LI B R.AR.Y OF THE UNIVERSITY LINOIS 50.7 L6b ,.31-48 gric . QN CIRCUUTING CHECK FOR UNBOUND r? RCUI.ATING COPY .CIRCULATING CHECK FOR UNBOUND CIRCULATING COPY UNIVERSITY OF ILLINOIS. Agricultural Experiment Station. URBANA, APRIL, 189?. BULLETIN NO. 40. CONTENTS POTATOES, EXPERIMENTS OF 1892-3-4, WITH A STATE- MENT OF SOME RESULTS OBTAINED AT OTHER STA- TIONS. FUNGUS DISEASES OF THE POTATO. AN EXPERIMENT TO PREVENT SCAB AND LEAF BLIGHT OF THE POTATO. POTATOES, EXPERIMENTS OF 1892-2-4, WITH STATE- MENT OF SOME RESULTS OBTAINED AT OTHER STATIONS. The potato is grown, probably, over a wider area than any other one of our food crops, and forms a staple only less in value for Europe and America than the grain and hay crops. The methods of growing are the results of at least two hundred and fifty years' experience at the hands of intelligent husbandmen, and it would scarcely be expected that the work of the experiment stations, extending over so few years as it has, would make much change. During this short period, how- ever, a great amount of work has been done at the thirty-six different stations in the United States which have worked on potatoes. Many old methods have been proved correct, while important points of progress and suggestions for change have been made. The work of the experiment stations has taken the following general lines : Variety tests. Change of seed from one locality to another. Seed from best and poorest hills. Seed dug early as compared with seed dug late or seed of second crop. 119 120 BULLETIN NO. 40. [April, Size of seed pieces. Part of the potato to be used for seed. Preparation of the soil. Time of planting. Depth of planting. Distance apart of planting. Cultivation; methods and frequency. Fertilizers. Quality and composition. Our own work so far has been chiefly on teats of varieties, of fertilizers and of seed from different sources. Variety Tests. The work of testing the varieties of potatoes was begun in 1892. That year twenty varieties were planted May 6th, and twenty- eight more on the 28th of May. Those planted at the earlier date made a fair average growth and yield, while those planted at the later date were so seriously injured by the drought of summer that no account was taken of them. In fact most varieties planted at the later date produced no marketable potatoes. On the loth to the i2th of April, 1893, potatoes under no different names were planted. Some of these were planted in duplicate plats; in most of these cases the seed for the different plats was obtained from different seedsmen, in order to compare the varieties from various sources. April 13 and 14, 1894, varieties of potatoes were again planted, this time 108 different kinds. A few of those planted in 1893 were omitted, while a few new ones were added to the list. Each season the planting was begun as soon as the ground was in first rate condition for planting and there was promise of sufficiently settled weather to allow all the planting to be done at once. The plats were of one row each, varying in length from four to six rods. The rows were 3^ ft. apart. These were furrowed out to a depth of 4 inches as nearly as could be done. The potatoes, usually cut to two eyes, were then planted in drills as nearly as possible one foot apart. The ground was kept clean by frequent, nearly level, shallow cultivation. The seasons each year were exceptionally dry at a time when the potatoes needed rain to mature them properly and they were also more or less attacked by a form of leaf blight, causing the plants to die before the tubers were matured. The early varieties seem to start in the spring with more vigor than the late ones and the leaf blight has so far ap- peared to be worst on the varieties which are making the rankest growth at the time the attack begins. In the following table the yields of the various varieties are given for the years 1892, 1893, and 1894. In 1892 there were only two vari- i8 95 .] POTATO EXPERIMENTS, 1892-3-4. 121 eties planted in more than one plat. These plats, however, were only a short distance apart and the soil so far as could be judged was quite uniform. In 1893 more than one plat was planted of 37 varieties. In all cases where more plats than one of a variety were planted the plats were side by side, and being of a single row each there could be very little difference in the soil. The seed, however, for each plat was from a different source and the difference in yields is sometimes remarkable. This will be discussed under change of seed. In 1894 where there are two plats they were planted in different parts of the field. In cases where there are four plats two of them were planted in one place and two in another, so that for this year much of the variation may be attributed to difference in soil, since the seed for all the varieties except Acme, Columbus and new banner was from home grown seed. The following table gives the yield of the different varieties tested for the years 1892 to 1894. In judging of yields it will be remem- bered that the soil here is a rich, black, prairie soil, which has not gen- erally been considered a good potato soil. YIELDS OF POTATOES, 1892, 1893, 1894. Variety. Yield in bu. per acre, 1894. Yield in bu. per acre, 1893. Yield in bu. per acre, 1892. Total. Mer- chant- able. Total. Mer- chant- able. Total. Mer- chant- able. Acme 59-5 42 "3-5 78.5 126 72 91-5 46.5 27.5 95-5 66 99 58 67-5 Alexander's No., i 54-5 37-5 Alexander's prolific 53 50.5 23 54 31-5 83 43-5 35-5 15.5 39-5 22.5 65-5 1 60 143.5 American giant 103.5 92-5 99-5 103.5 9i 61 57 74 78.5 64.5 121.5 126 104.5 112.5 114 88.5 80.5 82.5 9i 103.5 82 109.5 70 84.5 70 72.5 64-5 42 42 55-5 45 32 88.5 87 73 80.5 79-5 54-5 51-5 53 80.5 87 66 94 44 43-5 Arizona 70 45 34 5 55-5 31-5 23-5 103.5 89 Badger state 193-5 170 Badger state peachblow .... 21.5 ii Baker's seedling 76.5 57 Barstow . ... ... 49 39-5 Beauty of Hebron 72 46.5 50 32.5 165.5 136 Boley's northern spy . . 78 58 63 48 Brownell's 31 66.5 40 122 BULLETIN NO. 40. YIELD OF POTATOES, 1892, 1893, 1894 Continued. [April, Variety. Yield in bu. per acre, 1894. Yield in bu. per acre, 1893. Yield in bu. per acre, 1892. Total. Mer- chant- able. Total. Mer- chant- able. Total. Mer- chant- able. Brownell's winner 105 148 128.5 170.5 152.5 171 105-5 101 120.5 151 125-5 128 164 107 87 66.5 88.5 82 70 71-5 124.5 160.5 78 85 90 86 89 99-5 64.5 78 114 76 66.5 70 80.5 119 55-5 70.5 132 150 103 155 89.5 1 08 81 108.5 95 128.5 112.5 122 73 70 94 H5.5 99-5 93 135 95 61 51-5 53 44 46.5 41-5 83.5 117.5 67.5 80 58.5 62.5 65 68.5 45 64 98 48 17 22 58.5 99 42.5 58.5 75-5 1 06 78 128.5 72 9i 36.5 48.5 26 34 Burbanks 45-5 34-5 Burpee's extra early 46 29-5 Burpee's superior 28 36.5 21 29 135 114 Carman Cayuga . . 22.5 14.5 Chas. Downing 49 36.5 25.5 19.5 Cheeseman 66 41 Chicago Market 58 48.5 Clark's No. i 93-5 68.5 Columbus Crown jewel . 58.5 73 36 52 Cow horn 24 6 Crane's Juneating 67 48.5 Cream City 32.5 2l' Dandy 82.5 52.5 48 72.5 63 53 36.5 67 55-5 24 64 40.5 33-5 60.5 54 46 30.5 64.5 48 18 Dakota red Delaware 119 "5 94 IOO Dreer's standard 170.5 99 120.5 80.5 95-5 86 112.5 60.5 77 148 74 98 58.5 77 50 9i 42.5 66 Early albino 73 52.5 189 149 Early Essex 44 26.6 Early Illinois 40 3i-5 Early market 61.5 43 47 33-5 i8 95 .] POTATO EXPERIMENTS, 1892-3-4. 123 YIELDS OF POTATOES, 1892, 1893, 1894 Continued. Variety. Yield in bu. per acre, 1894. Yield in bu. per acre, 1893. Yield in ba. per acre, 1892. Total. Mer- chant- able. Total. Mer- chant- able. Total. Mer- chant- able. Early Oxford 91.5 120.5 53 79-5 36.5 23 81 7i Early Ohio 2OI .5 165 Early Puritan 57 "5-5 74 138 84-5 121.5 77 169.5 61 38 93 38.5 115.5 59-5 93 52 133-5 40 29-5 31-5 19-5 22 19.5 10 Early sunrise Early Walton 23 12 17-5 19-5 15 68.5 32-5 45 12 8 10 52.5 28 35-5 216 186* Early Wisconsin Empire State Everett .... 4 63-5 "3-5 IOI 131 68.5 75-5 72.5 56 70 162.5 "3-5 157-5 143 105.5 100.5 35-5 86 78.5 85 37 48 45 27-5 43-5 139 8i-5 "9-5 "5-5 70.5 66 38 3i Freeman 30.5 34 15.5 17 Garfield 28.5 18 Gen. McLellan 64 89.5 57-5 78.5 Golden beauty 48 38.5 Howe's premium 4i 35-5 57-5 105 35 26.5 45-5 84 Grange 157-5 188.4 70 75-5 82.5 112.5 100.5 99 81 80.5 88.5 78 95-5 139-5 38.5 37 95-5 96.5 37 67.5 58.5 64-5 105-5 124.5 13 28 46.5 81 98 75-5 46.5 40 63-5 68.5 78.5 105.5 21.5 29-5 64.5 67.5 25 53-5 38 5 43-5 Harbinger . . 34 15 Kings Co. mammoth 72.5 61.5 Koshkonong 59-5 48.5 Lee's favorite 1 83 50.5 48.5 68.5 39 44 I7I.5 146.5 Manitoba rose Martin's seedling. .. 79-5 68 M3-5 "3-5 Maggie Murphy 52-5 43-5 Monroe 40 29 Monroe Co. pride 32 22.5 Monroe Co. pride 27 17 15-5 77-5 21 10-5 10 60.5 Nevada .... 119 i3 5 87.5 93 124 BULLETIN NO. 40. [April, YIELD OF POTATOES, 1892 1893, 1894 Continued., Variety. Yield in bu. per acre, 1894. Yield in bu. per acre, 1893. Yield in bu. per acre, 1892. Total. Mer- chant- able. Total. Mer- chant- able. Total. Mer- chant- able. New queen 78.5 "5 66.5 101 83.5 5i.5 58.5 54 93 74 103 56 83.5 51-5 79-5 52 34-5 45 30.5 67-5 43-5 74 32 27 Nott's victor.. 84.5 65.5 New banner Ohio junior 43-5 25-5 43-5 34 20 28.5 156 135-5 Paris rose 122.5 116. Pearl of Savoy 5i 26 63 54-5 39-5 2O.5 39-5 49-5 163.5 108 5 136.5 93- People's.. . 82.5 68.5 69 98.5 64.5 17.5 95-5 99-5 68.5 83.5 51-5 81 109.5 106 69 9i.5 70.5 in. 5 122 62 66 68.5 96.5 no 70 68.5 66.5 "3-5 1 06 78 75-5 99 56 73 57-5 79-5 129.5 137-5 66 78.5 38.5 29 53 36 54-5 40 40 74-5 35-5 42.5 78.5 77 40 58.5 35 5 67-5 64-5 78.5 55-5 78 42 77 9i-5 34-5 47-5 . 38.5 70 70-5 42.5 42.5 4 1 82 77 55-5 53 66 35-5 38.5 16 21 107.5 II0.5 53 54 6 none 44 26 Perfect gem 52-5 38 Polaris 5i.5 64 62 37-5 45 52 Pootatuck 56.5 44 Potentate 65.5 60 Prince Edward's Island rose 5i 77-5 54 42.5 64 48 Pride of the field Pride of the west .... 70 60.5 Queen of the valley 49 4i 40 29 Quinnipiac 68 5i 24 36.5 25-5 45 43 57 40.5 12 23 19-5 34-5 34 Reed's 86 M3 120. Rural New Yorker No 2 130 114. Rogers seedling 34 15.5 Rough diamond ii-5 none Rural blush 37-5 29 35-5 28 Red lady finger 19.5 4 Red Ohio 1895-] POTATO EXPERIMENTS, 1892-3-4. 125 YIELD OF POTATOES, 1892, 1893, 1894 Continued. Variety. Yield in bu. per acre, 1894. Yield in bu. per acre, 1893. Yield in bu. per acre, 1892. Total, Mer- chant- able. Total. Mer- chant- able. Total. Mer- chant- able. Snowflake 104.5 72.5 9i.5 70.5 107 78.5 58 56 71-5 70.5 89 46.5 70 48 86.5 61 38.5 35-5 48 43-5 29 17 24 ii 119 IOI. State of Maine 57 46 Sunlit star 37-5 32 Signal 57-5 37 Six weeks market 67 24 58 23 59 20 46 13.5 Summit 88.5 93 56 64-5 118 130' 7i.5 78 70 66.5 9i 62.5 71-5 70 74 52 62.5 98.5 46.5 77 82 157-5 126 101 122 91-5 86 76.5 54 54 25-5 27.5 89 97 39-5 5 47-5 45 5 40 42.5 44 39-5 29 5 69 28 50 59-5 121.5 82 66.5 IOI 62.5 58.5 50 Shattuck s kidney Spaulding 41.5 35 Theoborn 28 31-5 21 22.5 Tomnock 34 2O.5 Vick's extra early 18.5 20.5 4-5 8-5 38 6.5 17 4 6 18 Vaughan 204 186. Van Ornam 12 10 12 White flour 7-5 9-5 White orange 13.5 10. White star 10 7-5 8 8.5 5-5 17 3 5 5 6 3 M White lily White seedling Winslow 36 64.5 57 74-5 73 4i 38.5 21 45 41 5 49 28 24 Wisconsin beauty World's Fair 22 14-5 Stray beauty I6. 5 26 12 '7-5 Triumph The potato varies remarkably. The reply made by one of our local potato growers when asked about some new varieties he was testing does not seem to be much too strong: " You can't tell anything about a potato the first year." Perhaps it might be well to say that results for the second and third year make the conclusion only so much less uncertain. 126 BULLETIN NO. 40. [Apri,, Descriptions were made of the varieties as grown in 1892, 1893, and 1894. The later descriptions were made without consulting the earlier, and it is found that they often disagree in important characters. The conditions of season seem to make a difference, not in yield alone, but in appearance, form, and quality of the tubers as well. Tubers of the same variety have seemed to differ widely, too, in the same season. This is especially noticeable in the character of the flesh of the potato, which will often vary in color from white to yellowish white, in grain from fine to coarse, and in texture from tender and crisp to tough or hard, becoming harsh to the touch. Not unfrequently tubers will be found in a variety that have a decidedly sweetish taste. In many cases the individual tubers of a variety will be found to differ more from each other than two varieties will when taken as a whole. Testing varieties has received more attention at the hands of station workers than any other phase of potato culture, and the sum of their results seems to be that the standard varieties are at least the safest for the general planter. Occasionally a new kind comes out that in one or more respects is superior to some of the old ones, but it scarcely seems possible to find all the virtues combined in one variety to such an extent that it is without question the potato. Perhaps the most extensive experiments with varieties have been carried on at the following stations: Indiana, through four seasons; Michigan, six seasons; Wisconsin, six seasons; Kentucky, four seasons; Ohio, seven seasons, and Missouri, two seasons. Summing up all the results from the above stations, the following named varieties are among the most productive sorts: Alexander's prolific, Early harvest, Beauty of Hebron, Early Ohio, Burbank, Howe's premium, Charter oak, New queen, Clark's No. i, Pearl of Savoy, Dakota red, Rural New Yorker No. 2, Dictator, Rural blush, Early sunrise, Summit, Early king, Thorburn, Empire state, White elephant. Early Oxford, In looking over the station reports it is found that there are no two agreeing in their estimates as to which is best, and usually the same station does not agree with itself two years together. The potato seems to be so variable and so sensitive to the conditions under which it is grown that about the only recommendation which it is safe to make would be to adhere to the standard varieties, at least for the main crop. POTATO EXPERIMENTS, 1892-3-4. Comparison of Seed from Different Sources. There is a widespread belief among farmers that it is best to change, occasionally, seed of all kinds of crops. There is not much doubt but that in many cases it is better to change seed, but it must have its limitations. Along with our test of varieties some comparison has been made of potatoes from different sources for seed, but it will not do to interpret results too closely. The following table will give the varieties compared and the source of seed in each case: COMPARISON OF YIELDS FROM SEED FROM DIFFERENT SOURCES. Variety. Old's seed. Home seed. Variety. Vaugh- an's seed Home seed. American giant 23 31.5 Alexander's prolific. . .. 50.5 c j Charles Downing 49 36.5 Arizona 7o 45 Crown jewel 73 58.5 Beauty of Hebron, . . . 72 46 5 Dandy 52.5 82. * Burpee's superior . . 28 ^6 5 Early market 43- 61.5 Early Ohio 31 1 1 . 5 Early Puritan 31 .5 29.5 Early white prize 17.5 iq <; Howe's premium 4 1 57-5 [Empire state 68.5 32 5 26 ;i i Freeman 155 17 Polaris 51.5 62 Ohio junior 25.5 43. c Queen of the valley. . . . 49 41 Reed's 86 36.5 24 Signal 29 5 57 5 Rural New Yorker 4 3 25 1 Summit 24 58 Snowflake 2Q 17 Thorburn 28 31 . c Vaughan 4 5 8 Variety. Howe's seed. Home seed. Variety. Old's seed. Howe's seed. American giant 54 31 .e American giant . . 27 54 Boley's N. spy 58 78 Dakota red 33-5 60. 5 Brownell's winner 36.5 48.5 Delaware 53 63 Howe's premium 35 -5 57-5 General McLellan . . . 64 89 5 Early Ohio 29. 5 11.5 Howe's premium 41 3c e Pearl of Savoy 63 51 Pearl of Savoy. . . 26 63 Polaris 64 62 Polaris 51 . 5 64 Prince Edward's Island rose 51 77-5 White flour IO 12 Quinnioiac SI 68 Rural New Yorker .... 45 25 5 Variety. Howe's DOI Vaugh- Old's Vaugh- Variety. seed. an's seed Delaware 63 36.5 Porlw Ohin Delaware. . 53 36. 5 Rural New Yorker.. 2 9 -5 45 3 1 43 In five cases out of ten that are comparable home grown seed yielded more than seed from Howe, and the average of the ten com- parisons is in favor of the home grown seed in the proportion 100 to 95. In ten cases out of thirteen that are comparable home grown seed yielded more than seed of the same variety from O!d=, and the average of the thirteen comparisons is in favor of home grown seed in the pro- portion of 100 to 79. In six cases out of thirteen in which home grown seed can be com- pared with seed from Vaughan, the home grown seed has yielded the 128 BULLETIN NO. 40. most, but the average of the thirteen comparisons is in favor of Vaughan's seed in the proportion of 100 to 86. In seven cases out of eight than can be compared seed from Howe produced more than seed of the same variety from Olds, and the average of the eight comparisons is in favor of Howe in the proportion of 100 to 70. In the one case in which the same variety was grown from seed obtained of both Olds and Vaughan the comparison is as 100 to 69 in favor of Olds. In three cases in which the same varieties from Howe and Vaughan were planted seed from Howe yielded more than that from Vaughan in two cases, and the average of the three comparisons is in favor of Howe in the proportion of 100 to 80. As a result of these comparisons we have home grown seed yield- ing more, on an average, than seed from either Howe or Olds, but less than seed from Vaughan, while seed from Vaughan has yielded de- cidedly less where it could be compared than seed from either Olds or Howe. In four varieties the same seed was from Olds, Howe, and home grown. In one of the cases home grown seed stood at the head of the list and in the other three cases it was second. In three cases Howe's seed stands at the head of the list and in the other it is at the foot. In one case Olds' seed stands second in the list and in the other three cases it is at the foot. Seed from each plat of fifteen of these varieties which have been compared in this way for 1893 was saved and again planted side by side in 1894 and in twelve cases out of the fifteen seed from the plat giv- ing the best yield in 1893 also gave the best yield in 1894. In plats arranged as these were, only a single row each, and only three and one-half feet apart very little allowance can be made for difference in soil. Perhaps the only conclusion that can be drawn from the comparisons is that some character or condition of the seed, which we do not yet understand, must make a large difference in crop. But it will not do to say that seed from one place is necessarily superior to seed from another. In general the northern states seem better adapted to the growth of the potato than the southern; but there are local modifying causes, such as the character of the soil and season, insects, fungus diseases and the growers' general care of his crop. I believe it would be possible for the potato growers of this state so to manage that change of seed would be of but little advantage. In fact the average result of experi- ments in this line leaves it an open question as to whether there is or is not a benefit from changing seed so as to have new seed of the same variety but from a new source. Perhaps the most extensive work in studying the effects of change of seed has been done at the Vermont and Maryland stations. Eight 1895-] POTATO EXPERIMENTS 1892-3-4. 129 varieties of potatoes were obtained by the Vermont Station and grown by them one year. Seed from these was then sent to Maryland, and the same eight varieties were then grown one year at each place. Seed was then exchanged, Vermont sending seed to Maryland, and Mary- land sending seed to Vermont. As a result we have in 1889, the fol- lowing as an average of the eight varieties: In Vermont, potatoes from Vermont grown seed yielded in Ib. In Vermont, potatoes from Maryland grown seed yielded 73 " In Maryland, potatoes from Maryland grown seed yielded 54 " In Maryland, potatoes from Vermont grown seed yielded 62 " But this result is not uniform, for in four cases out of the eight in Vermont the seed from Maryland gave the best yield and in Maryland their home grown seed gave the best yield in five cases out of the eight, though the average was still in favor of the Vermont seed. The Maryland Station also compared Vermont seed with Maryland seed in 1890 and '189 1, the results in both years being in favor of the Vermont seed; in 1890 Vermont seed yielded at the rate of 179 bushels per acre and Maryland seed at the rate of 97. 15 bushels per acre; in 1891 Ver- mont seed yielded at the rate of 125.5 bushels per acre, and Maryland seed at the rate of 88.5 bushels. In 1892 seed from Maine was com- pared with Maryland grown seed. The result was 95.5 bushels per acre from the home grown seed, and 72.6 bushels ->er acre from the Maine seed. Georgia Experiment Station, in bulletin No. 8, 1890, says "home grown seed gave slightly higher yields than that imported from the North." Louisiana Experiment Station, bulletin No. 4 (new series), 1890, says "western grown potatoes are as good for seed as those grown in the East. Home grown seed is as good as, if not superior to, either." Missouri reports a comparison of home grown and northern grown seed in 1890, with twenty-seven varieties and the result as a whole was in favor of the home grown seed in the proportion of 100 to 98. In New York a single trial did not favor the practice of changing seed. In considering these statements in regard to results of change of seed as found in this way, it must be remembered that at the sta- tions potatoes are grown under better conditions than are generally found in farm practice. Seed from Best or Poorest Hills. No one has dug many potatoes without noticing the difference in individual hills. One will yield a few very large and a few small tubers, another will be uniform in size and all large, and still another will be nearly all small. Some experiments have been made to see if these characters could be perpetuated. Hills containing all large and others containing all small potatoes have been saved and planted side 130 BULLETIN NO. 40. by side. This line of work has been carried on at three different sta- tions, and though it has not gone far enough to prove conclusively that there is an advantage in selecting the best hills, the results point in that direction. Trials with eleven varieties at the Geneva, New York, Station, re- sulted in favor of seed that had been selected from the best hills. In another trial at the same Station with 116 varieties in garden tests the largest yields were obtained in 69 cases from the largest seed that could be selected from the best hills of the previous years' crop, while in 38 cases the reverse was true. Digging Potatoes late and early for seed: Second crop. The Kansas Station made comparisons for two seasons of the value for seed of potatoes dug early, of those dug late, and of those grown as a second crop. (By second crop is meant that the potatoes were dug early and planted at once, making a second crop the same season). They conclude, first, that there is nothing gained in earliness by using second crop seed; second, that there is a positive gain in amount of product, as well as size of tubers, over that of first crop seed grown in the same locality; third, that firm, well kept, unsprouted seed is better than that which is sprouted and shriveled, giving a heavier product of better size and quality. Growing a second croo is not recommended, except in localities where the seasons are long. The size of seed pieces to plant. The size of seed pieces to be planted has received more attention than any other phase, except the test of varieties. Twenty stations have carried on large numbers of experiments, and the general conclu- sion reached is that the larger the seed pieces the greater the yield. This is so decidedly true that in the average of trials made, good-sized whole potatoes have yielded nearly twice as much as potatoes cut to one eye, and there has been nearly a uniform gradation in the crop as the size of seed passed from good-sized whole potatoes through halves, quarters, three-eye pieces, two-eye pieces, to one-eye pieces, and the result has fallen still lower when peelings have been planted for com- parison. As a specimen of the reports made, this from Ohio is given. It is an average of two years' results. One eye pieces yielded 1 15 bushels per acre. Two-eye pieces " 180 " " " Half potatoes " 226 " " Whole potatoes " 255 " " " The following conclusions are deduced from all of the work done at the Ohio station on the subject of cutting seed: " The marketable product increases as the size of the cutting is increased, but does not follow the same ratio as the total product, the rate of gain being less." 1895-] POTATO EXPERIMENTS, 1892-3-4. IJI '' The increase is found in both the large and small potatoes, the greater portion being in the latter." " A crop grown from whole potatoes matures at an earlier date than from small cuttings." " Small cuttings require soil that is more highly enriched and thoroughly prepared than large cuttings and whole potatoes in order to secure a good stand and to produce a profitable crop." " The question of relative profit as between the use of small cut- tings and whole potatoes depends upon the cost of seed potatoes, the date at which the crop is to be harvested and sold, and the condition of the soil at planting time." " In ordinary practice it will usually be found that neither extreme as to quantity of seed used will be profitable. The safest plan is to use large, well-matured, healthy potatoes, and cut to two and three eyes." . . In contrast with the results which are so overwhelmingly in favor of heavy seeding may be mentioned the following exceptions: In a trial at the New York Station there was practically no difference in yield between cuttings and whole potatoes. In Oregon one-eye pieces yielded more than two or three eye pieces or whole potatoes. Two experiments out of three at the West Virginia Station favored one- eye pieces, and in one trial the yield was 30 per cent, greater with single- eye pieces than with whole tubers. Mr. Terry, of Ohio, says he never uses larger than one-eye pieces for planting, and yet his average yield for a number of years has been nearly two hundred and fifty bushels per acre, while the average for the state is below seventy-five bushels. He says he cannot afford either the labor of handling more seed, or to put more money into seed ; and while his fields look poorer early in the season than those of his neighbors, they soon improve and eventually yield more. He does not depend for his crop on the amount of seed planted, but on the thorough preparation, cultivation and fertilization of his soil. Before deciding on the amount of seed to plant, we must consider the cost of seed potatoes as compared with those for the general mar- ket. The amount of seed needed for an acre, if whole large tubers were planted, would be from 30 to 40 bushels, while for single eye- pieces from 3 to 4 bushels is sufficient. The reasons for the larger yield from the larger seed are: A greater number of plants are formed; these, having a greater proportional amount of seed to each one, make a more rapid, vigorous growth at first and ripen earlier, and at least partly escape the summer drought and the effects of leaf blight. An early drought followed by favorable weather may occasionally give a larger yield from small seed. The difference in time of maturity of potatoes from large whole potatoes and single eye pieces is variously estimated at from one to two weeks, and where potatoes are wanted for early market it may pay to 132 BULLETIN NO. 40. [April, plant the extra amount, but for the general field crop the common practice of cutting to two eyes, except where the eyes are very close together, will be found the best. This, however, would not seem to hold where exceptional fertilizing and care are given. Experiments 'with Different Parts of the Potato for Seed. There has been, for a long time, more or less theorizing as to whether it is best to use the stem end, the middle, or the seed end of the potato for planting. As a result of a large amount of work done at ten of our experiment stations, the conclusion is reached that it makes no difference. As an illustration of the contradictory results, the following may be given: A summary of trials for three years at the Michigan station shows the greatest yield of marketable tubers from seed end, next largest yield from stem end; while at the New York Station a large number of trials indicate that the central portion of the potato is best for seed. In Utah the results for two years were in favor of planting the stem end; In Wisconsin the removal of the seed end from the potato showed no advantage in yield. In Indiana (Bull. 34, 1891) the seed end of the potatoes yielded 74 bushels per acre, middles, 107 bushels per acre, and stem ends 94 bushels per acre. In Colorado (Bull. 4, 1888) seed ends of potatoes yielded 344 bushels per acre, while stem ends yielded 290 bushels per acre. In this way the results from the different stations neutralize each other. Time of Planting. The question of time of planting in its relation to yield has scarcely been considered in the way of direct experiment. There seems no rea- son to doubt, however, that with rare exceptions the earlier the planting is done the better will be the crop. The late planting is too apt to be cut off by hot, dry weather and the leaf blight. Late varieties, too, have been almost driven out of the field on account of the leaf blight and the uncertainty of having seasonable weather for growing and ma- turing the crop. Depth of Planting. Depth of planting potatoes has been made a subject of study at five experiment stations. The results have been somewhat contradictory but with the greater number of trials turning out in favor of compara- tively shallow planting. In Michigan the results for 1890 and 1891 were in favor of planting one or two inches deep rather than three, four or five, while in 1893 the planting five inches deep gave the best results. From Utah the statement comes that " the depth of planting did not materially affect the total yield of potatoes;" but "potatoes planted near the surface contained 23.1 per cent, more starch than those planted 1895-] POTATO EXPERIMENTS, 1892-3-4. 133 deeper." In the greater number of trials the best results have come from planting two to three inches deep. Distance Apart for Planting Potatoes. This has been made a subject of study in eight states, and the average of the results goes to prove the common practice among far- mers to be correct. Hills have seldom given as good yields as drills. In drilling potatoes Michigan makes a distinction between planting whole potatoes and pieces, and recommends for single eyes twelve to fifteen inches apart, for half potatoes, two feet apart, and for whole potatoes two and one-half feet apart. Ohio says results show that rows should be from two and one-half to three feet apart and the hills one foot. This is supposing one or two eye pieces are used for seed. In thirty-two trials of hill as compared to drill planting in Michigan the results were in favor of drills. The New York Experiment Station, at Geneva, reports in favor of drill planting. Wisconsin has found no material difference between hills and drills. Cultivation. In a large number of experiments at twelve different stations, com- parisons have been made of methods of cultivating potatoes. Seasons vary so much that the results of different methods are continually con-- tradicting each other. One season potatoes mulched will yield two or three times as much as those grown in the ordinary way, and the next year the results will be almost the opposite. In trials where direct com- parisons were made, results from Alabama, Kansas, and Utah favor flat , while Indiana favors ridge cultivation. Maryland, New York and Ohio report practically no difference in yield between flat and ridge culture. Vermont reports that in one season's trial mulching when four inches high, gave better results than ridging. Results obtained at the stations in Colorado, Indiana, Michigan, and New York are against mulching. The general tendency seems to be toward thorough prepa- ration of soil, and level culture. Comparisons of deep and shallow cultivation have been made at the Michigan and Utah stations, with very different results. In forty- five trials at the Michigan station, the yield of marketable tubers was in forty cases in favor of deep culture, while in Utah shallow culture gave a greater yield than deep. Results are so conflicting that no conclusions can as yet be drawn. Commercial Fertilizers on Potatoes. Beginning with 1893 some work has been done in testing the effects of commercial fertilizers on the potato. Plats two rods square were laid out with a space of eight feet between them in the direction in which plowing and cultivation was done. In the other direction no '34 BULLETIN NO. 40. [AprtZ, space was left. The experience at this Station with commercial fertil- izers on other crops is that they are of no appreciable benefit and the result with potatoes has been the same. While the yields of the plats varies greatly, there is no variation that can, with certainty, be attributed to the use of the fertilizers. But the results here are not to be taken as conclusive for all parts of the state. Soils of different places have dif- ferent requirements and must have different treatment. There is no way of determining in advance what fertilizing element or elements will and what will not benefit a crop. The only way to find out is by trying. NORTH. No 4 . No. 3. No. 2. No. i. Sulphate of pot- ash, 200. Nothing. Acid phosphate, 360. Nitrate of soda, 200. No. 8. No. 7. No. 6. No. 5. Nitrate of soda, 200. Acid phos- phate, 360. S u 1 - phate of potash, Acid phosphate, 360. Sulphate of potash, 200. Nitrate of soda, 200. Sulphate o f potash, 200. Nitrate of soda, 200. Acid p h o s - phate, 360. 200. No. 12. No. ii. No. 10. No. 9. Lime, 2,000. Acid phosphate, 360. Lime, 2,000. Nothing. Hardwood ashes, 2,000. No. 16. No. 15. No. 14. No. 13. Mapes tree and vine fertilizer, i , ooo. Mapes special po- tato fertilizer, 1,000. Hardwood ashes, 2,000. Nitrate of Lime, 2,000. Ni- trate of soda, 200. soda, 200. Acid phosphate, 360. Sulphate of potash, Acid phosphate, 360. Sulphate of potash, 200. 200. No. 20. No. 19. No. 18. No. 17. Nothing. Nothing. Nothing. Nothing. I895-] POTATO EXPERIMENTS, 1892-3-4. '35 The diagram on the opposite page shows the arrangement of plats and the number of pounds of fertilizers per acre applied to each. Nos. 15 and 1 6 had fertilizers in 1894 On ^y5 on ^ e other fertilized plats fertilizers were applied both in 1893 and 1894. At the Kentucky Experiment Station (Lexington) potash, either in the form of muriate or sulphate has been used profitably while neither nitrate nor phosphate has made very appreciable increase in the yield. At the Michigan Experiment Station (Lansing) wood ashes gave better results than any of the commercial fertilizers, while barnyard manure was found better still. It is entirely probable that in other parts of this state valuable results could be had from the use of some of the commercial fertilizers. Most of the experiment stations in other states have found benefit in applying a commercial fertilizer in some form ; but usually it is not necessary to use a complete fertilizer, because it is not usual for all the three principal elements of fertility to be lack- ing. Not unfrequently the application of nitrogen, or potash, or phosphorus alone in some form, gives nearly as good results as the application of all of them, and at a decidedly less cost. TABLE GIVING YIELDS OF POTATOES ON FERTILIZED PLATS AND CHECK PLATS FOR -1893 AND 1894. 2 sT Fertilizers. S H S a o "> cr 5T C M w< oo>O M. 5 n . m in t^ >l S M N M M O m w ro oo m 4 MM IN M O * "rt C/) t^ oo m m m ft t^ t^ m w O fl OO M -T O m CTivO N 00 PO vo oo vo lumber. Medium. r^ m N m co r^ t^ >f m N S 1 * m PO m fo PJ O TI- m o a\ o ^- N T3 a a > J XI >Xi , rt J + 1 1 M mvo M + 1 CTi -f t^ m PO ^ 00 PO P) ++ PO PO PO * M PO T3 6 V 14 (14 oo N in M O 00 M M OO Ov O m m M M M M Tt- 00 , XI X) rt u C/5 m m in m f- oo M O vo m N O O m vo m PO C* t^ O * M TJ- (A 4) a 4 5 m t- O m o (7> M VO OO in O M * * CTi m P w MOO vo m M POVO PO M P< PI a 3 H DC 3 OJ V u u< m >n c^ O> O 1-1 N >n m PI N M CO O N m M in m PI o -i- * PO ^ m m t^oo MM * m . M M m MM T3 "o a Xj J5 _ec ' >, XI X) rt o- C/D in . in r^ N m m f^ t^- PO M m in M t>- ^ 1 i Alexander's prolific. Quinnipiac *Howe's premium.. Alexander's prolific. Quinnipiac Howe's premium. . . Alexander's prolific. Quinnipiac Howe's premium... Alexander's prolific. Quinnipiac *Howe's premium. . Alexander's prolific. Quinnipiac Howe's premium. . . . 0) B a ^ a u Treated seed with corrosive sublimate. Treated seed with cor. sub. Sprayed with Bordeaux mixture. Treated seed with cor. sub. Sprayed with Bordeaux mix. combined with Paris green. Sprayed with Bordeaux mixture. No treatment. J3 Z T3 PO 60 .! 3 S < XI 60 E 3 3 Q fc p 3 i