82 25 29 38 7 1 - 75 12 33 53 2 - - - 88 19 36 LA - 1 - - 81 13 77 9 l - - - 37 When these results are applied to the groups from which the grades were selected, i.e. natural, processed, over 13 after pressure plate, and 13-7 after pressure plate, they give the information compiled in Table V. Unlike the seeds of other major farm crops, sugar beet seed can produce up to six or seven young plants and conse- quently the germination percentage by itself gives no true indication as to the number of plants that a sample of seed will produce. Table VI gives the number of seed-balls in each grade that will give one, two, three, or four sprouts. This information is further elaborated in Table VII when the numbers of multigerm seeds are expressed as percentages of 'the total number of seeds, and of the number of viable seeds in each group. Sofia! o.sm mmN.c em mMH.ms atcwcccz c.Nm snm.s Nom.ws 1; 1: .1- owe N Na Nam .mH mac .Hc m.wN m-~ cccHa.ccta NOH. a Hm NHc. HN aHs. N: 6.0“ mum tccec Ra mm 31m mum in m.mN no.6 a o H. .. mH “1H6 mNsasH owsqNMI Namé wN owed 0343. TH mi. cchméonm 0mm.m mc NmN. .NH cmN. .mm o.ms o-m hoses cam.H mm mam. OH Nam. NN c.sm tc>c a 6 MH tc>o m .Hm med SENS loam H Hm ssmqmnii. Nacqsn o.mH m-m11 Noc- H mm «OH 4H 6:6. .mm m.cm o-m Rm. m 2. .Na. mH Nmm. mN 0.3 .250 a o comma-coed was N84 mama-SN on. on sea. H ,onqNN o.N m-mr So. H mm «Ho. m .31? H4. mum mas. cs mNo. N mam. ma 4.4 mad smo. H mm sac. .m men an o.mN HH mo NmN mo .30. m 30. .mm o.mH NH- HH scH cm OOH.4 mNN. MN o.mH NH-NH amH co Hmm m 30. 0H 0.3.. .88 s H Hch-pcz & oumnmsnmw no pm: on mumHHmM Iwwwmu mo & mocha Mo .DH H em .nHmmmmcm mmoamrewlr MMMNH nHEhmo mnmom no .oz eoHuwcHspco nHHmnupmmm mo .02 mo .02 opens mo w evwho macho > mqmHw comm mo .na H m.mo H.mmH o.mw m.mMH ©.moH m mom meson m UFHI asm.ms mmw.oc NN®.Nm ESPN. HHN.ms H . hem sanctum oww.Ha 0mm.hm oNo.mN was.om maH.mN chcH> mmH.ms Nos.ms ems-hm men-hm MHH.oN .nHNmmvmm dMHIMMm m utccm .doHumeHEHmo 00.5m ow.mm Om.H® md.Hm oa.cm Summocoz .m.m Locum 5 1 MH .m.m poems MH ac>o pomueuonm Hmuspmz sumac H> mqm<9 mpsommm anon to mouse q0391495 economm page memho some :« mHHmnuvmem mo popes: one TABLE VII 6;ng % of Seeds that will give g of Viable Seeds that will give Singles Doubles Epiples Quads Singles Doubles Triples quads Natural 2h.8 50.5 14.0 1.7 27.3 55.h 15.3 1.8 Processed 32.9 h5.9 3.3 0.6 39.8 55.5 h.0 0.7 Monogerm 77.0 8.9 0.09 - 88.5 10.3 0.11 - Over 13 ‘ after 36.8 22.8 1.9 - 59.8 37.0 3.2 - Pres.Plate 13 - 7 after 32.8 #5.0 h.5 0.3 39.7 5h.5 5.h 0.h Pres.Plate 3) Dipppssion of the Results In discussing the germination of sugar beet seed, it must be realized.that its value depends upon the characteristics that are desired. For instance, if high germination capacity is the primary objective the conclusions will be different to those drawn if the aim is to produce as many seeds as possible with only one germ. Table IV indicates a germination percentage of 96.0 for natural seed that is over l3/6h inch in size, but the fact that #2 percent of this grade produces three or'more sprouts per seed-ball makes it of doubtful use for current demands. Similarly, 88 percent of the seeds that germinate in the 7/6h - 8/6h inch grade of’the "over 13 after pressure plate" group, produce single sprouts, but the germination is too low at 25 percent. -19- The germination of natural seed falls rapidly as it de- creases in size until at 7/6A inch it is down to 56 percent. This agrees with the previously quoted findings of Price and Carsner (3). Table IV also shows that although the first burr and pressure plate were very effective in reducing the number of multigerm seed-balls, the treatment was so harsh that the germination was severly affected, particularly with the smaller grades. Germination was not appreciably affected by the second burr and pressure plate even though a considerable reduction was made in the number of seed-balls giving more than two sprouts. In considering the groups from which the grades were selected, it was observed that there were 25 percent more seed- balls in one pound of processed seed than in the same weight of natural seed, due to the elimination of the coarser grades. Monogerm seed contained 65 percent more seed units per pound but had the same germination as natural seed. Table VI shows that the number of sprouts per pound of seed actually increased slightly as a result of processing, the number of singles being doubled and the number of triples being reduced by two—thirds. When these results are expressed on a percentage basis, as in Table VII, the differences are not as great, for, whereas natural seed has a make-up of 75 single or double germ seeds in every 100 seed-balls, the pro- cessed seed has 79; and where natural seed has 25 percent of singles, processed seed has 32 percent. When germination is taken into account, the highest num- ber of singles in the viable seed is found, as might be ex- pected, in the monogerm seed with the "over 13 after pressure plate" taking second place with almost 60 percent singles. Both the finished processed seed and the "13-7 after pressure plate" group contain AS percent of double germ seed. Frakes (A) has shown that yields of sugar beets are not affected by leav- ing up to thirty percent of‘doubles in the crep, so, after alu lowing for thinning, it is reasonable to suppose that a seed- ling stand with 15 percent doubles will not appreciably reduce the yield of the crop. CONCLUSIONS The objects of processing sugar beet seed can be stated as follows: 1) To convert a seed that is variable in size, shape and germination capacity into something that is uniform in size, regular in shape and reliable in germination. 2) To obtain as high a degree of uniformity as possible in regard to the number of sprouts that a seed-ball will produce. 3) To reduce the number of sprouts per seed-ball to as low a number as possible without seriously impairing the germination. A) To achieve the three previous aims with as high a de- gree of efficiency as possible, i.e. without excessive loss of viable units. Results obtained from processing and germinating sugar beet seed of variety U.S. 100 indicate that the processing plant of the Farmers and Manufacturers Beet Sugar Association at Saginaw was producing seed with the following characteris- tics: 1) It was between 7/61 inch and 93/61 inch in size. 2) Less than 1 percent of the seed-balls gave three or more sprouts as compared to nearly 16 percent in natural seed. 3) The number of seed units giving single sprouts was 8.0 percent higher than in natural seed with a loss of only 1 percent in germination. Table VIII shows that by grading alone, the number of seed units giving single Sprouts can be increased by 6 percent but as only 13.5 percent of natural seed falls into grades that are less than 9/61 inch in size, the losses involved in discarding the larger grades would be too great to warrant the adoption of such a practice. TABLE 1131 The percentagg of seeds producing single sprouts that remain after eachgradevis sieved off %'By Remove Grade Over 13 After 13-7 After Pro- Wt. Larger Than Natural Pressure Plate Pres. Plate cessed 21.0 13/61" 21.8 18.0 12/61" 26.6 .18.0 11/61" 29.5 25.0 93/61" 30.9 ( 9/61" 30.7 36.8 32.8 32.1 13.5 ( 8/61" 31.7 36.7 33.8 31.2 ( 7/61" 31.0 22.0 13.0 36.0 Similarly, if those seed units less than 8/6h inch in size from the "13 — 7 after pressure plate" group are used, h3 percent of singles can be obtained. However, as this grade amounts to only 1h.3 percent of the group (see Table II), losses involved would be too great to justify its use. Complete processing raises the number of singles from - -.__-_:.‘m .D hl . 2h.8 to 32.h percent and, with an estimated recovery of 60 percent, the numbers of multigerm seeds are reduced and single ) germ seeds increased without involving too great a loss in the k process. A) The efficiency of processing with a 60 percent re- covery is comparable with the efficiency of other processing plants. In fact, if the number of viable seeds in a pound of processed seed is compared with the number of viable seeds in the natural seed needed to produce it (see Table VI), the re- covery in terms of viable units is 72.6 percent e.g. from Table VI. 1 lb. of natural seed contains 25,165 viable units. Recovery is estimated at 60 percent, therefore, 1 lb. natural seed gives 0.6 lb. of processed seed. Since 1 lb. of processed seed contains 30,h55 viable units, the number of viable units in seed processed from 1 lb. of natural seed is 30,L55 x 0.6 or 18,273. Therefore, the recovery of viable units equals %%L%%% i or 72.67 percent. Lu! PART II PLANTING 8821811811119. The establishment of a sugar beet cr0p that will produce the maximum yield of roots and sugar per acre is the result of a number of individual but closely related operations. Good viable seed must be planted in such a way that it will germinate evenly and in such a pattern that an optimum stand can be obtained with the minimum of hoeing and thinning. The characteristic non-uniform field emergence of sugar beet seedlings is the result of three different elements in the sowing of the cr0p: (1) the lack of uniformity in soil moisture, soil temperature, etc., (2) the multigerm nature of natural seed and (3) the rough, casual method by which the seed is planted. Qualities involved in evaluating seed, such as size, viability, and the occurence of multigerm units are discussed elsewhere in this treatise. The method of sowing, however, has received very little consideration and, according to Andrews (8), there have been no major improvements for the precision planting of beet seed in the past thirty-five years. The one exception to the lack of planter improvement has been the deve10pment of the Milton drill. This machine is a precision drill which will discharge seed evenly from seed cups traveling one inch above the bottom of the seed furrow. -23- -2h- When this method of seed delivery is compared with that of the conventional type of planter in which the seed bounces down two to three feet of seed tube and then rolls anywhere over four to five inches of seed furrow, the improvement will be obvious. Other planters of the precision type have been recently introduced by other implement manufacturers. The planting of seed and the subsequent mechanical oper- ations necessary for the establishment of a good crop are very closely inter-related and present many complex problems to the agronomist and agricultural engineer. The over-all problem in the establishment of an optimum stand of sugar beets is one of Space relationships. Together, row width and the Spacing of plants within the row, form the pattern in which plants are grown in the field. A great deal of research work and experimentation has been carried out to determine the ideal pattern or lay-out for optimum and maxi- mum production. REVIEW OP_LIZ§RATUR§ Problems of Space relationships in sugar beet cr0ps have occupied the attentions of agronomists since the very begin- nings of sugar beet culture. As farming techniques and prac- tices have improved and developed, research work has increased and a vast amount of information is available on experiments that have been carried out in the United States, Great Britain and Europe. -25- The problem in sugar beets consists of a series of inter- locking phases involving plant populations, field patterns, compensation for missing plants, and tolerance for multiple seedlings. Plant Populations: The results of research work are consistent in showing the value of high plant populations per acre. Doxtator (9) at Rocky Ford, Colorado, obtained the highest yields from populations of 25,000 to 35,000 plants per acre but pointed out that these were very difficult to obtain in 28 inch rows. The required 8 inch spacing caused the production of many small beets that were difficult to harvest and, when hand labor was used, probably involved a greater expenditure of labor and time than the increase in crop warranted. Tolman (10 & 11) gives the standard recommended population in Utah as around 25,000 beets per acre and found in almost every case that yields decreased as the plant p0pulation was reduced below this figure. ' Deming (12) states that with uniform distribution of plants, populations moderately in excess of the optimum of about 26,000 plants per acre will produce approximately a full crop of sugar beets. Rayns (13) working in England gives the optimum popula- tion as 30,000 plants per acre. However, it seems that as plant populations are increased beyond 30,000 per acre, there is a marked reduction in the size , I -40- of individual roots Which causes additional difficulties at harvest time. Row Width: The width of rows in which sugar beet should be planted has been the subject of extensive investigations. Tolman (ll), Doxtator (9), Grey and Volk (1h), Murphy and Carsner (15), Deming (16), and Skuderna (17) have all reported on this pro- blem. The concensus of opinion seems to be that rows widely spaced cause a decrease in both the total weight of the beets harvested and in the percentage of sucrose, regardless of the total plant population. Skuderna states that in the Red River Valley area of Minnesota where annual rainfall is less than twenty inches per annum, row widths greater than 22 inches caused a depression in beet yields and in sucrose percentage. Doxtator (9) asserts that yields per acre of beets and sugar were highest in Colorado when planted in 20 inch rows at each of three p0pulation levels - 22,000, 26,000, and 30,000. This row width gave the highest yields for Deming (16) although the lowest yields from 22 inch and 2h inch rows were only 500 pounds, or less, of sugar per acre than the check so that convenience and savings in time may more than compensate for the reduction. Grey and Volk (14) in trials with rows at 22, 28, and ‘36 inches wide, obtained the highest yields from the 22 inch 'width. Murphy and Eubanks (15) in comparing row widths vary— n -¢7- ing from 22 to AA inches, state that while rows wider than 22 inches may be desirable for harvesting operations, losses of up to six tons of beets per acre are incurred when the row width reaches hh inches. It is interesting to note that in spite of overwhelming evidence in favor of planting in narrow rows, the standard practice in Michigan is one of growing sugar beets in 28 inch rows because that width facilitates over-all farm operations. For example, 20 inch rows give 26,226 linear feet of row per acre to be hoed, thinned, cultivated, and harvested, as against only 18,668 linear feet from 28 inch rows. Spgcing: The problem of the distance at which sugar beets should be spaced in the row is one that is not solved by dividing the intended plant population by the row width. Garner and Sanders (18) working in England on "Experiments in the Spacing of Sugar Beet," reported in 1939 and again in 1940 that wide row spac- ing could not be compensated by narrower spacing within the rows. They gave the minimum spacing as 9 inches. Deming (12) working in Colorado obtained his highest yields from 20 inch rows with 100 plants to every one hundred feet of row and found that reductions in the stand below a uniformly distributed 100 resulted in a reduction in yield. These results were confirmed in the same year (1966) by Tol- xnan (10) in Utah who went so far as to say that spacing closer than 12 inches was not beneficial regardless of row width, I—rnc‘flL'flA-‘l "4‘3 " 1 « I whether 20, 26, 32, or 38 inches. The results of further work on spacing by Tolman (11) agree with those of his earlier re- ports and he states that maximum yields are obtainable from 20 inch rows at 12 inch spacings. Skuderna (7) reporting on experiments carried out in Minnesota from 1962-46 states that the highest yield was ob- tained from 15 inch Spacings in 22 inch rows and that with wider rows, reduced Spacing did not result in any improvement ‘in yields. In Michigan, Frakes (19) found that there was no signifi- cant difference from beets planted in 28 inch rows when spaced at 8, 10, 12, and 16 inches, but that there was a reduction in yield when spacing was reduced to six inches. Gray and Volk (16) in Ohio reported in 1951 that in trials with spacings of h, 8, 12, and 16 inches in rows 28 and 35 inches apart the A inch Spacing gave the lowest yields. In comparing beets grown in rows 22 inches wide and spaced at 12 inches with beets grown in rows 36 inches wide and spaced at 6 inches, they obtained the highest yield from the narrower row width and wider spacing. Reeve and Reeve (20) also working in Michigan, found that the highest yields of sugar per acre were obtained from 12 inch spacings. Summing up, it would seem that spacial allotments which approach the square are more efficient than those that are ex- tremely rectangular. Yields decrease progressively as the ~29— Space allotment becomes more rectangular so that distorting the Space allotment has more effect on yield than either in- creasing or decreasing it. Multiple_9cgupgncyz The long-held conception of a perfect stand of sugar beets was of single plants spaced uniformly in rows of the Optimum width. Yet as long ago as 1935, Brewbaker and Deming (21) stated that even if 25 percent of the stand was made up of doubles, root yields were not significantly lowered. They concluded that yields were determined by the pattern of plants and not by single plants. Deming (12) confirmed these re- sults at Fort Collins, Colorado, and reported in 1946 that there was no difference in yield between 100 single-plant hills per 100 feet of row, and 100 hills with 25 percent doubles per 100 feet of row. In comparing single plants Spaced 10 inches apart with doubles thinned to 20 inches, Ryser and Owen (22) reported in 19h6 that there was a small and possibly significant increase in yield from the single plants. However, they pointed out that if the difference was small with 100 percent doubles, it ‘would be insignificant with the less than 100 percent doubles .met with in ordinary field practice. Frakes (19) in experiments with 0, 10, 20, and 30 per- cent doubles, found that the effect on the yield of roots and available sugar*was not significant. Additional evidence is given by Reeve and Reeve (20) who -30- not only found that doubles had no effect on yield but state that the ideal stand of sugar beets is one which contains one hundred beet-containing blocks. more or less irregularly spaced, per 100 feet of row. Compensation for Missing Plants: There appears to be some divergence of opinion as to the effect of misses in a sugar beet stand. Brewbaker and Deming (21) in 1935 stated that eight beets surrounding a blank Space in 20 by 12 inch Spacing, were so increased in weight that there was a compensation of 96.2 percent of the loss due to a single missing beet. This view was confirmed in 1951 by Rayns (13) who stated that 86% of the loss in yield caused by a missing plant is compensated for by its neighbor. However, Deming (23) working in Colorado reported in 1950 that additional plants present in multiple-plant hills may have some adverse effect on yields and that these plants in no way compensate for misses in the stand. This review of literature covers only a small portion of the mass of experimental work that has been carried out on the space relationships of sugar beet. As it appears now, it would seem that in so far as final yields are concerned, the particular row width or Spacing is relatively unimportant. The important factor is more one of uniformity of stand, measured as beet-containing inches per hundred feet of row. Previously held notions that doubles are undesirable will have to be forgotten, the idea of achieving -31- perfection by having plants spaced regularly at twelve-inch intervals will have to be replaced by an aim of having twelve beet-containing inches in twelve feet of row, and while row widths of thirty-eight and forty-four inches are far too wide for maximum yields the previously recommended optimum row width of twenty inches will have to be modified to allow for the efficient utilization of modern machinery. FIELD OBSERVATIONS The object of this study was to compare current practice in Michigan with the findings and recommendations of research work described in the foregoing review of literature. The limited amount of time available prevented the exe- cution of any critical trials but observations were made on a number of fields in Tuscola and Huron counties where pre- cision drilling and space planting Operations had been per- formed on a field scale. Fields reported in these case studies had all been planted with seed of variety U.S. 400, processed to between 7/6h and 10/6h of an inch in diameter. Seed of this size contains ap- proximately 37,LOO seed-balls per pound and with a germina- tion capacity of 81.5 percent is capable of producing 192,000 seedlings per acre when planted at a rate of four pounds per acre. According to results given in Part I of this treatise, this seeding could be expected to give approximately 49,216 singles, 6h,250 doubles and 6,6h0 triples per acre. Planting 'was conducted in rows 28 inches wide so that in terms of hun- -32- dred feet row lengths, the total number of possible plants would be 1,028, including 265 singles, 344 doubles and 25 triples. Field 1. Sugar beet seed was planted with a Palsgrove planter, em- bodying the Milton precision drill, at two different seed rates; viz, normal - at four pounds per acre, and space plant- ing - with one seed every six inches at one pound per acre. Observations made on April 28th gave the flollowing in- formation: Normal Planting Seed planted at four pounds per acre appeared to germi- nate more rapidly than space-planted seed. Counts showed an average of 771 plants per hundred feet of row in an even stand. Space Planting On germination, space-planted seed gave the following counts per hundred feet of row: 78 groups, including 24 multiples (30.7%), a total of 101 plants 66 groups, including 24 multiples (36.4%), a total of 90 plants 69 groups, including 27 multiples (34.8%), a total of 96 plants. These figures give a mean of 71 groups, including 25 multi- ples (34.0%), to give a total of 96 plants. Seed was planted at a rate of two hundred seeds per hun-