; THE mm. 3; mm 3014mm 8N m *5 MERRY '3? WURE 5ND EMMURE ”TV” THEszs FOR DEGREE or: m. s. Ina" ”n-mw-r ~ r A , ._ an. mun-runs” nan an“... . ‘ ,y 3 - ,. -. r . .,...., . LARNtSs 508:?!“ ‘mmzLER a '5 i V rs '5 3 '1 ‘1 9 c. b g 5 my. $518 I 3 3 8 '7 5 T P Q ~ V LIBRARY Michigan State University PLACE IN RETURN BOX to remove this checkout from your record. To AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 5’08 KIProj/Acc8Pms/ClRC/DateDueindd i Elliibl. II 3. I . , Lil! III. I. (lulu .‘elltk ’0‘-‘I , ‘ .l . u o u _ 3"- I "~.., 5m . , , , . 5 kWh-”mm '- =3. 1-:~a~;..u'né“{ *—-*-rr’ *“ ng §§FECT or smoaaes coNDtmIoNs on THE vmulfl DE @393me move; 20 TATO ES A Thesis Prepared by ERNEST JOSEPH WE in partial fulfillment of the requirements for the Degree of Master of Science, Department of Farm Crops. CHIGAH STATE WLLEGE 0E AGRICULTUhE AND APPLIED SCIENCE 1928. THEle 13% 2”? 2» THE; THE EFFECT on STORAGE commune on THE VIABILITY 019 MATURE AND IMTURE SEED POTATOES. ”104203? ACKNO WLEDGMEEI 'l‘ The writer wishes to acknowledge the hearty co-oPeration that he has received from those who have assisted.with this thesis; Professor E. E. Down for the assistance in the interpretation of the data, also Professor J. P. Go: and H. 0. Moore for the help in. the procedure and cultural methods used in the experiment. He also wishes to thank the one! that had charge of the storage where the lots of potatoes were etc red. I. II. III. IV. V. VI. VII. VIII. IX. 0011 TEN ‘I‘S Review of Literature Introauotion Experimental Methods Greenhouse Test Field Plat Technique Discussion of Experimental Data 1. Mature vs. Immature Seed Potatoes Conditions of Seed After Storage Number of Stalks Per Hill Experiment Conclusions Bibliography 3! 15 18 18 35 45 58 59 -1— nLVIEW 0E LITERATJhE. H. P. Hutchinson, Jour. Bd. Agr. (London) Ho. 6, pp 529-539 concludes that immature seed is superior because, (1) In using immature tubers for seed the largest tubers of the most productive plants will naturally be selected, thus resulting in increased yields, or, at least in.maintaining previous yields. (2) The cortex of immature tubers is thinner than. that of mature tubers thus lessening the check or imbibition of water from without, which is necessary during the early stages of growth. (5) The amount and available ability of the reserve plant food Inaterial may be greater in immature tubers than in. the mature ones. (4) The length of time of storage Inay materially affect the amount anc.form of plant food material which would favor immature tubers due to the longer period of storage which they are subjected to. The use of immature tubers fer seed promotes earliness, vigor and an ability to form tubers under an adverse seasonal condition. W. T. Macoun reports in Bulletin.No. 90 that the Department of Agriculture for Ireland makes this recommendation: "Immature seed--It is recognized that seed from crops lifted before they fully mature will I shit-e to.“ IV -2- produce more vigorous plants, and consequently, heavier yields than seed from crOps which have been allowed to become fully ripe. In Ireland, this applies more particularly, perhaps, to early varieties, but it is a point worthy of notice by growers of seed potatoes. In 1906, Stewart, University Leeds and York- shire Council Agr. Ed. (pamphlet) 63, p 14-16, reports results from a study of the relative merits of immature and mature seed potatoes. The vines of those harvested as immature were green and.those for mature were ripe and the skin of the tuber was tough indicating maturity. In 1905 tun average of five varieties showed less than 6 per cent increase in yield of immature over mature whole seed. Ramsay, Department of Agriculture, Victoria 15: 540-348 in 1914-15 compared whole and cut seed of both immature and mature tubers. Immature whole sets yielded.at the rate of 207 bushels per acre and mature sets only 100 bushels. In the case of the cut sets there was a much greater difference in favor of immature sets - 178.5 to 65.6. The whole immature sets showed an increase of 58 per cent and the cut sets more than.l72 per cent. 1921-22 test showed a difference of 41 per cent; 1925 test showed 65 per cent, and in 1925 nearly 26 per cent. All these differences in favor of immature seed are sufficiently large to be significant. Dunlop, Midland.Agricultural and Dairy College heport 1914: 21-22, and 1915: 42, reported that immature and mature seed of the Factor Variety were compared, the immature seed stock yielded at the rate of 466.7 bushels per acre and the ripe seed produced 456.7 bushels. In 1915 a similar comparison was made of the King Edward.variety. The immature seed was dug September 9, 1914 and the ripe seed October 15, 1914. The immature seed produced 106 per cent larger yield than the mature seed. The experience of Helmer, Canada Experimental. Farm Station, Summerland, B. 0., Report September 1926: 60-61 with immature and mature seed.was distinctly in favor of mature seed. Davidson, Jour. Department of’Lands and Agriculture Ireland 24: 574-425 suggests that ex- periments have proved that there is nothing to the idea that immature seed is superior to mature seed StOCke In their reports of field crops Appleman, N} J} Agricultural Experiment Station.Annual Report 1920, 41: 251-256 and Cox, H. Y. Agricultural .Experiment Station Annual Report 1920, 41: 207-210 1, [xi - 1.1.. -4... state that the immature seed had better germination and the vigor throughout the growing season was better than northern grown seed. The immature tubers set more tubers per plant, but they averaged smaller and more rot was present. William Stuart in "Source, Character and Treatment of Potato Sets", U. S. D. A., Washington, D. 0., Technical Bulletin No. 5, p 25-24, summarizes the work of immature and mature seed as affecting the yield of potatoes. A review of experimental data disclosed very little difference between mature and immature seed potatoes, but there is sufficient evidence to support that immature seed is slightly better than mature seed. The eXperimental results from Norfolk, Va., studies show that in the tests of only two seasons of the five were larger yields of primes obtained from immature seed. The Caribou, Maine data showed a slight gain in primes from mature seed and a trifle larger in- crease in total yield. Based on three year averages, both medium mature and immature seed stock gave larger yields than mature stock at Presque Isle, Maine. r..>fi|i|r.’ The percentage of disease was larger in immature seed when immaturity was obtained from late plantings, and the reverse was found to be true when immaturity was the results of early harve s ting . In the Greeley, Colorado experiments where immaturity was the result of early harvesting, larger yields were obtained in three out of five seasons from immature seed. The difference, however, was not sufficiently great to be convincing, as the average increase for the five year period for primes was only 5.7 bushels and for total yield only 5.1 bushel. At Jerome, Idaho, the average gains in acre yields of primes were so strikingly large as to preclude the possibility of its being due to acci dental variati on. Appleman and miller, Journal of Agricultural Research 55: 569-577 report results that the ripening and maturity processes may continue during Storage. No chemical or physiological basis has revealed any superiority of immature seed over Imature potatoes for seed. The authors express their belief that where immature tubers have outyielded mature may be accounted for by the mature having greater amounts of degeneration diseases. INTRLDUCTILN: niich igan farmers on the average harvest 505,100 acres of potatoes each season yielding 101 bushels per acre making a total production of 50,585,000 bushels. The average price for a period of 9 years, 1918-1917, has been hinety cents (90¢) a bushel making the potato crop worth Twenty-five million seven hundred sixty- nine thousand dollars ($25,769,000) each year. The state is divided into two parts as far as the production of seed potatoes and table stock is concerned. The northern part of the state procuces a greater part of the 500,000 bushels of certified seed, while the southern half of the Lower Peninsula produces the greater part of the table stock potatoes. Certified seed is stored by the grower and delivery is made in early spring. The potatoes are in many cases stored under poor conditions in house cellars, with and without furnaces, in storages above ground made of wooden frame structures where the temperature and humidity varies With weather conditions, in pit storages and Btorages that are built in the side of a hill. if]! It” I i’ -7- Better potato production demands that the growers plant good seed that is free from disease and in such condition that it will pro- duce good vigorous plants. Immature seed harvest- ed when the plants are still'green and the skin feathers up is claimed by Sutton and Sons of Reading, England and I. T. Ramsey of the Depart- ment of Agriculture of Victoria, to be better for seed as it gives increased yields. In the United States a few experiments lave shown im- mature seed to be better, but most of the Experiment Station Workers report negative results as to immature seed yielding any better than mature seed. LAP” ‘ ER DuENl‘aL MLTHCDS. This thesis is based on an experiment con- ducted to show if there is a difference between mature and immature potatoes stored under various conditions. Storage conditions varied in this am eriment as they vary in the different potato seed storages of the state. The data here given were secured from observations made of plate grown at the Michigan Experiment Station. [lil'lilllir .III. | Storage space was obtained.where the desired conditions could be located. It was necessary to utilize some Space in a house cellar also some space in a cold storage where the different temperatures desired could be maintained. Russet Rural potatoes that had.been planted at the College one year were used. The seed.was certified in 1926 and was of the same strain and practically free from any noticeable disease. The first lot of seed.was planted June 8, 1926 and and the second lot of seed was planted July 2, 1926. Both lots of seed.were harvested after frost had killed the vines, September 22, 1926. The early planting showed.maturity in the vine growth Whereas the later planting had vines that were still green at the time of frost. The potatoes from the later planting were much smaller than the potatoes from the earlier planting. The seed from the early planting was designated as mature seed. The seed from the later planting was designated.as immature seed. Both the mature and immature seed were stored under conditions described in the following paragraphs. The seed potatoes were divided into lots of fifty and one hundred pounds and placed in sacks. Some of the sacks were placed in tight containers while others were stored in the center of the bin and in special bins. The following are the different ways in which the seed potatoes were stored: 1. Root cellar storage at the College Storage cellar. Tubers were stored in the open, also stored in closed containers. 2. Cold storage at Michigan.Butter and Egg Cold Storage, Lansing. 56° F. open storage also storage in closed containers. 5. Cold Storage at.MichiganIButter and Egg, Lansing 52° F. open storage also storage in closed containers. 4. High temperature storage (40-70°F-) Storage was in a room next to a furnace in a house cellar. 5. Pit storage in a sand hill near the College root cellar. -10- As many storage conditions were selected as the writer has observed being used by growers. The chief object was to test the viability of mature and immature seed when stored under differ- ent c ondi ti ons . In all cases the lots of potatoes were stored in burlap sacks for convenience in handling. -11- Figure I. This Photograph shows the type of closed container used in the experiment. -12- Immature and mature seed was stored under all the conditions named. Records were taken including notes on temperature and moisture conditions. Photographs were made May 10, 1927 of the different lots when removed from storage to show the comparative dormancy of the seed. The seed was treated with corrosive sub- limate, four ounces to thirty gallons of water for thirty minutes, and left for two weeks before planting for the potatoes to green sprout. The seed stored at low temperature would be more likely to have the rest period broken by the green sprouting and would start to growing immediately providing the potatoes had not been injured.by the storage treatment. GREENHCUSE TLST. An extra supply of potatoes was stored.et the.hichigan State College root cellar for green- house planting. Each month beginning with November and ending with April, plantings of mature and im- mature seed.were made in eight inch pots buried in soil on the greenhouse bench. [kit I -13.. The weight of each tuber was taken and the date that the first sprout appeared in each pot was recorded. The general vigor of the sprouts was recorded by means of photographs. EILLD PLAT TSCHHIQUE. The lots of seed were planted in plate at the College SXperiment Station. Each lot was planted in two replications, that is, three plate, the original and two other plantings. it is advisable to plant at least four replications, but owing to the limited supply of seed only two replications were made. The rows were fifty-six hills long and the hills were epaced eighteen inches in the row with the rows spaced thirty-six inches apart. The seed was cut into uniform pieces averaging one and one-half to two ounces in weight. Seed used.for the check plate was obtained from a single tuber strain developed by the.Michigan State College in 1924. Check rows were planted on the outside as borders. The second row of the plat was planted with check seed which was harvested and considered as the outside check. Mature seed was planted next to the check then followed a row of immature seed followed by another check I'W. Figure II. mama Rwanda moon ooHHmH Hssmddwo wooa cmwwmu oUcow Emddao mpd mdoamme Hssmdnuo mwd mdoammo deo o Blocgdflgmber I Mame amddHo wood ooHHmH Healdnua wood oowwmfl WdOo I I r 6 m N k c 0 1 B ouoow HBBmdfiuo mpa mdoammn «duo mud mdoammo ovoow Hssmdsao weed ooHHmH Emd¢H0.woow omuumu E macaw andsuo mus adoapMe Hssmnfiao wpd mdoapmn wan. Block Number III -16- Figure 2 shows in detail how the lots of seed were planted. In.block No. 2 the mature seed in the root cellar storage was put on the other side of the test plat and the other rows following the mature root cellar storage in Block.No. 2 were planted as in Block No. 1. Block No. 5 had.the rows arranged.so that lots of seed having the same storage treatment were in no case directly in line with each other. The mature and.immature seed planted between two checks represented a single storage condition. The mature and immature seed between the first two checks in block No. l was stored in the same storage, namely College root cellar. The plats were alternated according to the method of plat planting recommended.by the Plant Breeding Section of the Farm Crops Department of Michigan State College. Records of the germination of each row were taken at three different times during the first six weeks of growth. At the last germination count a record.was made of the number of weak hills in each row. When the plants were twelve inches high the number of stalks was recorded. The hills having one,two, three or more stalks were averaged separately and a comparison of the number of one, two, -17.. three or more stalk hills was made. Culture and spraying work was carried on the same as they would be in a field of potatoes grown for certified seed. The vines were sprayed seven times with a 4-4-50 mixture of bordeaux. Calcium arsenate was used in the first two sprays to kill Colorado Potato Beetles. The potatoes were cultivated a sufficient number of times to insure weed control. The plats were harvested on the 25th and 26th of September. Each lot was graded and weigh- ed separately. The grades were U. S. No. 1; U. S. No. 2 and culls. The total weight of each lot was recorded, the probable error and results were determined and are taken up in a discussion of the experimental data. ~18- DISCUSSILN LE ELEEhIMLNTAL DATA. There are two phases of the eXperimental data connected with this work. Cne is the com- parison of mature and immature seed and the other is the testing of the seed stored under the different storage conditions. Both phases are worked out in detail and a discussion of each is here presented. 1. Mature vs. Immature seed potatoes. Mature and immature seed were stored and planted under the same conditions and a comparison of the yields and the general vigor of each lot was determined. Eight tubers each from the mature and immature seed were planted each month from November to April in pots in the greenhouse. Notes were taken on the time the plants appeared above ground. Table I. shows a comparison of the mature and immature seed in the planting made Novanber 4. Table I shows the notes that were taken from the planting. It is quite evident that mature seed started earlier than the immature seed, also the vigor of the plants in.the more mature seed was better. The greater vigor of the mature seed as evidenced by the November 4 planting is no doubt explained by the eXperiments of C. O. Appleman, Journal of Agricultural Research 35: 569-577, who made a chemical analysis of mature and immature potatoes. His conclusions were that at harvest time the mature and immature potatoes differ chemically, the immature potatoes in the fall having more proteins than the mature seed. Toward spring, however, the mature and immature potatoes are practically the same, containing equal amounts of starch, sugar and other compounds. Dr. Appleman concludes that there should be no difference between the mature and immature seed. John Bushnell of the Ohio Agricultural Experiment Station in the Bimonthly Bulletin, Volume XII, No. 5, reports that a temperature storage of 38° is best for seed potatoes. Potatoes were planted from a storage where the temperature register- 0‘1 38° F. in comparison with potatoes stored in a commercial cold storage held at 35° F. The seed stored at 38° F. germinated more rapidly and it consistently yielded more than the cold storage seed. -21- Time of Sprouting of.uature and.Immature Tubers Planted November 4., 1927. Table I. 'Emm.’ """"" Email}. """""""" ' £3?"”§§I飧"""”522;"""Ezéigfi """"" 53573?” No. of qt of appear- tubers appear- tubers snce ounces snee ounces 1 1 Jan. 18 4 Feb. 3 2 6 Feb. 14 4 Feb. 23 3 4 Jan. 18 3.6 Mar. 11 4 4 Feb. 4 3.6 Jan. 18 5 8 Feb. 17 6 Jan. 20 6 8 Jan. 26 7 Feb. 17 7 7 Feb. 2 7 Jan. 20 *8 6 Jan. 17 6 Feb. 16 ‘ The sprout in this pot came up, but remained.short and.never grew. N0 disease apparent, likely due to the soil being packed too hard. -~- a... . .-. -. . ,_... . .. . -gn—g‘-.......~-a -«eoro— . u ‘ ... . a _, .., ~------,., 9 - --l--~-o--o- v<-—~«-'-C-0 . , _ i _ - ‘ I ' .. - -‘ ’ . ,' .- '. 4‘-‘*.CO‘-'-o—.‘--O—v-A-rr o .---“‘-°‘~.'.--—<-I . .e. C . ‘ . . . . I . ‘ . I | - e . a. l L- . b d . ' I . I “--O‘--‘.-‘-AQ-‘rvufl‘l...----..----—--‘--e-O'C-‘-~O“-~. I _.— ev . o— k ‘_ ~ Q . a -. -22- Time of Sprouting of each Individual Tuber Planted December 4, 1927. from;Msture and Immature seed. Table 11. ““"“‘i;;;;;"’ """"""" MES.” """""" £3?" {aEIERE'm’BQZi """" fi:’i;£2"""i€2§’3§ """ No. of - of of appear- tubers appear- tubers anoe O uncee 81100 ounces 1 10 Feb. 23 7 Feb. 6 a 6 Jan. 26 e m. '14 3 6 Feb. 16 7 Feb. 17 4 6 Feb. 26 7 Feb. 17 6 d Feb. 28 6 Decayed 6 3 Feb. 16 6 Feb. 28 7 d Jan. 26 4 Feb. 14 8 Feb. 16 4 Feb. 14 . - a. .n J . g . . — ~. .- a .-”.<.—. a .. O as. 4-Ov'a- .0“ O o..a-- ewe - ,4 -~--.Auv, g... -... . .— - . a - --‘.. -~~‘A-.«c..,.-.-.o -‘J.-- .. - . . . . c‘ " fir . - a.-....-h.p - , - ~-‘A-- n nie- .i . . . u D . ' . -a- 0-. e- .n.—.—-.— "U‘H.--’ .r“~'- en up “---".c.- ““a* z . O . --.-o“-C--- . L -. .' e I e e ... i O K-) .vl‘-'-O----o‘ -23- Time of Sprouting of each Individual Tuber Planted January 4, 1927, from Nature and Immature seed. Table III. "mm.mmam. """"""" 3332"”'fi:2§£§"""5;22 """" fiziéfii """ 33573?" No. of of of appear- tubers appear- tubers ance ounces ance ounces 1 4 Mar. 1 6 liar. 1 2 6 Feb. 26 6 Mar. 6 3 4 liar. l. 6.6 Mar. 10 4 6 Mar. 6 4.6 Mar. 1 6 3 liar. l 3.6 liar. l 6 4.5 Mar. 1 5 Mar. '7 3.6 liar. 1 4 liar. 1 8 3.6 Feb. 26 4 Feb. 26 H... -—..... .0..- -1. -24- Time of Sprouting of each Individual Tuber Planted February 4, 1937, from.Mature and Immature seed. Date of appear- ance Table IV. Mature Pot Weight Date No. of ,of tubers appear- ounces ance 1 3 .nar. 28 2 3 Apr. 3 3 6 Mar. 28 4 7 Apr. 4 6 6 Apr. 1 6 8 Apr. 6 7 5 Mar. 28 8 3 Mar. 28 e» -e 0- es 9» a: -e to Mar. 28 Decsyed Ear. 28 Ear. 28 liar. 28 Apr. 1 Mar. 27 Mar. 28 _. - I... -,. .. .V......... -1- . -..-.~ -..‘..-—-——.--a----'.-.-o any»... - O ' <- u v..— . -iom—o -.. .OO--~-H.‘ - o.‘ .-_ 4... n .v--’.v-. - .g- . ~‘ - . - \ t - _,. . . I I .0 k ' u - —.. ._ 4.‘. u .a... .0..-»- u-o—c.-.4-.._. a..- .—-4‘--.. ..O“ u‘... on...005 0.. fl 5' ‘ I .- o x; . . . .. v1 -‘---oo—~n-o-..A...-v.e-‘~.‘—-q—.unno.-.—'~O¢-a--‘0-----~.9—---‘. -25- Time of Sprouting of each Individual Tuber Planted March 4, 1927, from nature and.Immature seed. Table'V. ”"""EKE’""'”’"""”E22152 """""" 1332” """" ”BQEZ‘SE"""""”'B;Z;'SE" """" ' No. appearance appearance 1 April 11 April 11 2 April 12 April 16 3 April 17 April 16 4 April 18 April 18 6 April 12 April 22 6 April 12 April 18 7 April 9 April 9 8 April 11 April 19 4 - - a. s- -. .a. -~- -. --- ¢go -26- Time of Sprouting of each Individual Tuber Planted April 4, 1927, from.Mature and Immature seed. Table'VI. "””"’fi£§$§”“""”"‘"”’BESS?” """" ESE'""§Z'{§£Z”'”1322."""’F«2§E£§""”BE§§‘SE"m No. of ~ 01- of appear- tubers appear- tubers ance ounces ance ounces 1 3 May 2 6 May 7 z 2 my. 3 a May 4. 3 3 Apr. 22 3 Decayed 4 2 Apr. 29 2 Lnay 6 6 4 :Msy 2 3 luay 9 6 2 Apr. 30 2 .Msy 7 7 3 ‘flay 1 3 May 9 8 2 May 9 3 Decayed p-O-‘-o‘ -- a“ ..—o U0---~-.-u a-nl-ve~u-..i-.‘--_ -—o---- --..--...,- -.- . u- i . - .O..----.r-_“—d.-".~“ . _ - O O . . 5-. O - - we ._ I e . .. _ .. -.~—.—--‘-~-r.~---~‘-“ «a- I - c..... D 04—. .— -27- The lots of mature and immature seed were planted in pots in the greenhouse, November 4, Table I. The dates of the appearance of the first sprout are given. The mature seed.sprouted two to three weeks before the immature seed in the November 4 planting. In the December 4 planting the matured sprouted two to three weeks before the immature seed, Table 2. In the January 4 planting, Table 3, there is very little difference between the time of the appearance of Sprouts in the mature and immature seed. Plantings made February 4, Table 4; March planting, Table 6 and April planting, Table 6, gave the same results as the January 4 planting. The experiment would indicate that the mature seed planted in.November and December sprouted quicker than immature seed, but in January, February, March and April plantings there was no significant differ- ence between the time of appearance of the first sprouts in the mature and immature seed. Photographs were taken of three of the plant- ings, November 4, January 4 and March 4 to show plants produced from mature and from immature seed. -28- In Figure 3 the plants came from mature seed plant- ed November 4, 1926. Figure 4 shows plants grown from immature seed planted November 4, 1926. There was much better growth in most of the plants from mature seed than from the immature seed. Photographs of mature and.immature seed planted January 4, (Figure 5 and 6) show the same contrast of plant growth as in the November 4 planting. There is less contrast between the vine growth in the mature and immature seed of.narch 4 planting (Figure 7 and 8) than in either of the other two dates of planting. bvidence indicates that there is a difference in time of Sprouting of'the mature and immature tubers when planted at the same date early in the storage season, but later in the storage season there is very little difference in the time of appearance of the Sprouts and in the general vigor of the vine growth. Figure III. Plants grown from mature seed that were planted November 4, 1927. Figure IV. Plants grown from immature seed that were planted November 4, 1927. -51- Figure V. Plants grown from mature seed that were planted January 4, 1926. -52- EM «W M .‘Ue ‘ ~‘~‘ .‘\V 5 Figure VI. Plants grown from immature seed planted January 4, -55- Plants grown from mature seed planted “rah ‘. 1927s Figure 711. -54- Figure VIII. Plants grown from immature seed planted March 4, 1927. ' CLNDITILHS LE ”BB SLED AFTER STLhAGE. Representative tubers from each storage were selected and a photograph taken of each lot as they were removed from storage May 10, 1927. All of the storage lots were represented.with the exception of the cold storage 32° F. lot stored within closed containers. The lot stored in tight containers at 32°F. completely decayed due either to the lack of air or to the low temperature or both. The condition.of the seed from each storage can be determined from the following photographs. Figure 11. -56- The three tubers on the left were stored in cold storage 36°F. Three tubers on right stored in closed con- tainer cold storage 36° F. Figure X. -57- Mature and Immature tubers stored in room storage (40-70°F). Three tubers on the left are immature contrasted with three mature tubers at the right. -38- Figure XI. Mature and Immature tubers as they were when removed from pit storage. Three tubers on the left came from mature stock. Immature stock on the right. Figure 111. nature tubers stored in the root cellar at the College. Figure x111. Mature tubers stored in common potato cellar having relatively low temperature during winter and relatively high tem- perature in the spring. Three tubers on the left were stored in the open and the three tubers on the right were stored in a closed container. -41- ..-.._ --.-. e-re’w u «Drug...» Figure XIV. Small tubers at left stored in closed container and contrasted with s tuber stored in open storage at the right. ~42- Eigh temperature storage caused the timers to shrivel considerably, Figure 10. Where the temperature ranged frcm.36° - 400 F. during the winter and increased duriig the Spring, the tubers showed considerable Sprouting, Figure 12. open storage caused the tubers to Sprout more than did the closed containers, Figure 13. When the tubers were stored in cold storage there was very little difference in the sprouting of’the tubers whether stored in the open or closed con- tainers. Low temperature retarded the deveIOpment of Sprouts in all cases. Per cent Stand of Mature and Immature Seed Stored under Various Conditions. Table VIIe Treatment Per Per Per Per cent cent cent cent of stand stand stand weak hills 'June July July 9 15 30 Check average of all 42.9 54.9 55.5 1.6 Boot cellar mature 73.2 96.4 96.4 3.7 R001} Cellar, immature 69e6 96e4 98e2 3e6 Pit Storage, Mature 62.5 98.2 98.2 3.6 Pit Storage, Immature 60.7 94.6 96.4 5.6 Room Storage (40-700F) Mature 14.3 53.9 37.5 57.1 Room Storage (4O-7OOF) Immatwe 5003 50e0 58e9 57e5 Cold Storage 36°F open * Mature 30.2 98.2 98.2 7.2 Cold Storage 36°F open Immature 26.7 96.4 96.4 3.7 Cold Storage 36° F closed, Mature 32.1 98.2 100.0 3.6 Cold Storage 36°F closed,Immature 2.6 94.6 94.6 3.8 Cold Storage 32°F Open Mature ‘ 5.3 50.0 58.9 30.3 Cold Storage 32°F open Immature 7.1 64.2 69.6 23.1 #404- .- -‘-f—- --_—_ e- w . ‘0”. —-I-——.O——~‘- ~——--D: