UNIVERSITY OF B.C. LIBRARY DUPL 3 9424 05045 410 4 STORAGE LILM PROCESS liiiJ-CSE Lpl-DlbA U.B.C. LIBRARY THE LIBRARY THE UNIVERSITY OF BRITISH COLUMBIA Digitized by tine Internet Arciiive in 2010 witii funding from University of British Columbia Library http://www.archive.org/details/potatopracticalOOfras ci.L-. U8RARV THE POTAT0 A PRACTICAL TREATISE ON THE POTATO, ITS CHARACTERISTICS, PLANTING, CUL- TIVATION, HARVESTING, STORING, MARKETING, INSECTS, AND DISEASES AND THEIR REMEDIES, ETC., ETC. SAMUEL FRASER Assistant Agtonomist, Cornell University ILLUSTRATED NEW YORK ORANGE JUDD COMPANY 1915 COPYKIOBT, 1905 B¥ ORANGE JUDD COMPANY \ Piinied in U.S. A. To %cmtB ^cott (Borbcn WHOSE LIFE AND WORK ARE AN INSPIRATION TO MANY PREFACE The literature issued on the subjedl of potatoes during the past three hundred years would form a large library, many works having been published in the United States, the United Kingdom, France, Germany, and other countries. It is safe to say that no plant has aroused a deeper interest than ' ' the noble tuber. ' ' Its very existence to-day is largely due to the efforts of enthusiasts. Several of the older writers were keen observers and acquainted intimately with the history and character of the potato, and modern authors in- clude the names of men who are eminent in the scientific world. The vast amount of research and demonstration carried out by the experiment stations of this country during the past ten years, and the fadt that every station has done something in this line, show the breadth of the subjecft and furnish material hith- erto unobtainable. The excellent research work now being carried on in Europe, especially in France, Ger- many, etc., and more recently established in Ireland, indicates a demand for more information about this crop. We feel that the "science of agriculture" is a reality ; that, like every past generation, we are on the eve of great discoveries; that something of the laws governing plant nutrition and growth will shortly be revealed, that we may be able to prevent rather than cure the troubles which assail our plants. To be of Viii PREFACE any use, scientific research must be rigidly accurate in its observation and merciless to fallacy in logic. Once a principle is proven it is of no use unless applied, and the man to apply it is the farmer. At the present time it behooves us to divest our- selves of prejudice, whether of tradition or custom, which might tend to warp our judgment and treat as debatable assumptions which long-established associa- tion have made shameful to doubt, but which, undis- turbed, w^ould make the discovery of truth impossible. To-day theories are no longer revered because our fathers l^elieved in them. The search-light of all- prying Science illuminates the whole field of agricul- ture, and has led men to doubt and call in question even truth itself, in order that they might expose those things which are not true. It is by this means alone, by this attitude of questioning all statements and theories, both the truth and the untruth alike, that we can form a just estimate of what is true. That w^hich cannot stand the fire may rightly be esteemed dross. In this book the endeavor has been to colledt many scattered fadls from many sources, and present these — along with experience derived by growing potatoes for several years, commercially and experimentally, in two continents — in the hope that these data will be of value to the reader. Samuel Fraser. CoRNELi, University, Ithaca, N. Y., 1905 No/f.— With the exception of Figs. 26, 27, 28, 29, 30, 31, 43, and 44, which were kindly loaned by the makers of these implements, and those in which credit is given in the text, all illustrations have been prepared by the Author. CONTENTS CHAPTER I PAOBS History and Botany 1-7 CHAPTER II Some Conditions Influencing Growth AND Development 8-16 Influence of Light on Yield, 8; Amount of Mois- ture, 8; Respiration, 9; Influence of Tempera- ture on Respiration, 9; Influence of Temperature on Growth, 10; Potato Roots, 10; Influence of Depth of Planting on Roots, 15; Blossoming, Tuber Formation, and Hilling, 16. CHAPTER III Soils 17-25 Best Soils, and Reasons why Certain Soils are Better than Others, 17; Influence of Soil on Different Varieties, 19; Subsoiling, 20; Prepara- tion of the Soil, 21; Surface-fitting Tools, 23. CHAPTER IV Rotation 26-29 CHAPTER V Manuring and Fertilizing 30-50 Object, 30; Influence of Nitrogen, 31 ; Influence of Potash, 32; Sources of Potash, 33; Influence of Phosphoric Acid, 34; Influence of Calcium, 35; Barn Manure, 36; Function of Fertilizers, 39; Purchasing and Applying Fertilizers, 42; Value, 43; Unit Value, 44, Purchasing, 44; Valuing Barn Manure, 44; Mixing Fertilizers, 46; Ap- plying Fertilizers, 48; Water Requirement, 48. X CONTENTS CHAPTER Vi PAGES Considerations of Sekd 51-69 Source of Seed, 51; Management of Seed Previ- ous to Planting, 53; Sprouting Potatoes, 54; Sprouting Trays, 60; Whole vs. Cut Sets, 60; Time to Cut, 61; Size of Seed, 61; Amount of Seed per Acre, 63; Relative Value of Bud and Stem Ends and the Middle of the Tuber, 66; Viability, 66. CHAPTER VII Varieties 70-90 Selecting a Variety, 70; Cooking Quality and Flavor, 70, 72; Yield, 70, 74; Ability to Resist Disease, 71, 76; Color of Skin and Tuber, 71, 76; Nature of the Skin, 71, 78; The Shape, 71, 78; Depth and Frequency of Eyes, 71, 79; Time of Maturity, 71, 79: The Haulm, 71, 80; The Leaf, 71, 81; The Vigor of the Variety, 71, 82; Second Growth, 71, 85; Trueness to Type, 72, 85; Test- ing Varieties, 86; The Relationship of Variety to Soil, 87; The Most Popular Varieties, 87. CHAPTER VIII Planting 91-104 Distance Apart, 91; Depth of Planting, 93; Influ- ence of Depth of Planting on the Depth at Which Tubers Form, 94; Influence of Depth on Quality, 96; Date of Planting, 96; Influence of Late and Early Planting, 97; Methods of Planting, 97. CHAPTER IX Management of the Growing Crop. . 105-110 Cultivation, 105; Systems of Culture, 106; Hills, 106; Drills, 106; Level Culture, 107; Method of Cultivation and Tools Used, 107; Mulching, xio. CONTENTS Xi CHAPTER X PAOES Obstructions to Growth and Develop- ment 111-127 Influence of Season and Climate, iii; Weeds, 112; Diseases Due to Parasitic Fungi and Bacte- ria, 112; Late Blight or Rot, 112; Early Blight or Leaf Spot Disease, 118; Potato Rosette, 118; Scab, 119; Diseases in Storage, 121; Wet Rot, 121; Dry Rot, 122; Stem Rot or Bundle Blacken- ing, 122; Bacterial Diseases, 122; Insects, 123; Flea-beetle, 123; Potato Bug, 124; Potato Worm, 125; Potato Stalk Weevil, 126; Grasshoppers, 126; June Bug, 126; Wireworms, 127; Striped Blis- ter Beetle, 127; Arsenical Poisoning, 127. CHAPTER XI Sprays and Spraying 128-142 Fungicides, 12S; Bordeaux Mixture, 12S; Mixing, 129; Testing Bordeaux Mixture, 130; Strength of Solution, 130; Bordeaux Dust or Dry Bordeaux Mixture, 130 ; Washing Soda and Copper Sul- phate Mixture, 131; Benefits from Use of Bor- deaux Mixture, 131; Time of Spraying, 134; Number of Sprayings, 134 ; Insecticides, 135 ; Paris Green, 136; Lead Compounds, 137; Arsenic and Lime, 13S; Cost of Spraying and Profits De- rived, 139; Spraying Machines, 140. CHAPTER XII Harvesting 143-146 Digging, 143; Methods of Digging, 143; Diggers, 144. xii CONTENTS CHAPTER XIII PAGES Storing 147-152 Piles, 147; Cellars, 149; Construction of Cellars, 149; Ventilation and Temperature, 150; Losses in Storage, 151. CHAPTER XIV Production, Transportation, and Mar- kets 153-165 Factors Influencing Farm Prices, 157; Modes of Selling, 159; Local Markets, 159; Distant Mar- kets, 160: Commission Rates, 160; Grading, 162; Packages, 162; Barrels, 162; Bushel Boxes, 164. CHAPTER XV Chemical Composition and Feeding Value 166-170 Composition, i66; Digestibility, i68; Feeding Value, 168; Cooking, 169; Uses, 170. CHAPTER XVI Breeding and Selection 171-177 Propagation and Breeding, 171; Selection, 175. Appendix 179-180 Spray Calendar, 17S; Seed Treatment, 179. Index i8i ILLUSTRATIONS FIQ. PAGE Spraying in a New York Potato Field . Frontispiece 2 Copy of Engraving of the Virginian Potato from Gerard's "Herbal," 1636 2 3 Sectional View of Potato Flower 4 4 Tuber, Showing the Arrangement of the Eyes . . 6 5 Potato Plant, Showing Tubers (Viewed from Above) 12 6 Potato Plant, Showing Tubers and Roots (Side View) 13 7 A Useful Type of Spring-tooth Harrow 22 8 A Disk Harrow , . . . 23 9 A Double-action Cutaway Harrow 24 10 The Influence of Lime Upon Potatoes 36 11 Potato Tray for Storing and Sprouting Seed ... 53 12 Potato Planted Four Inches Deep, Showing its Growth and Development of Tubers 55 13 Seed Potatoes Sprouted for Use in the Planter . . 56 14 Seed of Early Potatoes, Sprouted for Hand Planting 56 15 Seed Potatoes, Showing Weak, Long Sprouts ... 57 16 Diagram, Showing the Stand of Twenty Plats of Carman No. 3 Potatoes 68 17 Diagram, Showing the Stand of Thirty-six Plats of Early Trumbull Potatoes 68 18 Section of a Tuber of Poor Cooking Quality ... 72 19 Section of a Tuber of Good Cooking Quality ... 73 20 Three Varieties Differing in the Character of Net- ting of the Skin 77 xiii xiv ILLUSTRATIONS FIG. PAOE 21 Three Favorite Shapes of Potatoes 79 22 Potato Plant, Showing Upright Haulm 8o 23 Potato Plant, Early Variety, Showing Dwarf Haulm 92 24 The Modern Method of Planting Potatoes .... 98 25 Planting by Hand 99 26 Sectional View of the Aspinwall Potato Planter . . 100 27 Aspinwall Potato Planter (Side View) loi 28 The Robbins Improved Planter 103 29 Platform of the Robbins Improved Planter . . . 104 30 Halleck Expansible Weeder 107 31 Five-tooth Cultivator, with Ililler Attachment . . 108 32 A Useful Two-horse Cultivator 109 33 One-horse Spring Tooth Cultivator no 34 Section of Potato Leaf, Showing the Parts and Mycelium of Blight (F/iytop/iihora irift'stans) . . 1 14 35 Maturation of a Spore Sac and Germination of a Spore of Rot {P. in/estaiis) 115 36 Longitudinal Section of a Potato Stalk, Showing a Germinating Spore of Rot (P. htfestans) . . . . 116 37 The Germinating Tube of a Spore of Rot (P. infes- t(7t!s) on a Leaf 117 38 Tubers with and without Scab 120 39 The Cucumber Flea-beetle (^Crcpidodcra Epitrix cncn- iitrris) 123 40 Leaflet of Potato, Showing Over a Hundred Holes Made by Flea-beetles 123 41 Sprayed and Unsprayed Portions of a New York Potato Field 133 42 A Suggestive English Spraying Machine .... 140 (13 The Reuther Potato Digger 145 44 The Hoover Digger 146 45 Potato Shovel 147 ILLUSTRATIONS XV riG. PAGE 46 Storing Potatoes in Pits 148 47 Showing the Distribution of Potato Production in the United States in 1899 . 154 48 Showing the Distribution of the Area in the United States in Potatoes in 1S99 155 49 Grading and Barreling Potatoes for Market . . . 163 50 Potato Flower, with Calix and Corolla Removed, Showing Anthers and Stigma 173 51 Pistil of Potato Flower, Showing Parts . . , , . 174 ABBREVIATIONS USED U. S. D. A. — United States Department of Agriculture, in connection with reports or bulletins. E. S. R., V:33 — Experiment Station Record, Volume V., page 33. Issued by the United States Department of Agriculture, Office of Experiment Stations. Experiment Stations in the various States are designated by the common abbreviation for the State — as, "Wis.": Wisconsin. Where there are two stations in a State, the particular one is designated — as. New York (N. Y.) Cornell. The number of the bulletin follows. Some States issue their bulletins in volumes, thus: Tenn. Bui., Vol. XI., I., p. 116 — Tennessee Bulletin, Volume XL, No. I., page 116. Pa. D. A. — Pennsylvania Department of Agriculture. State Departments of Agriculture are abbreviated in this manner. Can. Exp. Farms Report, 1901, p. 117— Canada Experi- mental Farms Report for 1901, page 117. Ont. Agr. Col. and Farm Report, 1898, p. 158— Ontario Agricultural College and Farm Report for 1S98, page 158. Hort. Trans., Vol. I. — Horticultural Transactions of Eng- land, Vol. 1. Nat. His. of Car. — N'atural History of Carolina. By Mark Catesby, F.R.S. Second Edition. London. Proc. Assoc. Prom. Agr. Science— Proceedings of the Association for the Promotion of Agricultural Science (America). THE POTATO CHAPTER I HISTORY AND BOTANY The potato {So/annDi tuberosum), also called "white potato," "Irish potato," "English potato," or "round potato," is a native of the elevated valleys of Chili, Peru, and Mexico, one form of it being found as far north as Southern Colorado. The wild potatoes of Chili diifer from the cultivated form, in that they produce seed-balls more freely. Tobacco, tomato, egg^-plant, capsicum, henbane, and .vi*"^ bdladonna all belong to tlie potato family, but of '^ ^ this large family of 1600 species but six bear tubers. Some of these latter — as, Darwin's potato (ySolaiitim viaglia) — were thought to have some value for cross- ing to produce a blight-proof new race, but so far success has not been attained in the latter respecft. A variety of Solanum commersoui, another tuber-bearing plant, is now being boomed in Europe as a substitute for the common potato. The Arizona wild jxitato {Sola7iu)n jainesii) has been grown for many years in this country in various places, but its tubers are small and of little value. The Mexican or Central American potato (So/anu/u tuberosum var. borcale) is found native in Colorado. THE POTATO fig. 2 — copy of engraving of the virginian potato in Gerard's "herbal," printed in 1636 (Compare with photograph, Figs. 5, 6.) In England the name Virginian potato was used to designate its source. The potato was probably introduced into that part of the United States now known as Virginia and North CaroHna between the middle and close of the sixteenth century. It is claimed that in 1586 colonists returning from Virginia probably took the potato with HISTORY AND BOTANY 3 them to England. The Spanish had previously carried it to Europe. Gerard's " Herbal," published in 1597, describes the potato, and the edition published in 1636 contains a woodcut representing the potato as it ap- peared about three hundred j-ears ago (Fig. 2). The potato was more readily appreciated in this country than in Europe, and by the year 1722 it was a common article of food among the whites and Indians in Vir- ginia and Carolina.' In Europe, with the exception of Ireland, potato growing made little progress until the middle of the eighteenth century. The potato (^Solanuvi tuberosum) is an annual, but is virtually perennial by means of its tubers. It has smooth, generally solid, more or less quadrangular, herbaceous stems, which often attain a hight of two to five feet. The stems are often furnished with membra- nous wings at their angles, and bear compound leaves formed of oval leaflets, between which are often found small, leafy growths. The flowers (Fig. 3 ) are borne in clusters, and have an entire, wheel-shaped, five-pointed corolla, varying in breadth from one to one and a half inches, and in color from pure white to purple. It is often claimed that many varieties do not flower, and of those which do a great number never bear fruit. This dearth of fruit is generally attributed to lack of pollen. In many varieties the stamens have degenerated, or do not open to let the pollen out." Conditions seem to have an influence, as a variety may bear abundance of pollen and mature seed in one distridl, but not in another in the same 3'ear. > "Nat. His. of Carolina, " by Mark Catesby, F.R.S., 2d ed. - Halstead, Proc. Assoc. Prom. Agr. Science, 1888, p. 33, " Potato Flowers and Fruit." THK POTATO The idea is prevalent that potatoes do not bloom so freely now as formerly. The fadls do not tend to con- firm this. Tvlark Catesb}-, who was in this country in 1722 and 1726, wrote that " in Virginia and to the FIG. 3 — SECTIONAL VIEW OK POTATO FLOWER (DiagramDialic) a— Ovarj-. A— Ovules, which finallj' become seeds, c — Calyx, made up of green-colored leaves, rf— Stigma. The pollen attaches itself at this place. ^— style, down which the pollen-tube passes to the ovarj- and ovules. /—Petals, white to purple in color, j— Stamens. The thick upper portion bears the pollen, and is known as the anther. north thereof, they [potatoes] are annuals, and produce no flowers, while in Carolina and the Bahama Islands they produce flowers." Many varieties existed at that time, particularly in Virginia, and five kinds were common — the Common, Bermudas, Brimstone, Carrot, HISTORY AND BOTANY 5 and Claret potatoes. The Bermuda potato was the only one that had a white flower, the flowers of all the other kinds being purple. This was the only variety that had a white skin, and was white fleshed. It was round in shape, more tender, and more delicate to raise than the others, and did not keep so well.' George Don, in 1831, enumerates several English earh' varieties, and saj's that ' ' none of the above sorts, when true, produce blo.ssoms." '" At Wyoming Experiment Station,^ in 1895, out of 56 varieties grown 14 did not bloom, but in 1896 but 4 varieties failed to bloom out of 56, and only one va- riety', Blue Victor, failed to bloom in one of the two 5^ears. In other parts of the State all the varieties grown came into bloom. In New York, during 1904, the variety Blue Vidlor was profuse in its bloom, and bore abundance of seed-balls. Out of 300 varieties I have followed closelj^ having grown manj^ for several years, I find that it is seldom that a variety will not bloom at some time in its life, and I am sure that many of the heaviest-yielding varieties bloom as freely as those of inferior merit. At Wyoming Experiment Station the ten heaviest 3'ielding varieties all came into bloom both in 1895 and in 1896, in experiments con- ducted in various parts of the State. The fruit, or seed-baU^, is a globular or short oval berry, either green or green tinged with violet, brown, purplish, or j^ellowish in color, and from three-quar- ters to one and a half inches in diameter. It contains > " Nat. His. of Carolina," by Mark Catesby, F.R.S., 2d ed. » Don's "Gardener's Dictionary," 1831-8, Vol. IV., pp. 400-406. » Wyo. Bui. 32, pp. 54-63. THE POTATO small white kiduey-shaped seeds embedded in the midst of a green and very acrid pulp (Fig. 3). These seeds are sown for the purpose of raising new varieties. The main vertical underground stem varies in length with the depth of planting. This stem branches at in- tervals, and each branch enlarges at the end to form a tuber (Fig. 12). Usually from two to four roots start from the vertical underground stem at the base of each tuber- bearing branch, but roots may start where such branches are absent. This charadleristic growth may be seen by grow- ing a potato in a barrel half full of soil and manure, and watering it well; then, as the stem grows, place soil round it, thus increasing the length of the underground portion and the number of tuber-bearing branches. The tubers may be formed above ground, and whenever they are abundant in the axils of the leaves there are few or none below ground. The tuber is an underground stem, and the eyes on it are equivalent to the leaf buds on a stem of a 3-oung peach or ailanthus. They are arranged more or less spirally in both cases (Fig. 4). From the eye a num- ber of buds may start; hence, in the case of new and expensive varieties, the tubers may be split through the FIG. 4 — KIDNEY-SHAPED I'OTATO {Does Pride) Showing the alignment of the eyes, and that the ter- minal buds tend to start first. Note the short, thick, desirable shoots. HISTORY AND BOTANY 7 e3es, if desired, and a shoot obtained from each half. As each shoot sets a root it may be broken off and trans- planted, and another may start. By these means and great care a pound of seed tubers has been made to yield 2,558 pounds of potatoes in one season. Historical A^ote. — The early history of the potato is obscure. The most authentic information I have secured is that Sir Robert Southwell, the President of the Royal Society of Eng- land, at the meeting held December 13, 1693, stated that the potato was brought into Ireland by his grandfather, who ob- tained tubers from Sir Walter Raleigh, after the return of his expedition from Virginia. This was in the year 1584. It is now believed that Sir Walter Raleigh fitted out this expedi- tion, but did not lead it personally, and never was in Virginia. Timbs' "Curiosities of History," page 233, places the date of its introduction to the British Isles as 1586. CHAPTER II SOME CONDITIONS INFLUENCING GROWTH AND DEVELOPMENT It is common knowledge that a certain amount of heat and an adequate supply of air and moisture are essential for plant growth. All plants that have green leaves require light, in addition, to enable them to as- similate carbon dioxid from the air, dissociate it into its component parts, and elaborate the carbon into such complex substances as starch, sugar, and other carbo- hj'drates. Influence of Light on Yield. — E. Pagnoul' placed colored glass over different potato plants. Two plants under darkened glass elaborated 3 1 and 20 grams of starch respedli vely , while those under ordinary glass elaborated 170 and no grams; at the same time plants under normal conditions elaborated 223 and 361 grams. To the favorable influence of abundant light this writer attributes the large yield of potatoes in a season when the aggregate number of hours of sunshine is unusually large. At Wisconsin Experiment Station coldness and cloudiness were believed to be the causes of a poor yield.^ The Amount of Moisture. — The amount of water the plant can obtain from the soil is closely cor- K. S. R., v., p.116. '■' wis. Report, 1902, p. 188. 8 SOME CONDITIONS INFLUENCINO GROWTH 9 related \vitli llic mode of development. If tlie soil is ver3' dry, and particularly if the tuber is cut, the seed tuber may be so weakened bj^ loss of moisture that it cannot grow. If a tuber has access to but a small amount of water, there will be little or no root devel- opment, with little formation of leaf shoots, but tubers will be formed. Advantage is taken of this fadt when small early potatoes are required, the tubers being placed in sand, in a cellar, when small tubers will form, but none or few leaves. Under certain conditions, with an abundance or excess of moisture, numerous leaf shoots and roots appear, but no tubers. An increase in the supply of moisture in the air has been found to favor the development of leaves on the shoots, where only scales were formed in an insufficient supply of moisture. Respiration. — We may say that all plants breathe or take in oxygen and give off carbon dioxid. With potatoes this is a necessary funcftion, and if checked, growth is injured. It is probable that light induces some conditions more favorable to increased respira- tion than darkness; hence, if the objedt is to store pota- toes, it will be better to hold respiration at its lowest point and keep them in the dark. Respiration cannot go on without force or energy, and as this must be supplied, at least partly, from the tuber, it follows that ac1;ive respiration will be attended by loss of weight, and this goes on very rapidly when the tuber sprouts. If we wish to " sprout" tubers, the best conditions for doing so are still undetermined. Influence of Temperature on Respiration. — All plants have a range of temperature at which respi- lO THE POTATO ration is normal. The minimum, optimum, and max- imum temperatures have been ascertained for some plants. Young wheat plants will respire at as low a temperature as 28° F., or below freezing-point. The optimum temperature for wheat is about 104° F., while that of potato plants is about 113° F. The maximum for wheat is 113° F., while that for pota- toes is about 131° F. In other words, the potato respires best at about 113° F. , but should the temper- ature go above 131° F., the respiration will be some- what less than before, and the vitality weakened ; hence, after a hot spell, when the temperature exceeds the maximum for respiration, it is noticeable that the potatoes fail and become more susceptible to the blight or other troubles, owing to their impaired constitu- tion. By sele(5lion we might procure plants of greater vitalit}', capable of standing the higher temperatures, which would enable them to be better ' ' disease-resist- ers." Present-day potatoes thrive best in a cool climate. Influence of Temperature on Growth. — The minimum temperature for germination of potato tubers is about 50° F. ; hence, in the Northern States early planted tubers make little or no growth unless planted shallow, and this is not desirable, except, perhaps, for the earliest varieties. It is better to germinate the tubers in the barn before planting, thus saving time (see Chapter VI., " Sprouting Potatoes"). Potato Roots. — Generally speaking, far more at- tention has been paid to the stems and leaves of plants than the roots, yet in order to cultivate the soil in a rational manner it is essential to know where the roots SOME CONDITIONS INFLtl^CING GROWTH II are their charaAer, and requirements. Examination of therootsof Early Ohio potatoes,^ made July 5, i899. forty-three days after planting, about the time the crop recdved its third cultivation, showed that at tins time there was little growth of fibrous roots-only the skele- ton system supplied with numerous delicate root hairs. The seed tuber appeared to be sound and whole, but on closer examination it proved to be but a shell. Only a few eyes on the upper side of each tuber produced shoots; thus one hill produced three stalks from two eyes, and another had seven stalks springing from five eyes The latter plant had more numerous but smaller roots than the former. Twenty-five small potatoes were set on the first plant, the largest of which were the size of a laro-e pea. At this stage of development the mam portion^of the roots was in the surface eight inches a few roots reached to the depth of eighteen inches but the greatest root growth was in a horizontal diredion. The roots from each hill had already met and interlaced, some having reached a length of two feet the plants being three feet apart. At six inches from the hill some of the main lateral roots were but two and one-quarter inches from the surface of the ground, while midway between the rows their depth was barely three inches from the surface. Further examination of Early Ohio potatoes seventy- two days after planting, when the tubers were nearly full size, showed that the main root growth was m the upper foot of soil ; several of the large horizontal roots were within three inches of the surface, and one was but one inch deep. Some of the vertical roots reached 1 N. Dak. Bui. 45: P- 54i- 14 THE POTATO a depth of two and a half feet. The deep-growing roots are very tender and brittle and easily broken, differing in this respecft from corn roots. The hori- zontal roots send out vertical branches, which often descend to a depth of two feet or more. Shallow tillage, such as hand-hoeing without hill- ing, retains all the roots. Moderately deep tillage with a five-tooth single horse-cultivator and slight hilling destroys pradlically all the surface roots, and undoubtedly interferes seriously with the plant's de- velopment ; while with deep tillage nearly all the long horizontal roots are destroyed, and with them all their numerous vertical branch-roots with their intricate system of fibres and root hairs, by which the potato receives its food. In very heavy soils it may be wise to plant potatoes shallow and then hill them, but in most soils it is better policy to plow deep, plant fairly deep,, and give shallow flat cultivation. With deep tillage the roots nearest the surface were at a depth of seven inches, while in the case of those receiving shallow tillage the bulk of the horizontal roots were in the sur- face seven inches. The hilling covers the potatoes and prevents them from sunburning, and this seems to be all the benefit received. The loss of roots is very hurtful, and takes place at a time when the plant can least afford to suffer injury. Experiments conducfled at Vermont Experiment Station' .show that during the last weeks of growth the weekly increase in weight of tubers is at its maximum, and that checks when the tubers are approaching maturity depress the yield cor- respondingly. > Vcr. Bui. 72, p. 5. SOME CONDITIONS INFLUENCING GROWTH 1 5 A sample of Early Ohio potatoes taken ninety days after planting, when the vines were beginning to die and the tubers were nearly ripe, showed that the roots penetrated to a depth of over two and a half feet.' The branches from the main lateral roots had reached about as deep as those immediatel}' under the hill, and the soil was filled with roots to a depth of about two and a half feet. The system of rooting is similar to that of corn, but the plant is not so good a forager, and the roots do not fill the soil so completelj'; hence, plants can be placed closer together. Late varieties have a similar root system, but root more freely, more deeply (a depth of three and a half feet being common if the soil conditions will permit), and occupj' the ground more completely; hence, require more room than early varieties. At Cornell Universit}', during 1904, many potatoes had horizontal roots in the surface inch of soil. All of these would be destroyed by moderately deep tillage. Influence of Depth of Planting on Roots. — Generall}' speaking, the new potatoes and the roots start out above the seed, although if an under e)-e of the potato produces the shoot the roots and tubers maj^ develop at the side of the seed. Depth of planting has some influence on the depth at which the tubers will form, and may have some on the roots. The question deserv'es investigation. Many plants prefer to send out their roots at a uniform depth below the surface : thus, at Cornell Universit)-, wheat, whether planted six inches deep or one inch deep, will send out its per- • N. Dak. Bui. 43. p. 544. 1 6 THE POTATO manent roots about oue and a half inches below the surface. Blossoming, Tuber Formation, and Hilling. — Potatoes are hilled about the time they come into bloom, and this is the time that tuber formation is beginning. The ancestral type of potato developed seed about this time and died ; the tendency acquired by cultivation is to throw all the reserve material into tuber production. These reproductive processes cause a severe drain upon the plant's energies, and the fort- night immediately following the blossoming period is therefore a peculiarly critical time for the plant, during which time its life hangs in the balance. At this time it is subje(5l to extreme heat, and may be injured; also insedls, fungi, etc., may attack it, and, to add to its troubles, cutting off a lot of its roots, either just before or about this time, is no doubt the common cause of a decline from which the plant never recovers. Even tuber formation , without the influence of other agen- cies, may cause a plant to die. The importance of studying the condition of the plant at this time will be appreciated when it is remembered that the entire crop of salable tubers is formed after this critical period is past, and full success with the crop depends upon retain- ing the plant healthy for from one to three months after the blossoming period. During August, in one case,' the crop of potatoes increased at the rate of over 50 bushels, or over 3,cx)o pounds, weekly per acre. The importance of avoiding checking growth prepara- tory to or during suchji,.^Bj^iievident. y 1 Ver. Bui. 72, p. 5. CHAPTER III SOILS The soil considered best is a deep, mellow, free- working loam, grading either to a sandy loam or clay loam, although the crop may be raised on lighter or heavier soils, provided the latter are drained. Tile drainage should be resorted to, if necessary, to reduce the water table to from 3 feet 6 inches to 4 feet below the surface. Some reasons forseledling a light, sandy, or gravelly loam for the crop are : 1 . Such soils can be worked early in spring, and gotten ready for early planting, if desired ; 2. The lighter soil becomes warm more readily in the spring than a heavier soil, and germination of the tuber and growth of the plant proceeds more rapidly ; 3. They can be easily worked, and placed and main- tained in good tilth without a heav}^ labor bill ; 4. The efifedls of the manures and fertilizers applied are generally perceptible for a longer period of time than on lighter soils ; 5. The potatoes grown on such a soil usually come out bright and clean, smooth and of more uniform size — important fa(5lors when they go on the market ; 17 l8 THE POTATO 6. Light soils usually produce potatoes of better qual- ity, because they tend to shorten the growing period by cutting off the moisture supply, and thus forcing the potatoes to mature earlier; 7. Those grown on well-drained sandy loam soils usu- ally keep better than those grown on stiff clay soils. Aroostock County, Maine, is famous for its potatoes.' Its soil presents a gently rolling surface, and is com- posed essentially of drift deposited during the melting of the ice after the ice age, and resting on a stratum of limestone, which in many places comes to the sur- face. The soil partakes of the general nature of drift containing a considerable portion of sand and the usual amount of organic matter. It is peculiarly suited to potatoes, because it does not pack after hard rains nor during periods of drouth. Its open and porous nature permits the free development of tubers and the ramifi- cation of the roots. The soil was originally covered with a growth of hard and soft woods, consisting chiefly of maple, cedar, birch, white poplar, spruce, hemlock, and pine. The forest growth Vv^as dense, and in clear- ing large quantities of ashes were produced, which fitted the virgin fields particularly for the produ(5lion of large crops of potatoes. After a few years of culti- vation, the CKop-producing power of the soil showed a diminution, and to-day applications of farm manures and commercial fertilizers containing a large percent- age of potash are resorted to. Analyses of Maine soils show that they are silicious, contain considerable or- » U. S- »• A., Div. of Clicmistry, Bui. 5«, P- 5-8. SOILS 19 ganic matter, and are reasonably rich in lime and mag- nesia, which seem to be essential constituents of a soil suited to the growth of potatoes. The potash is also in fair quantity, but not sufficient to produce maximum crops. The famous potato-growing counties of Wiscon- sin, Portage, Waushara, and Waupaca had over 60,000 acres in potatoes in 1899, and these are as important to the Central States as Aroostock County, Maine, is to the Eastern States. The soil is glacial drift, some of it being made up of level deposits of sand and gravel covered Avith a light loam. The sand is usually un- derdrained by a bed of coarse gravel. Sandy loams prevail. Clayey loams occupy some areas, but are not prevalent. The average ^deld is 100 bushels per acre. On Long Island, N. Y., the chief potato soils on the south side of the island are light silt loams underlain either by gravel or sand, while gravelly till is the main type on the northern side. The yields Y-ary from 80 to 250 bushels per acre. The Influence of Soil on Different Varieties. — Professor Buff um,' of Wyoming Experiment Station, reported on eight varieties grown on each of two kinds of soil represented on the experiment farm. The soil and crops were treated alike. Plat i is bench-land above the river, and is a deep red colluvial soil con- taining little humus. Plat 2 is bottom-land next the river, and is a black soil containing a large amount of humus. 1 Wyo. Bui. 32, p. 6. 20 THE POTATO TABLE I VARIETY Yield %r acre Plat 2 Yield per acre Increased yield on Plat 2 Beauty of Hebron Early Mayflower Early Puritan Empire State l,ate Puritan Pride of the West Snowdrop White Elephant ; Lbs. 9,678 15,060 12,702 15.372 18,858 5i040 14.562 11,808 Lbs. 23.628 28,842 32,340 22,698 26,742 23,322 25,500 27,990 Lbs. 13,950 13,782 19,638 7,326 7,884 18,282 10,938 16,182 Average 12,885 26,383 13,498 The figures taken colledlively show the importance of seledting a soil suitable for the crop to be grown, the yield being doubled on Plat 2, while taken indi- vidually it is evident that certain varieties were better adapted to the environment than others. The ques- tion of which variety will best suit the environment must be determined by the grower. Subsoiling. — Buffum', of Wyoming, states that sub- soiling may be recommended throughout that State for potatoes. The cost of subsoiling to a depth of 1 6 inches to 18 inches varied between $3.00 and ^6.00 per acre. Hays^ of Minnesota, found it to be expensive and not profitable under most conditions in that State, and that it reduced the yields of crops on land already suffi- ciently open and porous. In humid climates, if at- tempted; it is advocated that subsoiling be done in the fall, to permit the readjustment of the soil granules before springtime, so that the moisture will be able to rise upward from the subsoil, as evaporation takes ' W'yo. Uul. 41, \>\i. 20. 21; Hul. 32, pp. 7, S. Minn. Bui. 68, p. 609. SOILS 21 place at the surface, and prevent the crop being de- stroyed by lack of moisture. Injurious results from subsoiling in spring have been noted, probably due to the working of the subsoil when it was too wet. It does not follow that because the surface soil to the depth of eight inches is dry enough to plow the subsoil will be, and in many cases the subsoil has been puddled by spring working, and the supply of moisture from below more or less completely cut off, with disastrous results to the crop. Preparation of the Soil. — The ideal crop to pre- cede potatoes is timber, but as no rotation comprising this crop is in use, the preparation given after timber demands little attention. Potatoes are more commonly grown after potatoes, corn, or after clover or sod. In such cases preference is usually given to fall plowing, accomplished during Odtober or November until freez- ing prevents further work. Deep plowing should be done in fall, because opportunity is then given for the storage of water in the soil during the winter and when the thaw occurs in spring. If manure is to be applied it is spread before plowing, but, if rotted, it may be applied later and disked in. The depth of plowing varies with the soil, probably six inches or eight inches being most common, although, if the soil will permit, eight inches to twelve inches will be better. When soils are deficient in humus, it is generally inadvisable to plow deeply. The humus content of such soils should be increased and the depth of plowing increased correspondingly, thus bringing the land into a higher state of producflion. In some distri(fts where the snow covers the ground all winter the land is harrowed well 22 THE POTATO in fall and left nearly ready for planting, thus facilita- ting spring work. Where the frost penetrates deeply, or the soil is apt to run together, the land is better left rough plowed all winter and fitted in spring ; but this entails some loss of time, and prevents the early plant- ing of potatoes. vSometimes it is necessarj' to plow in spring, and in many cases it is profitable to replow when a fall plow- FIG. 7 — A USEFUL TYPE OF SPRING-TOOTHED HARROW ing has been given. Under such conditions a depth of not more than six inches or eight inches is advised, because plowing land is attended by loss of moisture, and in most cases the amount of moisture held in the soil or supplied as rainfall during the growing period is insufficient to insure maximum yields ; hence, care should be taken to conserve all the moisture possible by plowing judiciously, making and maintaining a mulch of the surface soil, thus checking evaporation, SOILS 23 and by enriching the soil in hmnus either by manuring or a suitable rotation. Humus affedts the physical properties of the soil considerabl)^ — among other things, enabling it to hold more moisture without injury to the plants in a wet time, and to endure drouth in a FIG. 8 — AN EFFICIENT PULVERIZER; THE DISK HARROW dry time.' Even where irrigation is practiced the above fadtors cannot be economically neglecfted. Surface-fitting Tools. — The Acme harrow is one of the best tools for making a soil mulch before the crop is planted, and in trials made by Sanborn" was shown to be the most efficient type of harrow for pul- verizing soil. On stony land, or where roots of trees interfere, the spring-tooth harrow (Fig. 7) is preferred for deep tillage of the soil, while under other conditions 1 Minn. Bui. 68, pp. 576-579. - Utah Bui. 4. 24 THE POTATO the disk harrow. These tools work deeper than the Acme harrow, aud may be used to prepare the soil to a depth of four to six inches, which seems to be as deep as is necessary. Few farmers prepare land to this depth, as it requires three horses on a six-foot harrow on a loam soil. Two to 2^^ inches is more common. Harrows differ in their action; thus, the spring-toothed harrow FIG. 9— DOUBLE-ACTION CUTAWAY HARROW and the smoothing or spike-tooth harrow tend to com- padt the soil while fining it, while the disk type (Figs. 8 and 9 ) and Acme harrows tend to lighten it and make it more open when they fine it. For potatoes and corn the latter are preferable, while for wheat the former. Whatever tool i,s used the land should be well fitted. Few farmers prepare the land well enough, and many SOILS 25 would find it more economical and profitable to spend another week working the land than to rush the crop into a badly prepared seed-bed. The soil under the plants and near them cannot be touched when they have been planted, while wide tools may be used before. CHAPTER IV ROTATION In some cases potatoes are grown continuously for several years on the same soil, but a rotation of crops is preferable for many reasons — among others, to lessen the dangers of attacks of diseases and insects, and to bring the soil into a suitable physical condition for growing this crop. Some rotations suggested by Wheeler, of the Rhode Island Experiment Station,' are as follows: three-year rotation — potatoes, winter rye, common red clover; four-3'ear rotation — corn on clover sod, potatoes, winter rye, clover. This can be made into a five-year rotation by seeding timothy and redtop with the clover, and leaving the mixture down two years, thus reducing the labor bill to some ex- tent. Trials of these and other rotations were made on land so poor that corn attained a hight of but 4 or 5 inches, while the first crops of salable potatoes were but 65 bushels per acre. During later years, with management similar to that given the first year, and the application of a similar amount of fertilizers, the yields ran up to 350 bushels of salable potatoes per acre. A common Maine rotation is a four-year course of potatoes, oats, clover and grass, the latter for two years — it being noted that clover thrives on good po- tato land. In deciding upon the rotation it is important 1 K. I. Bui. 74, 75, 76. 26 ROTATION 27 to note the influence of eacli crop upon the moisture content of the soil (see p. 50); thus, rye removes less moisture from the soil than wheat. Oats draw heav- ily upon the moisture content. The potato crop is not usually considered to be a heavy water consumer. It leaves the soil in a rela- tively moist condition; hence, the wisdom of the Maine four-year course, in which oats succeed potatoes. This course requires but one deep plowing in four years, that for the potatoes, and in this it is econom- ical. Peas use a relatively small amount of water, and would leave the soil in good shape for potatoes. In Wisconsin,' while potatoes grown in rotation yield- ed 342.8 bushels per acre, a crop grown on an old alfalfa sod yielded but 277.7 bushels per acre, al- though the rainfall was considered adequate to pro- duce a full crop. In some cases clover tends to leave the soil drier than some other crops, and its use as the preceding crop for potatoes may be detri- mental. In most cases, however, a leguminous crop is the best to precede potatoes. In Florida" cow-peas preceding potatoes increased the yield 40 per cent. The Ohio Station^ found that in the three-course rota- tion— potatoes, wheat, clover — whenever good crops of clover were grown the economy of using nitrogenous fertilizers for the potatoes was questionable, thus show- ing that a good rotation is equivalent to manuring. Plowing under a leguminous crop is held to be good practice on farms where an adequate suppl}' of manure is not forthcoming and little stock is kept; thus, a-t the 1 wis. Report, 1902, p. 188. ' Fla. Report, 1900-1901, p. ' Ohio Bui. 125, p. 132. 28 THE POTATO Maryland Station,' plowing under a crop of crimson clover increased the yield 34.4 bushels per acre, or 50 per cent., and the average gain for two years was 27 bushels per acre, or 4.5 per cent.; the Storrs' (Connedt- icut) Station reports that clover sown in corn at the last cultivation had a high value when used to plow under as manure for potatoes, even though it only attained a hight of three or four inches ; in Germany^ the sweet clover {Meli lotus alba) is found to be a valu- able green manure; while in another German experi- ment,* where clover was seeded in rye which was grown for grain, the clover being plowed under the following spring, it was noted that the yield of rye was dimished, but the yield of the succeeding crop of potatoes was increased. The yields of rye and potatoes were : TABLE II CROP Yield per acre of rye, 1892 Yield per acre of potatoes, 1893 Bushels Lbs. Bushels Lbs. Rye alone 1 1 44 15 21 n 50 12 35 289 35 296 15 Kye and late sown red clover Kye and early sown red clover 330 25 430 39 As green manuring for poor sandy land on Long Island, N. Y., Professor Stone, of Cornell University, suggested sowing a bushel of cow-peas and ten pounds of crimson clover per acre, in July, with some fertil- " Md. Bui. 38. p. 58. ' E. S. R., v., p. 701. ' Conn. (Storrs) Report, 1900, p. 65. * E. S. R., VI., p. 292. ROTATION 29 izers. The cow-peas were killed by the first frost, but the clover persisted; the crowding, however, was such that the plants of neither crop got too large before be- ing plowed under the following spring. For farther north a combination of half a bushel of buckwheat and a peck to half a bushel of rye per acre, sown together, has given good results. Rape sown at the rate of four to five pounds per acre is useful. Other crops will suggest themselves. In parts of New York, especially on heavy loams, buckwheat is esteemed as the preceding crop for potatoes. It crowds out weeds and leaves the soil in excellent physical condition. CHAPTER V MANURING AND FERTILIZING lyAND is manured and fertilized either to increase or to maintain its crop-producing power. Whether this is secured by the diredl effedl of the chemical ingredients in the manure or fertilizers, or by their influence upon the physical properties of the soil, or both, is an unsettled scientific problem, but all agree that under certain con- ditions the addition of manures, fertilizers, and water to the soil is profitable. Whether it will be profitable on a particular farm or field, and the manure, fertil- izer or combination of fertilizers which will be most profitable to use, are questions the grower must settle for himself by trial. No chemical examination of the soil yet condudled has shown why two soils, apparently identical in chemical composition, should not produce similar yields of crops. Experience has shown that the chemical composition of the soil is no guide to its crop-producing power. Hence, all that can be given in this chapter is to submit mixtures of fertilizers that are used and the role the different important ingre- dients are believed to play in the plant economy. In addition to water, which is treated elsewhere, four elements are frequently applied in various chem- ical forms as fertilizers — nitrogen, phosphorus, potas- sium, and calcium. The potato through its life re- (juires liberal supplies of the first three of these elements, and its behavior in regard to these is similar to that of 30 MANURING AND FERTILIZING 3I a shallow-rooted root crop. The fadls that the potato is a starch-producing crop, and that its period of growth is through the summer and extending well into autumn must be remembered. In these features it is similar to corn, but distindlly different from the cereals which ripen in the summer, as it is assumed that it is able to utilize the nitrates and other plant-food liber- ated during the summer and fall. E. Hecke' states that the demand for nitrogen is especially strong dur- ing the first half of the vegetative period, while the demand for potash is greatest during the second half of the growing period, and that potash aids in the for- mation of starch, and especially in the development of tubers and roots, although the effe(5ls were observed in all parts of the plant. The Influence of Nitrogen. — Wilfartlr showed that when the supply of nitrogen is insufficient the leaves tend to turn 3'ellow, and that if the available supply of potash is deficient heavy applications of nitro- gen tend to reduce the percentage of tubers and starch. Lawes and Gilbert' show that nitrogen stimulates the producflion of starch, provided the mineral constituents are not deficient; but in large quantities nitrogenous fertilizers stimulated luxuriant growth, delayed matur- ation, and produced potatoes richer in nitrogen and much more liable to disease. At the Rhode Island Experiment Station* dried blood ranked first of the nitrogenous fertilizers applied, followed by nitrate of .soda and sulphate of ammonia; but on .soils said to be extremely acid, dried blood was only about half as I E. S. R., VII., p. 667. 2 K. S. R. XIV., p. 561. » Rothamsted Memoirs, Vol. VI. * R. I. Bui. 65, pp. 133, 134. 32 THE POTATO beneficial as it should be; hence, such soils need liming before full benefit can be derived from the use of this fertilizer. A mixture of two-thirds dried blood and one-third nitrate of soda, or of equal parts of all three fertilizers, is suggested. At the Tennessee Experiment Station' cottonseed-meal was found to be a more profit- able source of nitrogen than nitrate of soda, while at the Florida Station" the nitrogen of cottonseed-meal and castor pomace were equally effedtive, but that of nitrate of soda was more so bj' 30 per cent. The Influence of Potash. — Wilfarth and Wim- mer ' show that when potassic fertilizers are applied to a soil almost destitute in potash they-r- 1. Increase the size of the tuber, but have little influ- ence upon its composition, and that the amount of potash in tubers remains fairly constant, unin- fluenced by the amounts in the soil, or applied, unless very heavy applications are made, which may cause an increase to a certain point, but will be attended by a decline if contituied. 2. Decrease the percentage of stems and leaves, but have no marked influence on the roots of potatoes. 3. Have a marked influence on the shape and appear- ance of the leaf; if deficient, the leaves are j'ellow- ish-brown in color, and become spotted or striped in the portions between the veins, while the peti- ole of the leaf and ribs retain their dark green color. If the supply of potash is insufficient the leaves tend to curl, and sometimes collapse of the plant follows. I Tenn. Bui., Vol. XIII., No. 3, p. 6. « Fla. Report, 1900-1901, p. 27. » K. S. R., XIV., p. 561. MANURING AND FERTILIZINCt 33 4. Increase the quantity of water transpired per gram of dry matter, Hecke' shows that the application of potassic fertil- izers has a marked influence in the produdlion of tubers and roots, and that potash assists in the forma- tion of starch. L,awes and Gilbert' noted that the percentage of potash was relatively high when the supply of it was relatively liberal and vice versa, but the variations are small, and that where there was a deficiency of potash in the supply and in the ash there was generally an increased supply of lime in the ash. Which is the Better Source of Potash, Sul- phate or Muriate of Potash ? — This question is still unsettled, because, apart from other considerations, one of the deciding factors is the relative cost of each. In man}' cases the results are Inconclusive,' while in some cases^ the fertilizers appear to be of equal value. In others^ sulphate of potash gave better results; thus Davidson, of Virginia," found that the potatoes grown b}' sulphate of potash contained more dry matter but a less percentage of starch than those fertilized with muriate of potash. Brooks' found that sulphate of potash gave a greater yield per acre of merchantable tubers, which were of larger size and of superior eat- ing quality, containing 2 to 3 per cent, more starch, and, when cooked, the potatoes were whiter, cf better flavor, and more mealy. 1 E. S. R., VII., p. 6G7. - Rolhamsled Memoirs, Vol. VI., " Experi- ments on the Growth of Potatoes." ^ (N.Y.) Geneva Bui. 137, pp. 604, 620. * N. H. Bui. 41, p. ];,. ^ Mass. (Hatch) Report, 1S96, p. 22; R. I. Bui. 65, p. 133 ; Mich. Bui. 131, p. 10; (N. V.) Geneva, Bui. 137, pp. 621, 622. * Va. Bui. 92, pp. 107, loS. ' Mass. (Hatch) Report, 1904, p. 122. 34 1*HE POTATO The time and method of application must be con- sidered. In my experience muriate of potash has given better results when applied the previous fall, especially if more than loo pounds per acre are to be applied, the presumption being that the potassium compound under- goes changes in the soil, and that the injurious chlorine is removed as a chloride by the winter and spring rains. For spring application in the drills sulphate of potash may be better, or a mixture of sulphate and mu- riate of potash, if more than the above-mentioned quantity is required. The disadvantage of the muriate of potash seems to be due to the fact that it is a chlo- ride, and Sjollema' and Pfeiffer^ have shown that the chlorides of potassium, sodium (common salt), and mag- nesium, when added to the sulphate of potash, dimin- ished the starch content of the potatoes considerably, and that the redudtion was greatest in varieties rich in starch. This would seem to support the common idea that sulphate of potash produces better quality potatoes than muriate of potash. Wheeler,' of Rhode Island, shows that calcium chloride had a marked poisonous effect upon potatoes and nearly destroyed them, while the same amount of calcium in certain forms other than the chloride or sulphate increased the yield and vigor of the plants. New varieties, and those making a heavy growth of haulm, seem to be particularly sensitive to chlorides. Influence of Phosphoric Acid. — lyack of phos- phoric acid is accompanied by dark green leaves. While phosphoric acid aids starch formation, it is often re- ■ E. S. R., XII., 434. ' K. S. R., XII., 443. » R. I. Bui. 40, pp. 85, 86. MANURING AND FERTILIZING 35 garded as being of less importance than polsash. The results obtained at the Ohio Station ' show that phos- phoric acid is the most essential fertilizer for their con- ditions, some potash, and, in some cases, nitrogen, being also required. I found the same to be true at Briar- cliff Manor, N. Y., where lOO pounds of available phosphoric acid per acre (equal to 600 pounds acid phosphate, 16-17 per cent, available) gave profitable returns. My own observations are that an excessive application of available phosphoric acid has a marked influence upon the foliage, causing it to be small, dark green, wrinkled, and apparently stunted in develop- ment, with consequently early maturity. In some cases the period of growth is reduced six or eight weeks, and consequently the yield is low; but, owing to the potatoes being mature, the quality is generally good. In certain localities, for early potatoes, where it is desirable to hasten maturity, the use of fair quan- tities of acid phosphate, with a limited supply of nitro- gen and potash and no barn manure, is found to be good pradtice. The nitrogen may be supplied in an available form as nitrate of soda, since nitrification may not be adlive in the soil during the early period of growth. The Influence of Calcium. — Calcium does not aip- pear to be so important as some of the other elements, although in some cases it produces a marked increase in yield (Fig. 10). If applied in a form which has an alkaline a(5tion upon the soil — as, carbonate of lime or quicklime — it may have an injurious effedl by >OhioBul. 125, pp. 131, 132, 36 THE POTATO producing conditions which aid the development of scab. Barn Manure. — Applying barn manures is com- monly pradliced for potatoes with profitable results. Lawes and Gilbert ' showed that only a small portion of the nitrogen of farm manures is taken up by the crop; thus, with an annual manuring of 15.5 tons per acre, containing 200 pounds of nitrogen, continued for twelve Courtesy K. 1. Kxp. Sla. See Bui. ■)». FIG. lO — INFLUENCE OF LIME UPON POTATOES Showing the influence of lime upon the yield, and that it increases the per- centage of scabbed potatoes. Jiiglit, unlinied. Left, limed. Other fertil- izers the same in both cases. 5'ears, but 8.3 per cent, of the nitrogen was recovered in the crop. ' ' These results seem to indicate that this crop is able to avail itself of a less proportion of the nitrogen of the manure than any other farm crop. Yet, in ordinary pradlice, farm-yard manure is not only largely relied upon for potatoes, but is often applied in larger quantities for them than for any other crop." Taft,^ of Michigan, found that twenty-four loads of manure per acre gave the largest yield, while at the ' Rothamsted Memoirs, Vol. VI. - Mich. liiiK iji, p. lo. MANURING AND FERTILIZING 37 Wisconsin Experiment Station twenty loads per acre were applied, and larger quantities in Great Britan. It seems natural to assume that the beneficial effedls of manure must largely be due to other causes than the addition of plant- food. Among these may be its influence on the physical properties of the soil, render- ing it more retentive of moisture, more porous and more permeable for air and roots, and a better home for the useful soil bacfleria, which, in fact, it may sup- ply. The decomposition of such quantities of organic matter, with the consequent liberation of carbon dioxid, aids in rendering the mineral resources of the soil more available. Generally speaking, it is more economical to apply about ten tons of manure per acre and supple- ment it with fertilizers, except upon loose open soils of poor texture, where the beneficial effedl from the larger amount should probably be ascribed to its in- fluence upon the retention of moisture. It is preferable that the manure be rotted somewhat and applied the previous fall, while the fertilizers maj- be applied when planting. On some soils, to reduce the danger of dis- ease, it may be advisable to apply all the barn manure to the previous crop. The application of fertilizers is profitable under most conditions in the Eastern and North Central States. At New Hampshire Experi- ment Station the application of fifteen cords of manure increased the yield of marketable potatoes over loo bushels per acre compared with no manure, and the use of 1 ,500 pounds of fertilizers with the same amount of manure resulted in a further increase in yield of 130 bushels per acre.' Taft,^ of Michigan, shows that ' N. H. Bui. Ill, p. 116. 2 Mich. Bui. 131, p. 10. 38 THE POTATO the average gain from the use of a full application of fertilizers was eighty bushels per acre. In Long Island, N. Y., a fertilizer mixture containing 4 per cent, nitrogen, 8 per cent, available phosphoric acid, and 10 per cent, potash has proven satisfadlory. It is used in amounts varying from 500 pounds to 2,000 pounds per acre, and in many cases more potash is ap- plied than is profitable. The use of 1,000 pounds of this fertilizer has given the greatest profit. Where 1,500 pounds or 2,000 pounds were used the cost of the fertilizer was more than the market value of the in- creased yield of potatoes. For some years I have used a mixture of 100 pounds sulphate of ammonia, 400 to 600 pounds acid phosphate (16 to 17 per cent, available), and 100 pounds muriate of potash with eight to ten tons of partiall}^ rotted manure per acre on a medium loam soil. At New Hampshire Experiment Station' 300 pounds muriate of potash per acre gave the best results when compared with none, 150 pounds, and 450 pounds per acre. The above mixtures merely show quantities used by certain individuals ; each farmer must work out a mix- ture suited to his needs. There are other conditions than the application of fertilizers. As Dr. W. H. Jordan* pithily puts it: "It is clearly evident that a large supply of plant-food does not necessarily insure a satisfactor}' crop. Other conditions which largely per- tain to culture — such as texture, humus, and water- supply — exercise a controlling influence, and when these conditions are unfavorable their effedt is not over- come by heavy applications of fertilizer. ' ' 1 N. H. Bui. Ill, p. 115. "^ (N. Y.) Geneva Bui. 189, p. 215. MANURING AND FERTILIZING 39 It almost invariably occurs that potatoes grown with- out any manure mature earlier and contain more dry matter, with a correspondingly reduced yield,' than those grown on land manured with barn manures or a complete fertilizer. The vigorous growth induced under the latter conditions cannot be matured in the same time, hence for an early crop it is unwise to stimulate too vigorous growth. The Function of Fertilizers. — The prevailing opinion in purchasing fertilizers is that they contain a certain amount of plant-food — usually nitrogen, phos- phoric acid, or potash — in a more or less available form, and that the benefits received from their appli- cation is due to the addition of this plant- food to the .soil. So deeply seated is this theory that all fertilizers are bought and sold on this basis, and laws controlling the business have been formulated upon it. The in- gredients— nitrogen, phosphoric acid, and potash, with others — are necessary for the growth of all crops, but the amounts of the essential ingredients, other than the above mentioned, are believed to be present in the soil in sufficient quantities to meet all the requirements of the crops grown. A 300-bushel crop of potatoes has been found to con- tain 81 pounds of nitrogen, 30.6 pounds of phosphoric acid, and 79 pounds of potash. Taking 49 New York .soils, the chemist found that the surface eight inches contained, per acre : ^ Nitrogen . . . 3,053 pounds, enough for 38 crops Phosphoric acid, 4,219 " " " 137 " Potash .... 16,317 " " " 207 " I Va. Bui. 92, p. 107. - (N. Y.) Cornell Bui. 130, p. 157. 40 THE POTATO Upon such soils as these applications of fertilizers containing phosphoric acid, and, in some cases, potash, have been found, by experience, to be most profitable — a condition of affairs which could never be ascertained from the analyses. It is seldom that the increase in yield of crop bears any relationship to the quantity of the fertilizers applied. Without either fertilizers or manure, but given good tillage, yields of 300 bushels of potatoes per acre have been obtained for four suc- cessive years on the same piece of land . ' The amount of plant-food removed by an)- crop is small, and is obtained from all parts of the soil wherever roots extend . Most soils contain certain sufficient plant- food to supply the demands of any crop grown thereon for an indefinite period of time. To maintain crop pro- du(5lion at a profitable point, attention must be paid to fadlors other than the supply of plant-food. The ingredients applied as fertilizers will, no doubt, be found to have a value other than their value as car- riers of plant-food. Their value for this purpose may- be found to be small, while the benefits derived from their use ma}' be found to be largely due to their chemical adlion upon the soil — e.g., as sanitary agents, promoters of the growth of desirable organisms or de- stroyers of injurious ones, aids in the formation of de- sirable chemical compounds in the soil or neutralizers of inidesirable compounds, to their influence as stimu- lants, and upon the physical properties of the soil. That their use is desirable in some cases is evident. Why it should be, and how, are matters for investiga- tion. 1 (N. Y.) Cornell Bui. 191, p. 192. MANURING AND FKRTII.IZING 4I The farmer needs to realize that the soil on his fields to-day is not the same as that of last year. Soil is changing. The subsoil of yesterday is the soil of to-day. Although the amount removed by crops is so small that it is a negligable quantity, that removed by washing and by the wind is enormous. The muddy stream, the bars at the mouths of rivers, the move- ment of soils by the wind, and even the dust-cloud raised when harrowing, show that far more plant-food is removed in these ways than in crops, and to check these leaks is of more importance than to try to make up the loss by the addition of plant-food. The main- tenance of a satisfatSlory amount of organic matter in the soil in a proper condition maj^ usually be accom- plished by a judicious rotation of crops, manuring, and liming. ' ' The old method has been to feed crops with com- mercial fertilizers, the new agriculture looks to nature for its sources of plant-food. These sources are (i) the large stores of unavailable plant-food in all soils, (2) the unlimited stores of nitrogen present in the air.'" Research has revealed the fadl that soil or- ganisms can take plant-food from both of the above sources and furnish it to growing crops, and that a fertile soil is one in which these processes are going on at the highest rate, and that it is necessary to stimu- late these biological activities. Humus is a food for these organisms. Lime is essential for maintaining the soil in a slightly alkaline condition, and for fixing some of the compounds formed in the soil; and drain- ' Del. Bui. 66, p. 14. 42 THE POTATO age, deep plowing, and thorough tillage are necessary to bring air into the soil and stimulate badlerial adliv- ity. Humus, lime, and tillage are three important fac- tors in maintaining a fertile soil,' and the farmer who understands the value of these is the one who will de- rive the most benefit from the use of fertilizers. Purchasing and Applying Fertilizers, — Fertil- izers may be divided into three classes — viz. : (a) Nitrogenous, or those rich in nitrogen. (d) Phosphatic, or those rich in phosphorus. (c) Potassic, or those rich in potassium. Nitrogen occurs in fertilizers, as : (i) Nitrates — e.g., nitrate of soda, nitrate of potash. (2) Ammonium salts — e.g., sulphate of am- monia. (3) Organic nitrogen — e.g., dried blood, tankage, hoof meal, etc. Nitrogen as nitrates is immediately available as plant- food, is soluble in water, and if not taken up quickly by plants is liable to be lost in the soil water; hence small quantities applied at short intervals give the best results. Nitrogen as ammonium salts soon becomes available in warm weather, and is not so liable to be w^ashed out of the soil as when in the form of a nitrate. Nitrogen as organic matter is more slowly available. » Del. Bui. 66, "Soil Bacteria and Nitrogen Assimilatioa." MANURING AND FERTILIZING 43 Phosphorus occurs in fertilizers, as : ( 1 ) Insoluble phosphate of lime — e.g. , floats, bone meal, tankage. (2) Soluble phosphate of lime — e.g., acid phos- phate, dissolved bone. Insoluble phosphate of lime is considered to be but slowly available. It is converted into " soluble " by treating it with an acid, usually sulphuric acid. Soluble phosphate of lime, as a rule, is more active than insoluble in promoting plant growth, but on acid soils insoluble phos- phate often gives better returns. The soluble phosphate of lime and a phosphate soluble in weak acids constitute the ' ' avail- able phosphoric acid ' ' of the chemist. Potassium is the valuable ingredient found in : Wood ashes, kainit, sulphate of potash, double salts, and muriate of potash. It usually gives good returns w^hen applied to light, sandy, and peaty soils. As kainit contains chlorides and muriate of potash is a chloride, it is often advisable to apply them some time previous to planting the crop, in order that the injurious substances may be removed by the soil water, chlorides, in excess, being injurious to potatoes. Value. — All fertilizers may be valued according to the percentage of nitrogen, soluble phosphate of lime, insoluble phosphate of lime, and potash present. They are often valued on the unit system. A unit is one per cent, of a ton, or 20 pounds; the ton, 2,000 pounds. 44 THE POTATO Unit Value. — In order to find the unit value of the different ingredients, divide the price per ton of the fertilizer by the percentage, or number, of units of the various valuable ingredients; this will give the cost per unit. For example, if sulphate of ammonia be $66.00 per ton and contains 20 per cent, of nitrogen, then 66 -^ 20 = 3.30 per unit (see Table, p. 45), If the price per pound be desired, divide the price per unit by 20, or the number of pounds in the unit; thus, 3.30 H- 20= 16.5 cents per pound. For a fertilizer containing several ingredients, find the lowest cost of each ingredient in a standard fertil- izer— as, nitrate of soda for nitrogen, muriate of potash for potash, and acid phosphate for soluble phosphoric acid — and compare it with these. Purchasing Fertilizers. — In purchasing fertilizers it is advisable to w^ite for quotations with guaranteed analj'ses, ascertain, as indicated above, the cheapest source of the valuable ingredients, and then purchase. The fertilizer containing a unit of plant-food at the lowest cost is generally the one to bm*. In figuring the cost always include the freight, cost of hauling, and handling; for instance, one ton of nuiriate of pot- ash contains as much potash as four tons of kainit, hence the potash as muriate of potash costs only one- quarter as much for haulage and handling. The same applies to high grade acid phosphate and low grade, and unless the filler is of some particular value it is wise to take the high grade or concentrated goods. Barn Manure. — When not applied to the fields as soon as made, it should be stored under cover and the excrete from the various farm animals mixed, MANURING AND FERTILIZING 45 TABLE III SHOWING THE COST OF THE DIFFERENT INGREDIENTS IN CERTAIN FERTILIZERS DURING 1904 VALUABLE INGREDIENTS COST NAME OF FERTILIZER ■5: .■5 s 0 C •28 1^ Per Ton Per Unit Per Lb. Nitrate of Soda .... 15-5 20 13 II 4 $ 44.00 65.00 45.00 3S 00 $ 2.84 3-30 3^46 3-38 2.84 .76 2.84 .80 2.84 •91 2.84 i^57 .85 .94 1. 00 1. 00 I 00 I 00 86 Cts. 14.2 16.5 I7.3 16.9 14.2 3-8 14.2 Sulphate of Ammonia . Dried Blood (high grade) Dried Blood 1 Fresh Bone Meal . . ■ 1 2S.00 26.00 27.00 34.00 11.00 15 00 40.00 12.00 26.00 48.00 43.00 1. 10 1.24 ■ 22 ■ ■ ■ : : 1-25 Steamed Bone Meal . -^ 2S 40 14.2 Fine Ground Bone } Tankage 1 5 14 4-5 14.2 Fine Ground Bone _) 7 9 78 Acid Phosphate .... Acid Phosphate .... 13 16 40 47 5^o 5^0 5^o 50 4^3 Acid Phosphate .... 12 26 48 50 Double Salts of Potash and Magnesia .... Sulphate of Potash. . . Analj'sis of a ton of ( •45 I I 42 38 43 42 38 43 •54 ' .61' '•9 Another sample of \ .63 .14 ■ ' .67 19 Manure 1 when the cold cow and pig manure will tend to pre- vent excessive loss, bj- heating, from the horse ma- nure. Young growing animals and tho.se bearing young and giving milk will give poorer excrete than 46 THE POTATO mature fattening animals. The food and the litter used also affect the value of the manure. In barn manure the nitrogen, phosphoric acid and potash are slowly available, and are arbitrarily reck- oned to be worth half what they would cost in fer- tilizers. The value of a ton of manure for its physical effect upon soils cannot be expressed in dollars and cents, but in the Eastern States it may be presumed to vary between 50 cents and $1.00 per ton; for while the fertilizing ingredients show a value of about $1.25, the manure often costs, or is valued at, $2.00 per ton. Mixing Fertilizers. — Fertilizer manufacturers lay great emphasis on the value of proper mixing, and usually charge from $5 to $10 per ton for doing it. For example, a commercial potato manure analyzing nitrogen, 3 percent., phosphoric acid, 6 per cent., and potash, 10 per cent, costs in New Hampshire', in 1904, $36.50 per ton. A fertilizer made up by the station on the same formula was just as satisfactory, and after allowing $1.00 per ton for mixing, it cost $24 per ton, a saving of $8.50 per ton, or using 1,500 pounds per acre = $7- 10 per acre. To compound this fertilizer: 3 per cent, nitrogen := 60 pounds nitrogen in a ton (2,000 pounds). 6 per cent, phosphoric acid = 120 pounds phosphoric acid in a ton. 10 per cent, potash = 200 pounds potash in a ton. Nitrate of soda will furnish nitrogen for immediate use, and the nitrogen of the sulphate of ammonia will ' N. H. Bui. III., p. 110. MANURING AND FERTILIZING 47 become available later on, hence we may take 23^4^ pounds nitrogen in the form of nitrate of soda, and 36^ pounds in the form of sulphate of ammonia. Cottonseed-meal, dried blood, tankage, etc., might also be used if desired. Pounds Nitrate of soda containing 153^ percent, nitrogen; to fur- nish 23I4 pounds nitrogen it requires 150 pounds . 150 Sulphate of ammonia containing 20 per cent, nitrogen; to furnish 36?^ pounds nitrogen, it requires 1S4 pounds 184 Acid phosphate containing 16 per cent, available phos- phoric acid; to furnish 120 pounds phosphoric acid it requires 750 pounds 750 Muriate of Potash containing 50 per cent, potash; to furnish 200 pounds potash it requires 400 pounds . 400 Filling, sand, etc., used to make weight if desired . . 516 2,000 Unless care be taken in mixing fertilizers loss of valuable ingredients may result. 1 . Nitrate of soda and soluble phosphate of lime — as, acid phosphate — must not be mixed and allowed to stand for any length of time, or chemical a(5lion will take place, resulting in a loss of nitrogen and phosphoric acid. 2. Do not mix an ammonium salt — as, sulphate of am- monia— with any other fertilizer containing free lime, as the lime will set free the ammonia, which will be lost. 3. Do not mix soluble and insoluble phosphates to- gether. 48 the; potato 4. Nitrate of soda is ver}^ deliquescent, and if left mixed with other fertilizers is liable to render the whole mass wet and pasty, and so difficult to apply. Cottonseed-meal is a very useful source for part of the nitrogen of mixtures. If it is nec- essary to hold a quantity of nitrate of soda for a time, it is advisable to empty it out of the bags, as they are liable to ignite spontaneously. When emptied do not leave the bags lying in a heap in the corner of the barn. Store nitrate of soda in a dry place. 5. Kainit is also very deliquescent, and it is the worst potassic fertilizer to use in a mixture on this ac- count. Sulphate or muriate of potash are better for mixtures. Applying Fertilizers. — When a horse planter is used the fertilizer is usually distributed in the row at the time of planting. The fertilizer may be sown broadcast or in the rows as desired, but it should be incorporated with the soil and not left on top. Water Requirement. — It has been shown clearly that the available water content of the soil exerts a great influence upon the life of the potato plant, upon its assimilation of plant-food, and upon the yield. At the Wisconsin Experiment Station ' it was found that when two acre inches of water were added in. two irri- gations in one case the 3'ield was increased 100 bushels of salable potatoes per acre, thus showing that the right amount of water at the right time is a very im- portant factor in determining the yield. Whitson,'' of » wis. Report, 1899, p. 213. ^ Wis. Report, 1902, p. 190* MANURING AND FERTILIZING 49 Wisconsin, shows that if it is assumed that under the existing dimatic conditions of that State i8 inches of rainfall during the growing season is sufficient for po- tatoes, then, on this basis, there was a shortage of 4 inches or more in ten of the past twenty-one years. In Utah ' it was noted that the largest yield was obtained from a plat irrigated every eighth day and receiving 14 inches of water, and another year '^16.62 inches of water v.'ith pra(5lically no rain produced a yield of 423 bushels per acre. The importance of water was also shown at the same station,^ when amounts of water varying be- tween 4.3 inches nnd 9.45 inches were applied between July 18 and August 6, and the yield increased with the increase in amount of water. At the New Jersey Station* irrigation increased the jdeld 36.4 per cent., while at Wisconsin the increase has been 159.58 ^ bush- els per acre over the unirrigated plat, and the average gain per year during the six years — 1 896-1 901 — was 83.9 bushels per acre. That some risk must be taken in irrigating heav}^ soils in a humid climate was demonstrated at Wisconsin.'^ Thus, in one year, while there was an increase of 81.4 bushels per acre from irrigating sandy land, on heavier land the yield was reduced 56 bushels per acre because heavy rain followed the second irrigation. Corn and potatoes require somewhat similar amounts of water to make one pound of dry matter. The figures of Wilfarth and Wimmer ' and Whitson* are as follows: > Utah Report, 1893, p. 180. » Utah Bui. 26, p. 14. » Utah Bui. 5. * W. J. Report, 1900, p. 184. • Wis. Report, 1901, p. 198. « Wis. Report, 1900, p. 18S. » K. S. R., XiV., p. 561, « Wis. Report, 1902, p. 191, 50 The potato WATER USED PER POUND OF DRY MATTER WHITSON WILFARTH AND WIMMER Pounds Potatoes . . . 200 to 230 Tobacco . . . 300 to 370 Buckwheat 400 Chicory 400 Mustard 500 Oats 460 Pounds Corn 270 Soy-beans 527 Clover 576 Oats 503 King ' has shown that the amount of water required to make one pound of dry matter in the tuber and vine of potatoes varied between 272 pounds and 497 pounds during the years 1892-7, while that for oats ranged be- tween 446 and 595 pounds; barley, 375 to 404 pounds; peas, 477; com, 223 to 398 pounds; clover (first crop), 370 to 582 pounds; clover (second crop), 730 to 983 pounds. "Irrigation and Drainage." K. H. King. CHAPTER VI CONSIDERATIONS OF SEED Source of Seed. — It is often advised that potatoes be obtained from another soil and from a more north- ern latitude if vigor and delayed maturity are desired, and from a southern latitude if earliness is sought; but, general^ speaking, potatoes bred for a distridl do better there than elsewhere. Few European varieties of potatoes are worth growing in America, and any in- troduction requires acclimatization and sele(5lion. In England we noted that northern grown Scotch seed did not yield so heavily the first year as the second, and the same was true of Maine grown seed in the Hudson River valley. Brooks,' of Massachusetts, and Bishop, of Maryland, report exadlly to the con- trary, although in a subsequent 3'ear Brinkley,^ at the same station, obtained higher yields from home grown seed. The Rhode Island Station' found that varieties which produced large yields gave increasing yields the longer the seed tubers had been home grown, and that those which produced smaller yields gave diminishing yields the longer the seed had been home grown. At Louisiana Station^ home grown seed was equal to, if not better, than w^esteru, or eastern grown or Boston seed. At Georgia Station"' southern grown seed did 1 Mass. (Hatch) Report, 1S96, pp. 25, 26. ■■' Md. Bui. 37, p. 257. * K. I. Report, 1897, p. 3^0. * I,a. S»cond Series lUil. .(, p. 77. »Ga. Bui. 17, p. 166. 51 52 THE POTATO best, and the statement is made that the value of seed depends more upon the care exercised in the seledlion of the strain than the locality where it is grown. Martinet', of France, reports that in several diversified trials seed tubers from higher altitudes gave better yields under all circumstances. Bailey", of Cornell, lodges a criticism against the comparison of northern and southern grown seed. He believes the variations to be due much more to the stock itself — how the plants have been grown and handled in previous years — than to any influence of latitude. He believes it to be impossible to secure stock from different growers which is suiSiciently uni- form to allow of comparative experimentation. That such variation exists is shown by Brooks'' observ^ation on Beauty of Hebron and Early Rose potatoes. Seed potatoes of the same variety obtained from different localities gave a variation in 5'ield of about 50 per cent, for each variety. Probably the matter is one of indi- viduality. It is necessar}^ to study each potato and hill, and perpetuate a variety suited to the particular environment. If this variety possesses the capacity of adapting itself rapidly to other environments it is more useful, but it must be able to grow vigorously and mature its tubers in order to maintain its value. The Ohio Experiment Station* found that the selecftion and storage of potatoes is of more importance than the use of seed grown on other soil. Kansas Experiment Sta- tion"^ found that tubers matured in July were the most > E. S. R., XII., p. 636. = (X. Y.) CDriicU Uiil. 25, p. 175. ' Mass. (Hatch) Report 1899, p. 82 ■• Ohio Bui. 76, p. 46. " Katis. IXil. 37, pp. 155, 136. CONSIDERATIONS OP SEED 53 satisfadlory seed for the second crop, and the pradlice of nsing first-crop tubers as seed for the second crop is rapidly gaining ground in the South, owing to the difficulty of holding seed over. Management of Potatoes Previous to Plant- ing.— The best way to hold seed potatoes is in cold storage at a temperature of 33° to 35° F. Should the temperature fall to freezing-point (32° F.) for a short 2' 6 KIG. II — A USEFUL POTATO TRAY FOR THE STORAGE AND SPROUTING OF SEED POTATOES For small quantities, a useful size is 24 x 12 inches. This size will hold about forty pounds of tubers, and can be conveniently handled. The larger size holds about eightj' pounds of tubers. time probably no harm will result, as the freezing- point of potatoes is rather lower than that of water. As most farmers do not have cold storage some sub- stitute must be found. A cool, fairly dry cellar, or a root-house, is a very good alternative, or, failing this, the potatoes may be pitted outside and covered so that no frost can reach them (see "Storing"). Several weeks before planting the tubers should be spread out on the barn floor two or three thick, in the light, to quicken growth. Potatoes varj- in the time they take 54 THK POTATO to germinate. Mature potatoes will not begin to grow until they have had a period of rest. In some varie- ties this may be but a few weeks, while others may be held months before they show signs of growth. In the island of Jersey and the .early potato grow- ing districts of the United Kingdom it is customary to store the .seed potatoes in flat traj's (Fig. ii). The advantages of these are : ( i ) the seed cannot heat ; (2) a large quantity can be .stored in a room, the traj'S being tiered almost to the roof; (3) seed can be easih' examined at any time and convenient!}' moved, hence disea.se.s — as, wet-rot, dry-rot, etc. — are more ea.sily con- trolled; (4) the potatoes may be sprouted in the trap's; (5) the potatoes can be moved to the field in and planted from the trays. The tray is the best means of storing new varieties which have been purchased or grown in small quan- tities. Sprouting Potatoes. — L,avallee' and many others have found that sprouting seed potatoes in a well- lighted room increases the yield and earliness, and produces a more vigorous growth of vines and a larger starch content in the tubers. One explanation offered for the increase in yield is that the short, thick stem developed under the above conditions bears many scales or leaves for its hight, and it is from the axils of these scales, the place where the scale joins the stem, that the tuber-bearing branches are produced (Fig. 12). The more .scales produced, the more op- portunity for the development of tubers. If the tu- bers start growth in the dark, either indoors or below 1 K. S. R., XII., p. 1032. CONSIDERATIONS OF SEED 55 ground, the scales are formed at longer intervals, and there are correspondingly fewer places for the produc- tion of tuber-bearing branches. Also, in the latter I'IG. 12 rOTATO PLANTED FOUR INCHES DEEP {Diagrammatic) (j_Ground level. /'—Seed potato, r— Short sprout .sent up before plant- ing, which sent up two branches, d. <-\ rf being broken off, and c cut off at/. ir — The tuber-bearing stem, or rhizome, which bears buds at h, and thickens at the end to form a tuber, /, upon which eyes having buds, k, may be seen. in is a tuber-bearing branch, or rhizome, which has not yet begun to form a tuber, and r shows where the roots were broken off. Generally four roots are sent out for each tuber-bearing branch. case, the leaf-bearing branches produced above ground are weaker. The system is considered essential in the island of Jensey and the early potato growing dis- tridls of the United Kingdom, .and is practiced to a .small extent for the ..second crop in the Southern States. F'grs. 13, 14, 15, courtesy Cornell Univ. Dept. of Horticulture. FIG. 13 — POTATOES SPROUTED PROPER LENGTH FOR THE PLANTER Starting the growth of the tubers in this way is profitable in many places. VU:. 14— KAliLV POTATOES SI'RoUlEi) FOR HAND PLANTING Longer sprouts than these should not be permitted to develop. 50 CONSIDERATIONS OF SEED 57 By sprouting the seed tubers, the Kansas lixperimeut Station' have planted potatoes in March and lifted the crop on June i. At the Rhode Island J'.xperiment Sta- tion" potatoes were held in a fairly well-lighted room at a temperature of 60° to 75° F. for four to six weeks. -, P flR51SI™«B ^otI^? ■^ '^f^-^'T -^^ FIG. 15 — SPROUTS TOO LONG AND WEAK This often occurs when potatoes are left in sacks, barrels, or in piles in tile cellar. As soon as sprouting begins, spread the tubers thinly on the barn floor, in the light, to check this waste of energy. In this time thick buds, one-half to an inch long and one-quarter to three-eighths of an inch in diameter, formed (Fig. 14). The potatoes maj' be held at this stage for some weeks if necessary by lowering the tem- perature. Early Rose potatoes weighing about three ounces each were sprouted as described, and planted on May I beside similar tubers which were unsproutecL • Kan. Bui. 70, p. 149, and Press Bui., March 6, 1899. *R. I. Bui. 36, pp. 9-19. 58 'rHi<: poi\\'i'o Part of the crop was harvested Jul}- 29, the 3deld being decidedl)' in favor of the sprouted seed, which lead was maintained (see Table). TABLE IV riEI,D PER ACRE EROM SEED TUBERS SPROUTED AND NOT SPROUTED Sprouted Not sprouted. Sprouted Not sprouted. Date Harvested July 29 . . . July 29... Aug. 20. . Aug. 20. . YIELD PER ACRE Large Tubers Small Tubers Bushels Bushels 97.96 53.23 76.10 42. 7S 135-47 94-45 .55-51 41.90 Total B ushels I51-I9 118. S8 190.98 136-35 Gain bv Sprouting Bushels 32-31 54-63 Increase front Further Growth Bushels 33-79 '7-47 In trials made at Cornell Station by the writer dur- ing 1904, with the varieties Sir Walter Raleigh and Carman No. 3, increased yields of from 0.9 per cent, to 73.7 per cent, resulted from sprouting potatoes in the light for 36 days previous to planting, when com- pared with holding them in a root-cellar to the time of planting. The sprouts on the tubers held in the cellar were up to three inches long; those held in the light were but one-half to three-quarters of an inch long. No misses occurred, except from those sets held in the cellar. It seems probable that each variety may have its own optimum temperature, as conditions were uni- form for both varieties. Eighteen hills were used in a plat, and Table V., on page 59, .shows the results. Another great advantage in sprouting is that it gives an opportunity to note variation and "rogue" the variety. Almost every variety .shows a difference in the sprout, either in color or habit of growth; one CONSIDERATIONS OP SEED 59 may have a white, spindl}- stem, whicli becomes green on exposure; another a short, sturdy stem, which be- comes bright red; while another may be purple, and so on. So far I have found the "sprouting stage" the most reliable one at which to note differences in varie- ties, and varieties of potatoes may be distinguished as readily as varieties of other crops, TABLE V No. of Plat SIR WALTER RALEIGH Method and Temperature of Germination Cellar 50-60° F... Cold Frame bot- tom heat So° F. sash off Cellar 50-60° F... Barn, near open window 45- 75°F Cellar 50-60° F... Greenhouse 78- 90° F Cellar 50-60° F... Lbs. 17-50 17.00 0.9 16.20 20.12 19.4 17-50 20.25 15-75 CARMAN NO. 3 Lbs. 15-25 26.5 21.25 16.25 16.25 15.00 36.9 The disadvantage of the sj-stem of sprouting pota- toes is that the tubers must be planted by hand on ac- count of the liability of knocking the sprouts off if passed through the planter. There are many local markets in the United States poorly supplied with early potatoes, and to suppl)' such a small area of the crop could be profitably handled as above described. A distin(5lion must be noted between the above method 6o The; potato and the slovenly practice of many who allow their seed tubers to send out long sprouts before planting, which are either broken off intentionally before or unintentionally during planting. This practice cannot be too strongly condemned. The Trays may be made small to hold 40 pounds of potatoes, with a handle running lengthwise across the top, or to contain 80 to 100 pounds, and handled by two men, when the handles run across. The lum- ber for the trays, ready sawn in lengths, should be purchased at from five cents to ten cents per traj-, according to size. Whole Sets vs. Cut Sets. — Considerable atten- tion has been given to the advisability of cutting seed tubers. The question is wholly a financial one, as in an average 3'ear with an ordinar}^ late variet}'' the weight of the seed planted is of more importance than whether it is whole or cut. Early varieties do not do so well when cut, and varieties with white flowers seem to be softer in texture and more liable to failure, if cut, than those with purple or colored blossoms. Some varieties cannot be cut with profit, owing to lack of bud-producing ej-es. The labor of cutting is often greater than the cost of the extra seed. When seed is expensive, as when a variety is new, it is wise to cut as far as possible to secure the largest possible yield in the least time, but this course must be followed by selection, or rapid deterioration of the variety will result. A potato cut into single-eye pieces, and each piece planted in a hill, will give a greater yield than it would had it been planted whole. CONSIDERATIONS OF SEED 6l Time to Cut. — Formerly it was advised to cut the potatoes a few days before planting. Generally speak- ing, this is a mistake. Zavitz ' reports as the result of hundreds of trials, during a period of eight years, that potatoes cut the da}^ of planting gave 8 bushels per acre heavier yield than those cut four to six days before planting. Similar results were obtained at the Montana Experiment Station.^ Size of Seed. — It is a matter of general observa- tion, supported by experiments, that large seed usually insures a larger j'ield than small seed. This may be due to the greater amount of nourishment furnished to the 3'oung plants, which enables them to make stronger growth, and to the greater hereditary vigor possessed by such tubers. Good-sized seed is especially desira- able on light soils, and for early maturing varieties. Smaller seed from vigorous plants may be as satisfac- tory with late varieties, owing to their longer period of growth. The advisability of using large or small seed, cut or whole, depends largely upon the cost of the seed, the season, the culture given, and the price realized when harvested. Generally speaking, tubers weighing two to three ounces make the most profitable seed, as they are worth less for consumption. The amount of experimental work which has been under- taken to decide the influence of the size of the seed tuber upon the yield is enormous, and only a few ref- erences can be given here. Fischer,' of Germany, advises (i) that inider ordi- > Ont. Agr. College aud Farm Report, 1S9S, p. 158; 1902, p. 127. s Mon. Bui. 9, p. 21. ' H,. S. R., IX., p. 331; X., pp. 361-367, 62 THE POTATO nary conditious large seed should be used, (2) on good soils with heavy fertilizing small tubers and closer planting is advisable; but that the small tubers shall be the progen}' of large tubers grown on well-cultivated and fertilized soil, to prevent degeneration. Tubers which are small because the parent plant had not suf- ficient vigor to produce any larger are worthless for seed. At Arkansas Station' whole tubers 2 inches to 3 inches in diameter yielded 18 per cent, more than small whole tubers ^4 inches to i){ inches in diameter, and large cut tubers 15.8 per cent, more than small cut tubers. At the Ontario Agricultural College^ the largest yields for four years in succession were from planting large seed. Sets weighing one-sixteenth of an ounce and having one eye j-ielded, on an average, for the four years, 44.2 bushels, while two-ounce sets having one e3-e averaged 177.4 bushels per acre, and intervening sizes of sets yielded in proportion to their size. As the result of eight j'ears' careful experi- ments, this station advises that large tubers be cut into pieces weighing about two ounces each for sets.' J. C. Arthur,^ of Indiana, conducfled an elaborate set of experiments for three years to ascertain the rela- tion of the number of eyes on the seed tuber to the producl. He found that within certain limits the yield will increa.se with an increase in the weight of the set, and that the exact number of eyes per cutting is rela- tively unimportant. With tubers of the .same weight and variety the number of .shoots does not perceptibly ' .\rk. Bui. 50, p. 2S - Ont. .\gr. Col. Report, 1S9S, p. 156. ' Out. .'Vgr. Col. Report, \'j02, p. 126. * Ind. Bui, 42. CONSIDERATIONS OF SKED 63 increase with the increase of eyes ou the tuber. Seed tubers weighing i^ ounces and carrj-ing 8 to 10 ej^es sent up, on an average, 5.5 stalks per tuber, while seed tubers weighing 3 ounces and having 14 to 18 eyes sent up, on an average, 11.3 stalks per tuber. Bisect- ing an eye tends to increase the number of stalks, be- cause each eye is usually a collecl;ion of buds, and some would be left uninjured on each piece. The number of stalks sent up tended to increase with the size of the seed tuber, and the jdeld increased with the increase in number of stalks. The Virginia Experiment Station ' reports that large seed cannot be used at a profit, while small seed is not recommended, but that sound tubers of the size of a hen's egg and upward are proper seed. Green, ^ of Ohio, found that crops from whole seed mature a few days earlier than from the same sized seed cut in two, and that small cuttings require the .soil to be in better condition than large cuttings, or whole potatoes, in order to secure a good stand and a profitable crop. Amount of Seed Per Acre — Cost and Influ- ence on Yield. — Plumb, ^ of Tennessee Experiment Station, found the largest seed tubers to be most pro- ducfliveand the least profitable, while those varying in weight from one to three ounces were most profitable. At Kentucky I^xperiment Station^ the amounts planted varied from six bushels per acre when medium- sized seed were cut to two e\es to 4S bushels per acre where large whole potatoes were planted. At the ' Va. Bui. S, p. 3. - Oliio Second Series ]iul., Vol. III., I., p. 14. »Tenn. Bui., Vol. III.. J.,p.6. * Ky. Bui. 22, p. 136. 64 THE POTATO TABLE VI YIELD PER ACRE Co5^ oj Value of Balance Amount of seed Distance planted seed per acre at cropper acre at after of seed paving for Seed peracre. Bushels tubers. Ounces apart. Feel Bushels Number of Tubers 7SC. per Bushel 40C. per Bushel 64 12-14 3 146 90,980 48.00 5S.40 10.40 81 10-12 2 220 135,075 60.75 88.00 17.25 66 8-10 2 195 118,102 49-50 78.00 28.50 52 6- 8 2 168 H5.273 39.00 67.20 2S.20 37 4-6 2 158 108,908 27.75 63.20 35-45 26 3- 4 2 146 104,66s 19-50 58.40 38.90 18 2- 3 2 141 81,328 13-50 56.40 42.90 II I- 2 2 128 67,184 8.25 51-20 42.95 Michigan Experiment Station' three varieties were tested, with results as shown in the following table: TABLE VII SIZE OF SEED Amount of seed peracre Yield per acre Net yield in excess of seed Net gain from using halves Halves Quarters .... Eighths Single eyes . . . Whole tubers . . Bushels Lbs. 20 19 9 54 5 44 4 10 41 40 Bushels 317 254 221 1 78 293 Biishels 297 244 215 174 251 Bushels 82 46 The writer has found from .seventeen to twenty bushels to be necessary to furnish a good seeding, and others have advocated the same amount,' although a less quantity is frequently mentioned as satisfadlory. A compilation^ of experiments made at thirteen stations to determine the proper amounts of seed shows: I. Within ordinary limits, an increase in seed pro- duces a marked increa.sc in total yield and marketable potatoes. ' Mich. IMil. 57, p. 18. s JSIich, liul. 93, pp. 5, 6. CONSIDERATIONS OF SEED 65 2. An increase in the size of the seed from cue eyQ to half a potato produces an increase in the net vahie of the crop, A comparison of the half potato with the two eyes shows that : 1. For the total 5-ield (large and small) of 95 ex- periments, 76 are in favor of the half potato and 19 in favor of two eyes. 2. For marketable yield (total less small) of 73 ex- periments, 58 are in favor of the half potato and 15 in favor of the two eyes. 3. For net marketable yield (marketable less amount of seed) of 30 experiments, 23 are in favor of the half potato and 7 in favor of the two eyes. 4. For net value of crop (value of crop less value of seed) of 30 experiments, 22 are in favor of the half potato and 8 in favor of two eyes. A comparison of the whole potato with the half potato shows that : 1. For the total yield (large and small) of 54 ex- periments, 46 were in favor of the whole potato and 8 in favor of the half potato. 2. For the marketable 3'ield (total less small) of 42 experiments, 36 were in favor of the whole potato and 6 in favor of the half potato. 3. For the net marketable yield (marketable less amount of seed) of 13 experiments, 7 are in favor of the whole potato and 6 in favor of the half potato. 4. For the net value of crop (value of marketable less value of seed planted) of 12 experiments, 7 are in favor of the whole potato and 5 in favor of the half potato. 66 THE POTATO The Value of Bud and Stem Ends and the Middle of the Tuber for Seed. — Many ideas have prevailed as to the relative values of different parts of the tuber for seed. Some growers advocate the re- moval of one end or the other, but thus far the ex- periments condudled at a dozen stations, including such varying points as Illinois,' New Jersey,' and North Dakota^ Experiment Stations, show that there is no material difference noticable in yield that could be at- tributed to the different pieces, and that the two ends of a tuber are pradlically of equal value. Viability. — The buds of tubers vary considerably in their ability to grow, and the same is true of the tubers themselves. Goff, of Wisconsin,^ when using the vari- ety Burbank, obtained a stand varying from 88 to loo per cent, of the potatoes planted. The importance of proper moisture content of the soil is shown by the results reported in the following table by Woods, of Maine:' TABLE VIII VARIETY STAND Percentage of Cuttings that Produced Plants Rose . 22 Early Michigan 46 Hulett's Rust Proof 37 Mill's Mortgage Lifter 20 Green Mountain 61 New Queen i Polaris 55 Maggie Murphy 50 Irish Cobbler 65 Early Ohio 57 Gem of Aroostock 28 Bovee 55 ' 111. Bui. 40, p. 132. « N. J. Report, 1898, p. 308. » N. D. Report, 1901, pp. 40-42. ■• Wis. Report, 1897, p. 306. = Me. Bui. 98, p. 1S3. CONSIDERATIONS OF SEED 67 This poor stand was largely due to a very dry spell in May and June, and the differences observed in the various varieties may be due to the vitality of the vari- eties themselves, or to the way in which they were grown and stored, or to both causes. Girard, of France, summarized his experiments some time ago, showing the influence of the size of the tuber upon the " stand " and yield. TABLE IX WEIGHT OF SEED I — Tubers 3.5 oz. each, planted whole .... 2 — Tubers 3.5 oz. each, cut into two portions 3 — Tubers 7.0 oz. each, cut into two portions . 4 — Tubers 10.5 oz. each, cut into three portions 5 — Tubers 1.75 oz. each, two tubers planted together 6 — Tubers i.o oz. each, three tubers planted together Percentage IVeighl of Crop I The 3'ield of No. 2 is not comparable with the others, because the same weight of seed was not used. Plats I and 3 are probabl}' the best to use for ordinary consideration, and would show that from 90 to 95 per cent, of the tubers planted should grow, but it is a well-known observation that under adverse conditions — as, a dry season, ill-fitted land, etc. — a small cutting is not so likely to grow as a whole tuber. The diagram (Fig. 16) shows that with Carman No. 3, where twenty plats were noted, there were 3 chances in 20 that the germination of the tubers and stand would be 100 per cent., and that it is much more likely to be between 91 and 98 per cent, than any other 68 THE POTATO 3 ~ ? i / \ / \ I ^ 11. 0 s 9 9 1 n 5 3 ? 9 } 2 31 90 S3 88 87 86 85 M 83 82 [1 bO 79 78 77 76 7^ FIG. l6 — DIAGRAM SHOWING STAND OF TWENTY PLATS OF CARMAN NO. 3 POTATOES ' The percentage stand is shown on the base-line. The hight of the cuive from the base-line shows the actual number of plats. ffii m i m\ 9876 ,4321 9876„ 432 J ^9876.,^432y^„9876 432/ 9876 W 35 90 85 80 75 70 65 60 FIG. 17 — DIAGRAM SHOWING STAND OF THIRTY-SIX PLATS OF EARLY TRUMBULL POTATOES' The percentage stand is shown on the base-line. The hight of the curve from the base-line shows the actual number of plats. number, although the average as usually worked out would show 93.5 per cent. With Early Trumbull, using seed showing the rosette disease (^Rhi"odonia solani) and some not showing it, treated with various fungicides, the average germina- J From data in Ohio Bui. 145, p. 21, CONSIDERATIONS OI^ SfiBD 69 ting power for 36 plats is 73.8 per cent. Yet, here again this does not convey a true impression, as on six plats all of the tubers germinated, and the table shows that there is a greater chance of securing a stand of between 83 and 98 per cent, than lower.' The viabilit}' of tubers is injured or ruined if they heat or sweat to any extent; hence, if the}^ have been treated with a solution, as for scab, it is essential that the)' be planted at once or spread thinly to dr)\ Po- tatoes may be ruined for seed purposes, if frozen, or if shipped in bags or barrels w^hich have contained sub- stances injurious to the buds — as, sugar, nitrate of soda, etc. ; and even moving them on the farm in unwashed sugar-bags has been found to be dangerous. Immer- sion in water for more than a day may destroy the buds, and probably cause the tuber to decay in a few days. B)^ this means potatoes have been destroyed in pits, and in the field when floods have occurred. Soak- ing them in too strong a solution of formalin or other preservative is liable to reduce viability, because the formalin tends to preserve the tuber and prevent its de- composition. Potatoes which have been subjedl to diseases may be weakened and their vitality impaired. > From data ia Ohio Exp. Sta. Bui. 145, p. 21. CHAPTER VII VARIETIES Selecting a Variety. — For general farming it is advisable to grow only a few varieties. Most success- ful growers seldom have half a dozen growing for mar- keting, and usuall}" one is selecfted as more suitable than the rest. The beginner is advised to seledt a variety from the more thoroughly tested kinds that have done well in his immediate vicinity and on his type of soil. The .seed should be obtained from a reliable grower or a responsible seedsman. The importance of growing the best varieties cannot be too .strongly emphasized. To man}- a potato is a potato, and any- thing is used for .seed. Such haphazard methods cannot survive. Potatoes are grown for human con- sumption, and the public taste mu.st be considered. Good qualit}' and good yield are required. In .some localities good qualit}- potatoes appear to be grown in .spite of adver.se conditions, but not all of the crop can be produced in this way. Some of the points to consider in .sele(5ling the variety are : 1 . Good cooking quality and flavor. This is parth' influenced by the soil, season, ability to mature before frost, etc. 2. The yield. The late maturing varieties usually yield heavier than the early varieties. Yield is influenced, among other things, by the adapta- bility of the variety to the district and soil. 70 VARIETIES 71 3. Ability to resist diseases. The potato is so sub- je(5l to disease that this is now of prime impor- tance in a variety in the Eastern States, although not so important in parts of the Trans-Missis- sippi area. 4. The color of the skin a7id tuber. In the Eastern States red varieties are not in favor at present, a white-fleshed and white-skinned tuber being preferred. In the South red-skinned varieties are sought.' 5. The 7iat7cre of the skin. A netted, or rough, skin is preferred. 6. The shape. Some markets discriminate in favor of a particular shape, the flat-round and oval generally being popular shapes. 7. TJie depth and frequency of eyes. Potatoes with deep and numerous eyes are not economical in preparation for cooking. 8. The time of maturity . This is essential to know before planting, in order to facilitate the dis- tribution of farm work and determine whether it is likely- to mature in the locality. 9. The haiclni. 10. The leaf. 11. The vigor of the variety. This is important, although it is of equal importance to obtain a vigorous strain of a variety' , as wide variations are noted in the same variety. 12. Te7idency to make second growth. ' Tex. Bui. 71, p. 9. 72 THE POTATO 13. Truaicss to lypc. It is essential that the seed be as represented. As none but an expert can tell the different varieties apart, seed should be obtained from a reliable grower or a responsible seedsman. I, Cooking quality and flavor are two of the facftors which determine culinary value. They are distindt. Cooking quality is recognized in a boiled potato hy mealiness or soggi- FIG. iS — SECTION OF A POTATO OF ^. . I'ooR COOKING QUALITY "^ss. 1 liis appcars P— :E;nvelope, or Periderm, consisting of an tO depend Upon the inner and outer layer. /'•^-Pigment layer, physiological StrUC- where coloring-matter of the skin is found. ^ -^ ^ iJ.C— External Cortical, or Cambium layer, tUrC of the tubcr, and usually poor in starch. /.C-Internal Cor- is not nCCeSSarilv COn- tical, or Cambium layer, rich in starch. E.A/ . —External Medullary layer, rich in starch, ncdlcd witll chcmical /.^/-Internal Medullary layer, or pith, or compositioil (Ficrs. water-core, poor in starch. V es- • The objectionable features of this tuber are 18, I9). A pOtatO large pith area and lack of uniformity in sllOwiug UnifomutV cellular structure. Each layer is readily rec- . ... ognized, and each one varies in the amount of IW the distribution of time required for cooking; hence, it is of poor starcll ill the VarioUS cooking quality. (Compare with Fig. 19.) layers may be con- sidered to be of better quality than one not showing this uniformity. Immature potatoes tend to be soggy VARIETlEvS 73 when cooked. Menliiiess is due to the union of tlie starch grains in a cell into one mass, and the rup- ture of the cell walls during cook- ing. Sogginess occurs when the cell walls retain their form. Opin- ions differ as to what constitutes good cooking quality. Amer- icans like a white, mealy, or floury, potato. The French prefer a yellow, soggy potato which re- tains its shape when boiled. Good cooking quality can be de- termined by cook- ing. The common method is to take a sample and steam or boil some of the potatoes. When cooked the potato should be dry and floury, free from wetness, and readily break to pieces on slight pressure, or be readily reduced to a coarse meal free from hard lumps. The particles should glisten as though crystalline, and the potato should have a white color, which is retained when cold. Potatoes which FIG. 19 — SECTION OF A POTATO OF GOOD COOKING QUALITY (Compare with Fig. 18.) The desirable features of this tuber are well- netted skin, showing maturity; large Internal Cortical (I.C.}and External Medullary (^.xl/.) layers, which are rich in starch ; small pith area (/..!/.), with marked uniformity in cellu- lar structure. The different layers nearly ap- proach each other in appearance, and cook uniformly. 74 1*HE POTATO are yellow when cooked, or turn dark or black, are not considered of good quality, even if the flavor is good, and can be sold only to a low-class trade. Tubers must not be hollow in the center, as this gives rise to a hard, dark-colored core, which is decidedly objectionable if potatoes are to be mashed. Some varieties will cook better if they have been kept ; they are, in other words, for spring use. Thus, in New York, Carman No. 3, White Star, and Doe's Pride come in this catego^3^ The flavor should be mild, and free from earthiness. 2. The yield. The average jdeld of potatoes from one plant in the United States is about half a pound. Having weighed the yield of hundreds of potato plants during the past year, we find that in the case of Early Ohio one plant ^aelded three tubers weighing half an ounce, while another yielded thirteen tubers weighing two and a half pounds. The latter yield is eighty times the former. In late varieties plants yield- ing four pounds of tubers were found. In some of the recent English productions whole plats would average six pounds of tubers per plant, while individual plants have yielded over twenty pounds of potatoes, as many as 150 potatoes being set on one plant.' These fadls emphasize the value of the farmer sele<5ling seed him- self and eliminating the poor plants. All the tubers from the best plants should be sav^ed and planted sep- arately to produce the seed for the following year. The expenses of growing a poor and a heavy crop vary little. The only additional cost of the latter is 1 Gardener's Chronicle, Oct. 15, 1904, pp. 276-278. I VARIETIES 75 a little more for digging. The variety controls the yield to a large extent, and there is much more like- lihood of obtaining a 300-bushel crop from a variety capable of yielding 600 than from one whose maxi- mum yield is 300 bushels. This fadl is realized, and the high prices paid in recent j^ears in Great Britain for seed potatoes of good quality, heavy yield- ing, and disease-resisting varieties are legitimate and proper recompense to the men who have the skill to breed such. These new varieties are profitable to grow because there is an assurance that the crop will yield well, and that it will keep well; hence there is an opportunity to hold it until it can be sold at a profit. These farmers realize that the best is none too good, and that it is useless handling varieties that are out of date. The potato grower of Great Britain and Europe must be up to date if he is to stay in the business. High-priced seed receives more care in storage and is handled more intelligently, the seed-bed is better pre- pared, and the result is better farming. The farmer who grows such crops is a more thoughtful and better business man, as slovenly methods have to be aban- doned. Yield is influenced by the size and number of tubers at a root. Uniformity and good size are desired. Potatoes vary in size from almost nil to six pounds each or more. In Doe's Pride one plant set 21 tubers, varying in size between i-io ounce and 6}4. ounces; in other words, one potato was 65 times larger than the other. In the East potatoes over 8 ounces in weight are large. Medium-sized tubers of merchant- able value vary between four and eight ounces. Sec- 76 THE POTATO onds between two and fonr onnces, and tubers less than this weight, arc hardly worth picking up. 3. Ability to irsist diseases. No varieties can be termed ' ' disease proof, ' ' but many varieties are better disease-resisters than others. Stuart, of New Hamp- .shire, found that the variety Hulett's Rust Proof was the only one that was disease-resistant out of several varieties, although the varieties Dakota Red, Green Mountain, New Queen, and Enormous showed some resistance. Hulett's Rust Proof falls below the re- quirements in other respedts and is of little value, and in Minnesota has been found to be subjedl to disease. At Ontario Agricultural College, Carman No. 3 and Stray Beauty resisted disease well. At Minnesota Experiment Station, Rural New Yorker and Sir Wal- ter Raleigh showed some resistance." 4. The color of the skiii and tuber. ]\Iany of the colored-skinned varieties of potatoes, and those show- ing a blush of pink — as, the Beaut}' of Hebron, Early Rose, etc. — belong to a t3-pe which have white blooms. They are generally early maturing, rather liable to dis- ease, and of good quality, according to the American standard. The colored-skinned early varieties are gen- erall}' more readily sold than the late ones, although in some distridts colored-skinned potatoes are not ob- jedted to on the market. All colored-skinned potatoes are not deficient in vigor. Some are among the best disease-resisting and best-flavored varieties, but the red color of some weak varieties has rendered some growers skeptical of all. 1 Minn. Bui. 87, p. 2. • Minn. Bui. 87, p. la 78 THE POTATO 5. The nature of the skin. The skin may be thick, medium, or thin. Some, growers claim that thick- skinned varieties are of better quality than thin-skinned ones, but such correlation does not always exist. Potatoes grown on sandy soils usually have smoother skins than those grown on heavy loams. Some va- rieties develop a netted, or rough, skin as they mature in storage, although such ma}- not be apparent at harvest-time. The rough, or netted, skin in these cases appears to denote maturity, and this may account for the common idea that a rough-skinned potato is of good quality. The size and type of netting (Fig. 20) varies with the variety, and the conditions under which it is grown. 6. The shape. Most of the recent introductions, exclusive of the Early Rose type, have had a tendenc}' to partake of the flat-round or oval (Fig. 21). These shapes have been sought because such potatoes appear to be of better quality consistent with an economical shape and shallow ej-es. The probable explanation is that in a flat-round or thinnish potato there is a greater surface in proportion to the bulk. The greater the surface the larger the percentage of the tuber taken up in the cortical layer and outer medullary layer (Fig. 18). These are the starch-bearing areas, and as the}' are increased the inner medullary layer, or pith, which has little starch, is diminished, thus rendering the potato more uniform. Whatever shape is desired can be be obtained, but a potato should be true to shape. The tendency of a tuber to become pointed or drawn out at the tip or butt end, especially if the variety is a flat-round or round, indicates lack of vigor (Fig. 21). VARIETIKS 79 7, Depth and frequency of eyes. Deep eyes (Fig. 21), to some extent, are regarded as associated with robust- FIG. 21 — THREE FAVORITE SHAPES OF POTATOES (Upper row, the broad surface ; lower row, the narrow surface.) Beginning on the right, the small one is a flat-round; the center one, kid- ney; the largest one, on the left, elongated oval. Notice the shallow, wide eyes on the latter; they are the most desirable. The eyes of the flat-round are too deep. iiess and, frequently, coarseness. They are wasteful in peeling. Deep eyes tend to hold moisture, which hastens decay when the potatoes are stored. 8. Time of maturity. In the Northern States pota- 8o THE POTATO toes are classified into early, medium or second early, and late varieties, according to the time the}^ take to reach maturity. Early varieties may mature in 70 to >^ t^ M - 1 UliMlllBm ra ^ W^k '—IM ^pi * ^:'^'-,l ' ^ \ ** .-'1 . ^f*^-^ FIG. 22 — THE IMPORTANCE OF HAVING UPRIGHT HAULM AND PRESERVING THE FOLIAGE IS NOT SUFFICIENTLY ATPRECIATKI) Plant photographed early in September, 1904, when many others near were dead (C. U. Farm). Upright haulm facilitates late cultivation and spray- ing. The foliage dries quickly, and then is not so favorable for the growth of spores of rot. 90 days after planting ; second earlies, in 90 to 1 30 days, while late varieties may continue to grow for 200 days. 9. T/ic haulm. The haulm and leaf are receiving more attention to-daj' than formerly. The size of haulm has an influence upon the distance apart of planting. L,arge haulm is more trouble to spray, re- VARIETIES 8l quiring more solution, and it is always lying over the ground when the last spraying ought to be given, and is in the way at lifting-time, whether the potatoes are raised by hand or digger. Modern breeders aim to produce a short haulmed, upright, heavil}' leaved top, because the upright habit of growth (Fig. 22) is more likely to keep clear of disease than a spreading habit, owing to water being shed from the former more read- ily than from the latter, and not offering a foothold to the disease spores (Fig. 37). Plants whose branches lie on the ground are more liable to disease because they cover a greater area, their leaves, touching the ground, are almost alwaj's damp from contadl with it, and sun and wind cannot so readily reach them. Very tall haulmed varieties are readily beaten down b}- storm and wind, and in this .state thej' cannot dry so readily; hence, the}' fall in a clammy mass, very favor- able for the growth of disease spores. Varieties with strong, hardy haulm suffer less from spring frosts. Late varieties usually have taller haulm than first early varieties. Some varieties make their heaviest growth of foliage late in the season, and in this way are not .so subject to attacks of early blight. 10. The leaf. The British disease-resisting varieties have hard, thick leaves. Whether the thickness of the leaf is an important fadlor in their resistance to rot {Phy- tophthora infestans) is not determined. The fadl that spraying the upper surface of the leaf tends to prevent blight would seem to show that access to the inside of the leaf is obtained by growth through the cell walls as well as through the stomata, on its under surface. If this be true, then the thickening and hardening 82 THE POTATO of the cuticle and the pahsade cells (Fig. 34), or thick cells on the upper surface of the leaf, will no doubt prevent many spores from reaching the inside cells of the leaf. They may germinate on the surface, but not enter, unless they find some place where the leaf has been injured. The pundlures of the flea- beetles are, on this account, of great importance, as they furnish an entrance to the inner cells (Fig. 40). N. A. Cobb, of Australia, has shown that in the case of wheat the varieties most resistant to rust {Puc- cinia graviinis ■Oi.wA P. ritbigo vera), none being abso- lutely resistant, have narrow, stiff, upright foliage, while those most liable to attacks have broad, flabby, and pendant foliage. In the plants resistant to rust the cuticle of the leaf is much thicker than in the others, and is so thick that the rust spores, when they germinate on the outside of the leaf, cannot penetrate it, or if they do succeed in entering the leaf through stomata, the threadlike growths of the parasite cannot rupture the cuticle wall to frudtify ; and, further, some wheats have stomata so narrow and are so well cov- ered with wax that the germinating threads of the rust spore fail to enter every time. These circum- stances seem to support the claim that the tough, thick- walled, hard, dry leaf is the one to sele(5l for disease- resistant powers. It has been observed that plants of the potato family having this type of leaf are fairly free from fungus leaf diseases. It is essential that the leaves of the potato be abundant to insure a good yield. II. The vigor of the variety. Vigor is the power stored in a plant which enables it to overcome difficul- ties at different periods of growth. A variety must VARIETIES 83 have vigor. If not, it raaj- fail to establish itself dur- ing the earh- part of its career, being a sh}' budder ; it ma}- be readily injured by frost, heat or cold, drouth or a wet period, and, having little recuperative power, will give small returns for the labor bestowed upon it. If it survives to tuber-formation time it will probably fail then. Plants or varieties showing lack of vigor must be discarded. Some varieties have short staying power; they appear to be vigorous for one or two years, and then suddenly collapse. Others have great staying power — as. Early Rose, which has been prominent for over forty years. The .statement is sometimes made that modern vari- eties are not so long-lived as their ancestors — that they are deficient in staying power. If the statement were true, it might be explained by .saying that new vari- eties are produced more frequently, and that on account of their heavier yielding power or better quality they displace the old ones. The facfts seem to show that modern potato breeders have more than maintained vigor and staying power. Hays, of Minnesota, and others, place the life of a good modern variety at about thirty years. This .seems to be accepted by many, both here and abroad. Dr. Hunter, of England, in his " Geological Essaj's," ' writing about one hundred years ago, states ' ' that varieties continue in vigor about fourteen years, after which the produce gradually dechnes." Shirreff and T. A. Knight held similar views ; the latter wrote " that ' ' not a single healthy 1 "Geological Essays," ICxp. if. p. M^- 2 Hort. Trans., Vol. I., and Miller's " Gardeners' Dictionary," ed. 1S07, "Potatoes." 84 THE POTATO plant of any sort of potato that yields berries, and which was in culture twenty years ago, can now be produced." So late as 1838 this idea was accepted by the horticulturists of England.' It is interesting to note that the average yield of potatoes in England a hundred years ago is stated to vary between 185 and 300 bushels, and sometimes 440 bushels, per acre. The average yield to-day is about 230 bushels, but some growers produce 750 bushels per acre frequently. The average improvement in the quality of the tubers is greater than the average improvement in yield. Formerly the potatoes were grown largely for stock, and were of poor flavor and bad cooking quality. Some new varieties make vigorous growth, and, be- coming bark-bound, the skin cracks. Such varieties are regarded as of coarse and inferior quality, and lack- ing in appearance. This characfler may be eliminated by judicious selecftion. Deficiency in vigor is indi- cated by the formation of misshapen tubers drawn out at either end, the presence of second growth, weak buds, lack of uniformity in texture — as, hardness at the ends of the tubers when cut, especially brittleness of texture. Tubers showing any such charadleristics should not be planted. When potatoes are planted 15 inches apart in 36- inch rows, there are 11,616 plants per acre. If each plant had sufficient vigor to yield three tubers, each weighing half a pound, or four weighing six ounces each, a yield of 290 bushels of salable potatoes per acre is assured. No one can. afford to use seed of less vigor than this. ' Dou's" Gardeucrs' Dictiouary," 1838, Vol. IV., pp. 400-406. VARIETIES 85 12. Tendency /o make second growth. Second growth (Fig. 38) is most prevalent in a season when drouth is followed by a wet period. The drouth checks the development of the tubers, causing them to begin to mature, while the subsequent wet period restarts growth. If one variety or a plant does not show any such abnormal growth, it is regarded as being more vigorous; hence, other things being equal, such should be used for seed, and all showing second growth should be rejected. Abnormalities in shape may be due to contadt with stones or hard lumps. 13. Trneness to type. This may be viewed as em- bracing several considerations. In new varieties there is always more or less tendency to lose the features for which the variety has been seledled. The type is then said to be insufficienth' fixed, and often those which depart from the type degenerate. In such cases selec- tion must be continued. Many varieties are deliberately or unintentionally sold for something else. Mixtures of varieties are sold as one. Good varieties are often renamed and sold by unscrupulous seedsman and others as some- thing new. There is considerable duplication of varieties of potatoes;' thus. Brooks, of Massachusetts,'' believes, after growing the following varieties, that King of the Earliest and Early Ohio, Salzer's Earliest and Bliss Triumph, Mills' Banner and Livingston Banner are identical, and that White Beauty and Cambridge Russet differ but slightly. Mills' Mortgage Lifter is often sold as Burpee's Extra Early. Some dealers » Wyo. Bui. 32, p. 65. « Hatch (Mass.) Sta. Report, 1899, p. 81. 86 THg POTATO have been known to deliberately rename a well-known variety and sell it as their own, and as a new and heavy yielding variety. Dakota Red is sold for Bliss Triumph, although in- ferior in quality. The above is not a complete list, but will show that this state of affairs exists, and empha- sizes the importance of dealing with a firm who have a reputation to lose. Testing Varieties. — It is advisable to secure copies of experiment-station literature and papers in which variety trials are reported. The best variety for one soil is not the best for another. The only way to have the best is to make a trial with small quanti- ties of different varieties. Secure seven to ten pounds of seed of each new variety, and plant, say, three rows of each on a piece of land as uniform as obtainable, using a standard variety, called A, as a check. If we take B, C, D, E as four untried varieties, buy the seed in the fall, hold it all, including the A seed, under simi- lar conditions, and plant under similar conditions in the following order: A, B, C, A, V, E, A. Treat all plats alike in every respect, dig when ripe, and weigh the crop. If the A plats yield approximately the same, then the dedudlion is that the soil conditions are fairly uniform. If not, compare the yield of each plat with the yield of the A plat nearest to it. Conducft the trial for three years. I find that the second and third years' results are better than the first, as the conditions are more uniform, although if a variety is a long way ahead the first year and shows up well in other ways, I would increase the area under it at once. VARIETIES 87 Relationship of Variety to Soil.— Disappointment and loss arc often the result of not knowing and study- ing the environment best suited to a variety. Each variet}^ and probably each individual in a variety to a lesser degree, has its idiosyncrasies, and, to succeed, these must be recognized and catered to. The failures in potato-growing deser\'e more attention. The suc- cesses take care of themselves. The careful grower takes note of the failure and the success. Both have a cause or causes, and the climatology and charadler of the soil may be among them. Some varieties do better on a heavy loam than on a sandy loam, probably be- cause the former is cooler, owing to its greater moisture content, and under such conditions these varieties give a higher return of starch per acre and are of better qual- ity. Other varieties, as those inclined to be coarse and rough, do better on sandy loams. In this class are Eureka and Uncle Sam. Some require a rich loam soil — as. Early Ohio, Bovee, Early Har\'est, Early Michigan. T. L. Wat- son,' of Virginia, also noted that some varieties want more plant-food than others, other conditions being the same. Others are more cosmopolitan — as, Car- man No. 3, Early Rose. The Most Popular Varieties. — With the obje(ft of ascertaining the best variety as determined by jaeld in different places, a letter was addressed to the director of each experiment station and to some grow- ers; 49 replies were received; 28 men mentioned vari- eties which had yielded or appeared to be best in their • Va. Bui. 56, p. 144. 88 I'HE POTATO districfts. In all 59 varieties were mentioned. Tabu- lating the data presented, we find that 21 of these varieties were mentioned twice or more. In the South- ern and vSouthern Trans-Mississippi States all vari- eties mature about the same t ime and may be classed as earlies, and early maturing varieties are usually planted. Of these and the early varieties, as grown in the North , Bliss Triumph and Early Ohio are the most popular with ten votes each; Six Weeks Market re- ceived five; Early Rose, four ; Burpee's Extra Early andBovee, three each; while Beauty of Hebron, Early Fortune, Eureka, Irish Cobbler, Michigan, and Polaris had two each. Among late varieties, Green Mountain leads wnth eight votes, Carman No, 3 had five, Rural New Yorker and Sir Walter Raleigh had four each, and Burbank, Carman No. i, Vermont Gold Coin, Rural New Yorker No. 2, and Freeman had two each. Although the above method of determi- nation maj^ not be absolutely correal, undoubtedly the varieties mentioned are among the favorites. Station Leading Varieties 1. Alabam.\, Tuskegee . Early — Bliss Triumph. Medium — Early Rose. Late — Peerless, 2. Alabama, Auburn . . Triumph, 3. Arizona Burpee's Extra Early, Triumph, Early Rose. 4. Arkansas Red Bliss. Ohio, Michigan, Six Weeks, Crown Jewel. 5. California .... Burbank, 6. Canada, Ontario . . Extra Early — Pinkeye, Stray Beauty, Early Ohio. Medium — Burpee's Extra Early, Rose of the North, Late — Empire State, American Wonder. VARIKTIES 89 Station 7. Colorado . 8. Connecticut . . 9. Illinois . . ■ 10. Iowa 11. Kansas . . . . 12. G. L. Foss, Fort Fairfield, Me. 13. Maryland . . 14. Massachusetts 15. Montana .... 16. Nebraska, Bui. So . 17. New Hampshire 18. New York, Cornell . 19. New York, Geneva Leading Varieties Medium — Queen of the Valley, Rose Seedling. Late — Pearl. Rural No. 2. Late — Green Mountain, Car- man No. 3, Rural New Yorker. Early — Early Ohio. Vermont Gold Coin. Early — Six Weeks. Medium — Early Ohio. Early — Early Ohio. Medium — Burpee's Extra Early. Late — Green Mountain. Late — McCormick. Beauty of Hebron, Early Rose, Early Andees, Early Dawn, Triumph, Salzer's Earliest, I.X.L., Steuben, Early Nancy, Million Dollar. Early — Six Weeks Market, Early Ohio. Medium — White Ohio, Rural New Yorker. Late — Freeman, White Main. Early — Early Ohio. Late — Rural New Yorker. Late — Green Mountain, Wash- ington. Early — Early Ohio, Bovee. Late — Green Mountain, Carman No. 3, Sir Walter Raleigh. Early — Michigan, Early Trum- bull. Late — Carman No. 3, Uncle Sam, Whiton's White Mam- moth, Sir Walter Raleigh. 90 THE POTATO Station i Ca. I!ul. 29, p. 30,). Tex. liul. 71, p. 7. ° Pa. D. A. Report, 1902, p, 722. " Ca. Bui. 29, p. 305. ' Out. Agr. Coll. l'"ainis Report, 1894, p. 98. PLANTING 95 One inch deep were formed 2.3 inches below the surface ; Three inches deep were formed 2.9 inches below the surface; Five inches deep were formed 4.1 inches below the surface; Seven inches deep were formed 6 inches below the surface. It was observed that those planted i inch deep fur- nished many sunburned potatoes, while those planted deeper had almost none. Gilmore, of Cornell, ob- tained somewhat similar results during the year 1904. GoflF,' of Wisconsin, planted the Burbank variety at different depths, and found that shallow planting in- sured greater germination and more tubers per hill, but that they were nearer the surface and had more ex- posed tubers. TABLE X Depth of Planting Hills Ger- minating Tubers Protruding from 'Soil Average Number of Tubers per Hill Average Weight of Tubers per Hill A verage Depth to Deepest Tuber 2 4 6 Per cent. 100 96 88 Per cent. 8.4 ,S 6.6 5-4 3-2 Pounds •58 .62 •35 hi dies 2.5 3-5 50 The Canadian Experiment Farms^ report, as the re- sult of four 3'ears' trials, that with tubers planted i inch to 8 inches deep, where the sets were planted less than 4 inches deep, nearly all the tubers were formed between that depth and the surface, and when plant- ed deeper than 4 inches most of them formed within 4 inches of the surface. The deduction made from these results was that the potatoes developed in the surface 1 wis. Report, 1897, p. 306. ^ Can. Exp. Kariu.s Report, 1901, p. 117. 96 THE POTATO 4 inches of soil because it was warmer than the 3 or 4 inches lower down. Influence of Depth on Quality. — On a sandy loam, under New York conditions, potatoes grown about 4 inches deep are generall}' of better quality than those grown nearer the surface. In other places, those grown at even greater depths have been observed to be of better qualit)-; thus, at North Dakota Station,' potatoes 5 to 6 inches deep were better than those 3 or 4 inches deep in this respecft. Date of Planting. — As would be expelled, the dates of planting potatoes vary widely, and the only way to deal with the question is to give the common dates for a certain locality. The reader is advised to inquire of the growers in the locality the date con- sidered best, and, as a general rule, it is wise to plant early for the distri(ft. Canadian experimenters^ report, after four years' trial, that the end of May is the best time, and that June 24 is usually found to be the latest date for planting potatoes to produce satisfadlor}^ re- turns, although in 1 900 a good crop was obtained from a planting on July 7. In Wisconsin the middle to the end of May, and in Maine late in May and early in June, are considered best. At Cornell University, in 1901, potatoes planted May 16 yielded 250 bushels per acre, while those planted June 12 and 17 jdelded 162 and 197 bushels respedlively. In Oklahoma^ potatoes planted March 14 came up and matured as early as those planted February 27. The early potato crop of Vir- ginia is usually planted during February and March, ' N. I). Report, 1901, p. y6. * Can. Exp Farm Report, 1901, p. 119. 3 Okla. Bul. 52, p. 9. PLANTING 97 and the second crop about August i. In latitude 33° the dates are about two weeks later. Influence of Late and Early Planting. — The practice of growing a late crop of potatoes has spread northward, and in parts of New York it is custom- ary to plant potatoes late in the season after another crop, as peas, has been removed. The pracftice seems commendable, but discouraging reports from the potato salesmen in regard to the quality of these potatoes led the Cornell University' Experiment Station to under- take investigations to determine, if possible, the fadls. Mr. Gilmore, who is conducting this investigation, has furnished the first ^-ears' results, but these are in- sufficient to permit of dedudtions being made. TABLE XI VARIETY Date of Planting Dale of Ufling Tolal Ash Dry in Dry Mat'ter Matter Protein in Dry Matter Starch in Dry Matter Green Mountaiu.. Green Mountain.. Doe's Pride Doe's Pride Mav 7 July 6 Mav 7 July 6 Sept. II Oct. 22 Oct. 20 Oct. 22 Per ct. 22.9 i3.i 21.75 19-05 Per ct. 5-56 5 39 5-10 Per. cl. 11.86 10-35 12. II Per ct. 77-38 72-43 74.28 71.14 In both ca.ses the late-plantetl potatoes contained less dry matter and less starch, or, in other words, were more watery, and appeared to be immature. Similar results were obtained during the present year (1904). Methods of Planting. — The former method and one .still quite common is to plant potatoes by hand. A furrow is thrown out by a common plow, or a shovel-plow, and, if applied, the fertilizers, and in fcl 3 PLANTING 99 some cases the manure, are placed in the furrow, the potatoes dropped in, and then covered by the plow. Generally speaking, the furrows should be thrown out so that the potatoes will be four inches below ground when the surface is level. The furrows are made the B Courtesy Cornell University. FIG. 25 — PLANTING BY HAND A — Tuber planted by hand in furrow opened with a shovel or double mold- board plow. J} — The potatoes covered with shovel plow. C — X,and har- rowed level a few days after planting, to destroy weeds, leaving the potatoes four to five inches deep. Few farmers plant at this depth, even when they mean to do so. required distance apart. It has been deemed necessary to place the potato in position, and fix it so that it will not move when covered. In England this is done by requiring the planters to press it down by hand, and in this country the potatoes are often stepped on for the same reason. The stepping on them may injure lOO THE POTATO buds, and hence is detrimental. The rows should be made straight, and care should always be taken to have the potatoes planted in a straight line and at a uniform distance apart. The former facilitates in- tertillage to such an extent that it is worthy of atten- tion. On a dry, hot day it is inadvisable to open the FIG. 26 — SECTIONAL VIEW OK ASPINWALL PLANTER rows much ahead of the planters, and the seed should be covered as soon as possible to prevent loss of mois- ture. Frequently the rows plowed out before the noon meal hour and left open for this time show the injuri- ous eifedl of the loss of moisture, especially if the seed is cut. Wherever hand-planting is done and the tubers are not sprouted, the hand-planters, which are l^I^ANTlNCr lOI somewhat like hand corn-plauters, may be used with profit. They cost $1. GO to $1.50, and it is claimed that an adlive man can plant at least one acre per day. Every large grower of potatoes requires a horse- planter. From six to eight acres will warrant the use of such a machine, and it may be made to pa}^ for itself in a short time by hiring it out — preferably with FIG. 27 — ASPIXWAI.L POTATO I'LANTKR (siDE VIEW) a man to work it. Some planters require one man, others two men, to work them; the latter generally do the best work, although good work is done by the former. Two systems of mechanism are emplo5"ed — the picker and the platform. In some planters the tubers are fed from the hopper onto pickers, or spikes, which projedt from a revolving vertical disk. The disk carries them round to the top of a delivery pipe, where they are knocked off, or fall off, going down the pipe 102 thi; potato to the ground. This sj-stem, or a luodificatioii of it, is used in the Aspinwall (Figs. 26-27), the Deere, and the the Eureka planters. Trials with a planter of this type showed that, with small whole. seed and well-prepared ground, this machine will work up to its guarantee of 95 per cent. ; that is, it will not .skip more than 5 places in 100. With longer cut seed and rougher land, espe- FIG. 28 — THE ROBBINS IMPROVED PLANTER cially if slightly hilly, it will miss up to 20 in 100. If these misses were distributed it would not be so serious, but often 5 or 6 occur at a stretch. If the seed is cut long and thin, the pickers may take hold of two pieces instead of one. This happens frequently — often up to 20 per cent. These machines open the furrow, distribute the fertillizer, plant the potato, and cover. The latter operation is usually performed by revolving concave disks. The distance apart of the tubers is regulated by adding or removing the pickers. The higher-priced PLANTING 103 machines are stronger made than the lower-priced, and, in some cases the fertilizer attachment is extra. The Robbins improved potato-planter (Fig. 28) is of the platform t}pe. The potatoes are elevated from the hopper by means of a wheel, and are discharged onto a platform which is cleared by several revolving arms (Fig. 29); the mechanism is so timed that a potato FIG. 29 — THE TLATFOKM UF THE ROBBINS IMPROVED PLANTER should fall on the platform between each two arms. Sometimes the elevator comes up empty or brings two pieces up ; in either case it is necessary for the man sit- ting behind to put one piece on the vacant part of the table between the arms or take the extra piece off. In this way the tubers are planted more carefully and regu- larly than most hand work. The amount and distance apart of seed, and the amount of fertilizer sown, are I04 T^HK POTATO regulated by interchangeable sprockets. The various parts of the machine are driven by means of a chain drive. This machine opens the row, distributes the fertilizer in rather a wide stream, plants the potato, and covers it in a satisfadlory manner. Any ordinary required depth can be obtained. It can be used for planting beans, corn, and other crops. With potato- planters three to six acres can be planted per daj^ lyosses of crop due to insufficient seeding cannot be made up during the year. The land requires the same amount of work, and the soil needs moving at digging- time; but there is not the 3neld, and it is an important consideration whether 5 per cent, to 20 per cent, loss of plants per acre is not too high a price for the sake of one man's pay per day. Even with the cheapest " picker ' ' planter, the lower initial cost is not sufficient to recompense the grower for the loss sustained by using it on ten acres when compared with the perfe(5t machine. CHAPTER IX MANAGEMENT OF THE GROWING CROP Cultivation. — Almost invariably judicious cultiva- tion of potato land is profitable. It is secondary to good preparation of the laud. The objedl is not primarily to destroy weeds, although this may be a consideration. To-day intelligent farmers till to in- crease yield. Tillage is manuring. No better illustra- tions of this fadl can be found than the tillage experi- ments of Roberts and others at Cornell University.' In these trials potatoes were grown several years in suc- cession, without manures or fertilizers, upon the same land, and yields varying from 300 to 350 bushels per acre, or three to four times the average yield of the State, were secured for .several years. This illustrates the value of tillage, but in its entirety is not necessarily a good pra^fice. Tillage destroys humus, and as this is one of the most essential constituents of a good potato soil, a rotation of crops is advised to aid in maintaining the supply. Tillage may be overdone, especially deep tillage in dry weather. During such a time only sufficient shallow tillage should be given to maintain a mulch. At Cornell from seven to nine cultivations seemed to be most profitable, or about every seven to ten days until the potato-vines meet in the rows. Tillage must be given when necessary. The right number of cultiva- 1 (N. Y.) Coniell Hul. 140, pp. 389-390; 191, p. 192. 105 I06 THE POTATO tions will vary with each year aud the class of soil. The Ohio Experiment Station' found that thorough culture encouraged vigorous growth and aided the plants to resist fungous troubles. The objedls of tillage, then, are : 1. To increase the crop-producing power, presum- ably by : (a) Liberating plant-food. (/^) Maintaining good texture. (c) Conserving moisture b}^ the aid of a soil mulch. («') Pulverizing the ground, so that every shower of rain can enter the soil and not flow off, transporting the fine soil particles. 2. To keep weeds in check. System of Culture. — //z7/s. — Generally hills — that is, where potatoes are planted in checks — are unprofit- able because there are not enough plants per acre and the yield is too low; hence the system is little used un- less a piece of land is verj^ weed5\ Dri/h. — By " drills" it is understood that the soil is thrown toward the potatoes, leaving a depression or furrow between the rows. This system is used for irrigation, when the water flows between the rows. It is also pradticed in humid climates, where the tempera- ture does not go high — as. Northern England, Scot- land, etc. — and on wet soils and in wet seasons. Often the "furrowing" injures roots and reduces the yield, but many growers claim that the ease with which the potatoes can be dug from drills compensates for any loss in yield. The objedlion to level culture is that » Ohio Bui. 76, p. 47. MANAGEMENT OF THE GROWING CROP 107 difficult}' is experienced in securing machiner)- which will dig all the tubers. Level Culture. — In this system the potatoes must be planted a little deeper than in the case of the other two, to reduce the percentage of sun-burned tubers. This system is advocated throughout most of Eastern North America, as, among other things, the quality of FIG. 30 — HALLECK EXPANSIblE WEEDER the potatoes is better, owing to the ground being cooler. Its use has been found advisable at such various points as Cornell,' Louisiana,' North Caro- lina,' Wisconsin,^ and Arkansas" Experiment Stations, while the Maryland" Station, in a trial lasting six years, found little difference between level and drill culture, but the slight variation was in favor of level culture. Method of Cultivation and Tools Used. — About a week after planting the spike-tooth harrow should be run over the land, preferably in both directions, if a mulch is not made by one harrowing. This destroys ' (N. Y.) Cornell Bui. 140, p. 390; 156, p. 175. ' N. Car. Bui. 85, p. 4; 146, p. 262. ' Ark. Bui. 50, p. 29. 2 l,a. Bui. 22, p. 705. * Wis. Report, 1S99, p. 210. • Md. Bui. 62, p. 204. io8 The potato young weeds and brings more seed up to germinate, which may be killed by another harrowing a week later. When the potatoes appear, the weeder (Fig. 30) will be found the most serviceable implement for holding the weeds in check and maintaining the mulch. It may FIG. 31 — FIVE-TOOTII CULTIVATOR WITH IIILLER ATTACHMENTS Still used by manj' farmers. be driven across the rows after each cultivation until the potatoes are 9 or 10 inches high. As a good horse and man can do twenty acres a da}', it is quite expeditious and generall}^ satisfadlory. Generally speaking, it is advised to cultivate widely and deeply from 4 to 6 inches the first, and, in some cases, the second time after the potatoes appear, then reduce the width and the depth to one inch or so. MANAGEMENT OF THE GROWING CROP 109 The first aud second cultivations may be given with a five-tooth cultivator (Fig. 31), or a sulky cultivator (Fig. 32) may be used. The spring-tooth cultivator (Fig. 33) is found to be a very useful tool for inter- FIG. 32 — A ISKFUL TWO-HORSE CTLTIVATOK A requisite wherever large areas of potatoes are grown. tillage work for the third and .subsequent cultivations, and the spike-tooth expansible cultivator with the shields is an excellent tool for .shallow tillage, as it destroys the small weeds and helps to maintain a soil mulch. no THK POTATO Mulching. — In some distridls good yields have been obtained by mulching the land with straw, shavings, pine straw, or some similar substance, instead of cultivating it. Waugh found that it increased the FIG. 33 — ONE-HORSE STRING-TOOTH CULTIVATOR An excellent tool for the later cultivations. yield in Oklahoma' and similar results were obtained in New Jersey," while in Georgia,' Michigan,' Wis- consin,^ and in my own trials in New York, it was found to be unprofitable, even when the yields obtained were about the same under both conditions. 1 Okla. Bui. 15, p. 32. ' Ga. Bui. 29, p. 348. * Wis. Report, 1899, p. 209. - N. J. Report, 1901, p. 418. * Mich. Bui. 95, pp. 13-16. CHAPTER X OBSTRUCTIONS TO GROWTH AND DEVELOPMENT The obstrucftions to growth may be treated under the following heads: 1 . Season arid Climate. 2. Weeds. 3. Diseases due to parasitic fiuigi and bacteria. 4. Insects. 5 . A rsenical poison ing. I. Influence of Season and Climate. — The in- jurious influence of dry weather at planting-time has already been observed ("Viability," page 66). At the (Hatch)' Massachusetts Experiment Station it was observed that the wet condition of the soil at the time of planting appeared to induce the rotting of the young plants just below ground. The occurrence of several extremely hot sunny days in July, following a long rainy period, caused the plants to wilt from the wet condition of the soil and low vitality. No disease was apparent. Probably these plants showed the injurious results consequent on defedtive respiration due to high temperatures. Frost may cut down early planted potatoes. Tip Burn.'' — This is most common in Norcheastern 1 Mass. (Hatch) Report, 1S9S, p. 52. 2 Ver. Report, 1899, p 151; Bui. 72, p. 10. (N. Y.) Cornell Bui. 113, p. 309. Conn. Report 18 (1894), p. ijj. 112 THE POTATO America. The leaves become brown on the margin and die. It is caused by drought, and is more prevalent on light soils. Irrigation and sele(5lion of vigorous varieties, more care in cultivation, and fertilizing are suggested. At Wisconsin Experiment Station,' Green Mountain, Rural New Yorker No. 2, Everett's Heavy Weight, and Colossal proved most resistant in 1896. Sun Scald. "^ — Its efife(5l is similar to that of tip burn. It is more prevalent in the Southeastern United States, and is often noticed when long-continued damp weather is followed by several hot, bright days. 2. Weeds. — These injure the plant b}- using water and other plant-food, crowding the plant, preventing the free circulation of air, and in these ways reducing the vitality and rendering the potato more subje(5t to disease. 3. Diseases Due to Parasitic Fungi and Bacte- ria.— IvATE Beight or Rot ' { Phytophthora infestans). — There is reason to believe that this disease has existed for ages in the western parts of South America, and was disseminated over Europe a long time before its presence was recognized. It seriously injured the crops of potatoes in the United States and Canada in 1843, and reappeared the following year. In July, 1845, it was first detedled in Europe, in Belgium, and within two months thereafter it was recorded in Eng- land, Ireland, vScotland, France, Germany, Denmark, and Russia. Since that time it has never been entirel)' 1 Wis. Report, 1896, p. 240. - U. S. U. A. Farmers' Bui. 91, p. 10. " (N. Y.) Cornell Bui. 113, pp. 297-302. Vt. Bui. 49, pp. 90, 91; BmI. 72, p. 13. U. S. D. A. Farmers' Bui. 91, p. 8. OBSTRUCTIONS TO DEVELOPMENT II3 absent from the potato crops, although in some years it is not so destrudtive as in others. The disease appears during damp, muggy weather in August and September. It is often noticed as small brownish spots on the lower leaves, which rapidly en- large. In moist weather the edges of these spots, on the under surface of the leaf, appear to be covered with a white downy mildew. In dry weather this may be difficult to detedt. lyater the leaves appear as though burnt, and finally the whole plant, and in some cases the whole field, will become a putrid, offensive mass of decaying stems and leaves. The tubers may be attacked also, and rot in the field or in storage. Sometimes the disease runs a very rapid course, and a field will wilt down in twenty-four to forty-eight hours. Cause.— The cause is a parasitic fungus which com- pletes its hfe history in four or five days or less. The whitish mold is made up of stalks bearing branches (Fig. 34). These bear spore cases (Figs. 34 and 35), which break up to form spores (Fig. 35). These spores send out small tubes (Figs. 35, 36, 37). which enter the potato leaf through a stomata, or breathing pore (Fig. 37), or penetrate the cell wall (Figs. 36, 37). The tubes spread in the walls of the leaf cells (Fig. 34) like mushroom spawn in a mushroom bed, utiliz- ing the plant-food which should go to form tubers. At intervals they send out spore-bearing branches through the stomata (Fig. 34), which perpetuate the trouble. Unless the tubers are well covered with soil, the spores may fall on the ground, and, reaching the tubers, transmit the disease to them. 114 THK POTATO FIG. 34- -SECTION OK A POTATO LEAK (After Marshall Ward) Showing the parts and the threads, or mycelium, of the blight or rot (,Phy- lophthora infestans) a — Epidermis, or outer cells, b — Palisade cells, which aid iu giving rigidity and firmness to the leaf, and in the manufacture of starch and other ingredients, c— Spongy tissue, showing cells and large air spaces between. N. J. Report, 1899, pp. 344-345. 2 n. J. Report, 1S99, p. 329; 1900, p. 417. » (N. Y.) Geneva Bui. 138, p. 631. * (N. Y.) Geneva Bui. 138, p. 629. N. J. Report, 1900, p. 417. 122 THE POTATO less subject to it than those from heavy soils, and the disease spreads most rapidl\' in a damp, warm, and close cellar. 2. Due to bacteria.' The tubers may be wholl}' or partialh- soft, and exhale a disagreeable odor. Butyric acid may be liberated and the destruction of the tubers is slow. Contact with other potatoes should be avoided. If to be u.sed for .seed, in some cases depending on the cause, soaking the tubers in formalin before plant- ing is beneficial. Dry Rot may be the evidence of the presence of one or more of .several troubles.'' 1. Stem rot,' bundle blackening, dry end rot, is be- lieved to be due to a fungus {Fiisariuvi oxysporum) ; the leaves curl, and the foliage wilts and dies. The tubers show brown or blackened bundles at the stem end under an appareuth' sound .skin. The disease spreads rapidly in storage, especially if the rooms are warm. Some investigators advise that diseased tubers should not be fed to .stock, thrown on the manure-pile, or planted, and that all such potatoes should be de- stroyed at harvest-time or as .soon as discovered. No remedy is known. 2. Due to badleria. The tubers may be free from odor, moderately firm, but more or less soft in .spots, .showing in places a loose skin, which 3 ields to the fin- ger, and under which are white, gray, or brownish blotches. vSoaking unaffe(fted tubers in formalin before planting is suggested. 1 l\\. Bui. 40, p. J40. 2 111. Bui. 40, p. 139. Tex. Bui. 42, p. 926. = U. S. D. A. Bureau of Plant Industry Bui. 55. (N. Y.) Geneva Bui. loi, pp. S3, 84; Bui. 138, pp. 632, 634. OBSTRT'CTIOXS TO DEVELOPMENT 127, 4. Insects. — Till'; Flka-beetle {Orpidodcra {Epi- trix) cucumcris) (Fig. 39). — These small insecfls often cause more loss than the potato beetles. They perforate the leaves (Fig. 40) during a critical FIG. 39 THE CUCUMBER FLEA-BEETLE (Crepidodcra {Epitrix) cjtciimeris) (After Chittenden) Highly magnified. The insect is barely one-eighth inch long. , The damage done by this in- , sect is considerably under- estimated. period of the plant's life. The holes pro- duced are used 05 tne ^j^, ^^ — leaflet of potato, show- spores of both early ixg over a hundred holes made and late blight for by flea-beetles entrance into the leaf. The ease with which this damage might be overlooked is evident. These holes make Arsenical poisoning is suitable avenues for the entrance of spores USUallv first noticed of disease, and pave the waj' for the rapid destruction of the plant. on the margins of the.se holes. At no time in their life history can these insedls be readily destroyed. They di.slike Bordeaux 124 THE POTATO mixture ; lieuce, the only kuwwn means of reducing their ravages is to spray the plants with this material. NUMBER UK FLKA-BliKTl.K I'UNCTUKES ]N 50 I.KAKLKTS FROM 12 ADJACENT ROWS ' Ptinctures Row I. — Sprayed with very weak Bordeaux mixture . 1,794 Row 2. — Sprayed with very weak Bordeaux mixture and soap 1,071 Row 3. — Not Sprayed 2,511 Row 4. — Sprayed with strong Bordeaux mixture . . 1,194 Row 5. — Sprayed with strong Bordeaux mixture and soap 1,090 Row 6. — Sprayed with weak Bordeaux mixture . . . i,29J Row 7. — Sprayed with weak Bordeaux mixture and soap 901 Row 8. — Not sprayed 2,287 The grubs of the flea-beetle infest the tubers and roots of potatoes, doing some damage and causing the trouble known as "pimply potatoes."^ In the Pacific Coast the flea-beetles {Epitrix subcri- nita, L,ec., and E. Jiirtipcnnis, Mels.) sometimes reduce the yield 50 per cent, by their ravages. As they are leaf-eaters, the foliage should be sprayed or dusted with an arsenical poison. One pound of Paris green to 150 gallons of water per acre is suggested," but it is better to apply the Paris green in Bordeaux mixture. The Potato Beetle, Colorado Potato Beetle, OR Potato Bug i^Doryphora decenilineata). — Until 1850 this inse(5l was confined to Mexico and the Rockies. In 1859 its eastward movement was noted, and it is now well distributed. A related species {D. Jicnda) 1 Vt. Bui. 72, pp. 6-9. "^ (N. Y.) Geneva Bui. 113, pp. 312-317. »Cal. Bui. 135, p. 29. OBSTRUCTIONS TO DEVELOPMENT 1 25 retreated before its advance, and is now more common in the South. In New Mexico' a parasite lives on the eggs and larvae. The eggs are laid on the potato leaves, on which the young "bugs" live, chewing holes in or eating the whole of the leaf. The insedls are most adlive about blossoming- time, and do con- siderable damage if left alone. Modes of Combatting. — The leaf should be thoroughl)'- coated with a poison, generally an arsenical compound being used. The poison should be applied as soon as the "bugs " hatch, because the younger the " bugs " the more easily they are destroyed. Various arsenical compounds are used — as, Paris green, arsenate of lead, and others. "Bugs" objedl to Bordeaux mixture, hence in applying the poison it is found to be good pracftice to apply Bordeaux mixture at the same time. The whole of the plant should be covered, because if badly sprayed the bugs live on the unsprayed foliage. The standard application is ^ to ^ pound of Paris green to 50 gallons of mixture. Generally i pound of Paris green is sufficient per acre, and if it is desired to apply more than 100 gallons, the proportion of Paris green should be varied accordingly. If desired, Paris green may be applied in the dry form bj^ means of a powder gun, the Paris green being mixed with flour, land plaster, etc., as desired. About 50 cents per acre • should cover the cost of one application. The Potato Worm," also known in the South as the tobacco-leaf miner {Gclechia operciilella ^ Zell.), is estimated to destroy 25 per cent, of the potato crop ■ American Naliiralist, 1899, pp. 927-29. New Mexico Bui. 33, pp. 47-51. 2 Cal. Bui. 135, pp. 5-29. 126 THK POTATO on the Pacific Coast. Great losses often occur in stor- age as well as in the field. The moths fly at night, and lay eggs on the stalks and tubers. Destrudlion of the moths by trap lanterns, the destrudlion of infested stems, careful hilling of potatoes, getting them under cover as soon as dug, cleaning up the refuse of the field, and a rotation of crops is recommended. In storage, fumigation with i}4. pounds of carbon bisulphide per thousand cubic feet of air-space will destroy all the larvae if repeated five times at intervals of two weeks. This gas is inflammable, and no lights must be taken near. It is a heavy gas, and sinks from the top of the building. Potato Stalk Weevil, ' ( Trichobaris trinotata). — This beetle attacks the stalks, causing them to wilt. It is found from Canada to Texas and Florida. The vines should be destroyed as soon as attacked, and weeds belonging to the potato family kept down. Another insedl has caused similar trouble in Maine. ^ Grasshoppers {^Mdanophis sp.) do much damage during some seasons, especially after the hay crop is cut, by severing parts of the leaves. Bordeaux mix- ture containing an arsenical poison is the best deter- rent, being better than the arsenical compound alone. The June Bug {Lac/inostcrna sp.). — The big white larvae of these beetles often eat the tubers. They are most prevalent on land which has been in grass, although if land is in clover but one or two years less trouble may be expedled. ' Consult U. S. D. A. Div. of Entomology, Bui. 33, 6. Ind. Report, 1895. Kan. Bui. 82. Pa. D. A. Report, 1896. N. J. Bui. 109, pp. 25-32. '^ Me. Report, 1897, p. 173. OBSTRUCTIONS TO DEVELOPMENT 1 27 Wireworms injure potatoes by boring through them. They are more prevalent on land which has been in grass a few years. Frequent rotation and fall plowing are advised for both of these pests. Other insects injurious to potatoes include: Striped Blister Beetle, or " Old-fashioned Potato Bug" {Epi- cauta vittata). This insecl should be combatted in the same way as the Colorado potato beetle — by applica- tions of arsenical poibons to the foliage. The Tomato Worm and Cutworms are injurious. The latter are very destrudlive at times, and the best remedy seems to be to place bait, made of moist bran and sugar, poisoned with Paris green in the fields.' Arsenical Poisoning-. — Paris green, London pur- ple, and other arsenical compounds usually carry their arsenic in an insolulile form, but some may be soluble. This soluble arsenious oxide may burn the leaves, espe- cially the tips where the mixture flows, and the edges of mutilated leaves, causing death of the spot and a " target-like "' appearance of the leaf. Remedy. — Do not use more than i pound of Paris green per acre, dissolved in 100 to 200 gallons of Bor- deaux mixture. The trouble is most prevalent where people half spray and use Paris green alone, or i pound of Paris green in one barrel (50 gallons) of water and lime or Bordeaux mixture. ' N. J. Bui. 109; Report, 1S95, p. 366. CHAPTER XI SPRAYS AND SPRAYING Fungicides are materials used to combat fungi, or small plants which are usually parasitic. Bordeaux mixture is the leading fungicide for pota- toes. The ingredients for making this mixture are freshly slaked lime and copper sulphate. The fungi- cidal value lies in the copper compound. The lime is added to prevent the copper sulphate burning the foli- age, and to make the mixture more adhesive and more readily seen when applied. The amount of lime and copper sulphate used vary considerabl)-. Not less than 2 pounds of lime can be used to 3 pounds of copper sulphate. Excess of lime is disadvantageous in some ways, as it renders the mixture less efficient by making it thicker, and in this way more liable to settle' and more difficult to apply, causing nozzles to clog, but in a wet season an excess of lime is desirable. A thin mixture can, however, be more uniformly applied. Use freshly burnt, clean, firm lime; slake it by pour- ing water, preferably hot, over it in small amounts at a time, until the lime has fallen to a fine powder ; then add enough water to make a thin paste. A large quantity of lime may be slaked at one time and kept covered with water. This is a " stock solution." To di.ssolve copper sulphate, it should be placed in a (N. Y.) Ceiifva H\il. 243, p. 320. I2S SPRAYS AND SPRAYING 1 29 coarse sack and suspended in the lop of the water in a wood, brass, or porcelain vessel — usuall}^ a wooden barrel, as it corrodes iron. The copper sulphate sinks in the water as it dissolves, and a gallon of water will dissolve 3 pounds of copper sulphate. This is a satu- rated solution. If 6 pounds of copper sulphate are re- quired to a barrel of water, 2 gallons of this stock solution .should be used. Mixing. — It is economical to have an elevated stage, under or alongside of which the spray-cart may be drawn. Place four 50-gallon barrels on this stage, two of which are for the stock solutions of lime and copper sulphate, and two for making the mixture. To make 50 gallons of Bordeaux mixture, pour 2 gal- lons of copper sulphate saturated solution into one barrel and fill it up to the 25-gallon mark with water. Stir up the stock solution of lime and dip out as much as is required; if 5 pounds, then the solution equivalent to this amount; strain it, to exclude particles which might clog nozzles, into the lime-mixing barrel, and fill up to the 25-gallon mark and stir. The mixing- barrels should be provided with 2-inch or 3-inch rubber hose, one end of which is attached in an opening near the bottom of the barrel, the other free. When ready, put the hose from each barrel into the spray-tank, and let them empty and mix together. The rubber hose should be long enough so that the free end can be turned over into its barrel when not in use. If desired, the stock-solution barrels may be placed above and over the mixing-barrels, so that dipping out solution is avoided; it may be run out through a faucet. Convenience to a water-supply expedites the work. 130 THE POTATO Testing Bordeaux Mixture. — In pra<5tice little attention is paid to the quantity of lime, except that suflScient is added to combine with all of the copper sulphate. To determine when this has taken place the potassium ferrocyanide test is made. Purchase ten cents' worth of potassium ferrocyanide, or yellow prussiate of potash, and dissolve it in water. Isabel it ' ' Poison. ' ' Stir the Bordeaux mixture in the spray- tank and take out a sample in a small vessel, to which add a drop of potassium ferrocyanide. If no change in color is noted where it dropped there is sufl&cient lime, but it is better to add lime solution equivalent to a pound of lime more. If the drop changed the color of the solution reddish brown it shows that there is not enough lime. Strength of Solution. — For potatoes, i pound of copper sulphate to 7 or 8 gallons of water is com- monly used; that is : Copper sulphate (blue vitriol), 6 pounds. Quicklime (not slaked), 4 to 6 pounds. Water, 48 to 50 gallons. Bordeaux Dust,' or Dry Bordeaux Mixture, can be made in two ways : 1 , Slaking the lime by pouring a strong solution of copper sulphate over it. 2. Mixing the strong copper sulphate solution with freshly slaked lime which has been made into a paste, then placing the mixture in a bag and drying and pul- verizing it. The two ingredients must be well mixed and passed through a fine sieve. Dry Bordeaux is offered for sale under various names. Adler's Bor- 1 hor details, see Missouri Bui. 60. (N. Y.) Geneva Bui. 243, p. 325. SPRAYS AND SPRAYING 131 deaux is reported to be as efficient as newly mixed,' but generally these preparations are much inferior to the newly prepared, and, when applied drv, are less effective than in the wet form. Washing Soda and Copper Sulphate Mixture. — This mixture is being* used with success in parts of Europe. It does not clog nozzles, spreads evenly over the leaf, and is easily and cheaply prepared. The washing soda is dissolved in water, poured into the barrel of water and stirred, and the copper sulphate added and stirred. Various strengths are in use, but the most satisfadlory one for American conditions has yet to be determined. We are trying 4 pounds of cop- per sulphate, 6 pounds of washing soda, and 50 gallons of water, adding i pound of lime if Paris green is used. A little over i pound of washing soda might be suffi- cient to neutralize the 4 pounds of copper sulphate, but it is safer to use more. In Ireland 5 pounds are used and for three successive 3'ears in extended trials this mixture has given better results than Bordeaux mix- ture." At (N. Y.) Geneva Station, in 1904, it was not so good as ordinary Bordeaux mixture. Spraying with Bordeaux Mixture. — Beiiejits. — Spraying with Bordeaux mixture influences the potato crop in the following ways : 1 . The structure '" of the leaf shows a slight increase in thickness and in strength, and so offers more resistance to the growth of disease spores. 2. The chlorophyll," or green coloring matter of the leaf and stem, is increased. ' Me. Bui. 73, p. 55. - Department of Agrie. for Ireland I ^ FIG. 45 — POTATO SHOVEL fedlly level and firm, so that a potato shovel (Fig. 45) may be used on it when moving the potatoes. Throw the soil from the trench onto each side, making a bank about 15 inches wide with it. This will give a trough about 7 inches deep in which to empty the potatoes. Pile the potatoes neatly, so that the face of the pile at the center will be 3 feet or so high. When sufficient potatoes are stored, place about 3 inches thick of rye or wheat straw (oat straw l^eiiig liable to heat and become mouldy) with the butts down and heads up on the sides and one end of the pile, leaving the other end for additional potatoes (Fig. 46) . Then cover the straw 147 148 THE POTATO with soil, beginning at the bottom and piHng it toward the apex; 2 or 3 inches thick will be sufficient near the top with the straw, and 6 or 7 inches at the base. Finish the surface off by patting it with the spade so ^4 .^ t '*•'■< S^ i.-^v.w- •«^^l ^^^^■1 1 ^r Ji K^ Wifl ^^^^1 ^^ H 4(«-*' ^E. S. R., III., p.493- 152 THE POTATO greatest direcflh' after digging, and in February the losses were higher than the month before or after. The size of the tuber, or whether the variety was early or late, had no perceptible influence. The three early varieties lost from 4.87 to 8.48 per cent., the five medi- um-early varieties from 4.55 to 6.78 per cent., and the four late varieties 5.71 to 7.28 per cent. These losses are believed to be lower than those usually assumed and observed. The loss of weight of these tubers from May to Odtober was 21.57 P^i" cent., considerably more than their loss from Odlober to May i . As soon as the sprouts begin to grow the loss is rapid. Nobbe found that about 75 per cent, of the loss of potatoes in storage is due to loss of water and 25 per cent, to respiration. As the potato is alive and breathes, its existence depends upon its using some of its stored-up energ}-. A ferment changes some of its starch into sugar, and this sugar is used to furnish energy. At low temperatures sugar formation contin- ues, but respiration and the use of the sugar diminishes, and at 30° F. to 28° F. (2° to 4° below freezing-point) respiration almost ceases; hence, frozen potatoes ta.ste sweet because of the accumulation of sugar. E. Wollny believes that between 32° and 50° F. is the best range of temperature for holding potatoes. The acflual losses which may occur in storage as the result of disease cannot be definitely stated. CHAPTER XIV PRODUCTION, TRANSPORTATION, AND MARKETS In the North the potato is a quasi-staple produ<5t. It can be kept a uuniber of months in storage. In the South, except in cold storage, it cannot be kept long and is purely a garden-truck crop, but its culture is extending. 2,836, 196 farmers grew potatoes in 1899. The area was 2,938,952 acres, and the yield 273,328,207 bushels, valued at $98.387. 614- The average value of the produa per acre was $33-48, that of all crops was $10.04, while that of all vegetables was $42.09 per acre. The price per bushel varied between 22 cents in Iowa and Nebraska to $1.10 iu Arizona, the average price being 36 cents. The average yield ' per acre in the year 1879 was 96.7 bushels; in 1889, 83.6 bushels, and in 1899, 93 bushels per acre, although yields of 300 and 400 bushels are common, and over 800 bushels have been obtained. In 1900 six vStates grew 51 per cent, of the potatoes (Figs. 47, 48)— viz.. New York, Wisconsin, Michi- gan, Pennsylvania, Iowa, and Minnesota— while Ohio, Illinois, Maine, Kansas, Nebraska, Missouri, Indiana, and California grew 25 per cent. more. The sandy pine belt region, skirting the lakes, has shown a phe- nomenal increase in potato produ^ion. In Maine, 1 Consult Twelfth Census Report 1902. 153 QlO O 00, S§§2s::^s>-§ w j:- 156 THE POTATO Michigau, Wiscousin, and Minnesota the jjotato acre- age has increased faster than the population in the past ten years. New York comes in the same belt. The per capita producftion of potatoes in the United States is given as about 3.5 bushels.' About one-third of the total crop of the Southern States is shipped North as early potatoes, and some late potatoes are shipped back from the North. The consumption north of Mason and Dixon's line is about 4^ bushels per head, exclusive of potatoes used for seed or starch-making. The South consumes a relatively small amount, being less than i^ bushels per capita. Knowing the approximate consumption and the area and condition of the crop (obtained from the United States Department of Agriculture reports, which are posted monthly), the farmer can form an idea of the outlook of the business. Thus, in 1903 there were 2,916,855 acres grown, and the yield as now known was 247, 1 27,880 bushels. The table below will show the uses to which this crop was put. In 1904 as large an area would need to be planted (a larger one ought to be, because the population is in- creasing); hence, 10 bushels of seed are allowed per acre on : Bushels 2,925 000 acres 29,250,000 Plus 10 per cent, loss in storage . . . 2,925,000 Used for starch-making, etc. (largely small potatoes, etc.) 5,000,000 Available for human consumption . . . 209,952,880 247,127,880 ' Consult Twelfth Census Report, 1902. PRODUCTION, TRANSPORTATION, MARKETS 1 57 The public can consume about three bushels of pota- toes per head per j'ear, and as there were 79,000,000 people to be fed, it would require 237,000,000 bushels to furnish this quantit}-. The shortage of 27,000,000 bushels insured a fair price, 61.4 cents per bushel being the average farm value. The States having a surplus of potatoes are the Southern and Eastern Coast States (notably Maine, Rhode Island, New Jersey, Virginia, and Florida), their market being the cities of the East and interior. The Trans- Mississippi and Nort western States also have a surplus. The potato trade is a home trade. The yield is sel- dom more than is required for home consumption, and several times it has been less — as in 1902, when over 8,000,000 bushels were imported. Factors Influencing Farm Prices. — Farm prices are the net value of farm produces to the producer upon delivery at the local market. Between the grower and the consumer profits must be made by the local buyer, the wholesaler, the retailer, and perhaps a broker or two, and the transportation companies. To yield a profit to the grower the price received from the con- sumer must exceed (i) the expenses of distribution, including transportation, (2) the cost of production. It may not. The market price is regulated by the law of supply and demand. In marketing live stock, cotton, grain, tobacco, and wool the main tendency is to eliminate the expensive middle man. This is easier accomplished with non- perishable produdts than with perishable ones. There are three reasons why the expensive middle man has 158 THE POTATO been retained in the marketing of perishable prod- udls — 1. The extraordinary risks of depreciation. 2. InsuflEicient capitalization of the distribution end. 3. Absence of large-scale handling of the produdts. There is little consolidation in marketing potatoes. Generally speaking, selling on commission is antiqua- ted and should be abandoned, as it is the most demoral- izing feature of farming. The market is more stable when goods are bought and sold outright. An inter- esting feature is that rural districts are doing more of their own banking, so far as the financiering of the grain and some other crops is concerned, and the same will eventually be extended to potatoes. Cold storage improves prices, preventing slumps and excessively high prices, both of which are injurious. High prices inevitably lead to reduced consumption. The absence of public markets where consumer and producer can meet is a noteworthy feature of American cities and towns. Such markets have a salutary effect upon the distributor and middleman wherever they exist. The useless retailers are eliminated and the service of the survivor is improved, and both producer and public are benefited. One important cause of this lack of system is the poor roads. Hauling is high. It costs, on an average, 25 cents to haul a ton of produce a mile, and in manj- cases more. 90 per cent, of all the freight handled by the railroads is brought to them on wagons; most of it is farm produce. With team and man at $3.50 per day, the co.st of hauling this freight aggregates about as much as the cost of running the railroads PRODUCTION, TRANSPORTATION, MARKETS 1 59 one year. It is useless to double the produdlion of the farm unless we increase the facilities for market- ing the produce, and to do this it is imperative that we have good highways. In Belgium loads of farm prod- uce are hauled 60 to 70 miles in competition with the railroad. L,et every farmer join the good roads' move- ment; then he will be able to go to market with prod- uce on days when the land is too wet to work or when the price is high. How many miles will $1.25 haul a ton of potatoes or other farm produce on a road, a trolley road, a railroad, and on water? $1.25 will haul a ton 5 miles on a common earth road ; 12^ to 15 miles on a well-made macadam road; 25 miles on a trolley road ; 250 miles on a steam rail- way; 1,000 miles on a steamship. The value of cheap steamship transportation is seen in the Eastern potato trade. The prices of potatoes are better sustained in the Central States than in the East- ern because, although the tariff of 25 cents per bushel is an ample safeguard for the producer, as soon as potatoes are 50 cents per bushel, wholesale imports from Europe and the West Indies are apt to prevent them from going much higher. The South Atlantic States, from Florida to Virginia, supply the earl}- potato trade of the Eastern cities. The water transportation enables them to handle large quantities at low rates, and to compete with Northern potatoes (old) during at least three months of the year. Modes of Selling. — i. TJic Local Market. — This deserves attention, as higher prices are received in it by the producer than w)ieu shipped away. l6o THE PC)TATO 2. The Distant Market. — Many growers must ship. P^or such, combination is essential. The method adopted by the Eastern Shore potato farmers (Vir- ginia) is noteworthy. There are 2,500 shippers in the Exchange. They sell all their produce through select- ed receivers, appointed by the diredtors, in Xew York, Boston, and Philadelphia. The receivers charge 8 per cent, commission, of which 3 per cent, is given to the agent who solicits the business. This agent should be familiar with the market requirement ■ and give in- struclions in regard to methods of grading, assorting, and packing, and in this way render the produce more valuable. Combinations such as the following com- mend themselves : the use of the " registered label," which is similar to a " union label," and is placed on all packages, or a trade-mark similar to that used by the Farmers' Produce Association, of Delaware, which carries the number of the shipper, and enables the seledled salesman to inform the grower at once if any- thing is wrong. FARMERS' PRODUCE ASSOCIATION OF DELAWARE (27) The contents of this package are GUARANTEED to be as good all through as on top Commission Rates. — In Cleveland potatoes are sometimes sold on a conunission basis of 4 and 5 cents per bushel, or 10 per cent, of the sale price. In St. PRODUCTION, TRANSPORTATION, MARKETS l6l Louis the wholesaler purchases and makes his profit by selling to large customers and hucksters at an ad- vance of ID cents per bushel over what they cost him in car lots. In Cincinnati the rate of commission is 3 cents per bushel. In Kansas City the brokerage for handling is 2 to 2>^ cents per bushel. In Richmond, Virginia, and Atlanta, Georgia, if not sold by the grower, 10 per cent, is the commission. In Lincoln, Nebraska, when potatoes retail at 80 cents per bushel, the money is divided about as follows: Retailer's share, 20 cents; wholesaler's share, 10 cents; railroad freight, 18 cents; seller's commission, 7 cents; net price to producer, 25 cents ; 69 per cent, of the cost to the consumer goes to pay the transporters and distributors, and 31 per cent, to the grower. At Portland, Oregon, the com- mission is 5 per cent. , and the burlap sacks in which the potatoes are handled cost about 5 cents each. The retailers sell at an advance of 10 to 30 cents per sack (100 pounds). AfNew York and Philadelphia 8 and 10 per cent, commission will find good sales- men. The producer usually receives, net, between 25 and 65 per cent, of the retail price of potatoes. Taking a number of market returns, they show that the producer's returns are about 63 per cent, of the price paid in the markets, and of this, in some cases, about half is paid to the railways for transportation if the goods are sent by rail, so that, then, roughly speaking, the producer, transporter, and distributor divide the customer's money equally. The value of a local market, where the producer can sell direct to the consumer, is apparent. l62 THE POTATO Grading. — The proper grading of potatoes is essen- tial to success. Scabby, second-growth, ill-shapen, diseased, and undersized tubers must be removed from first-class grade. The grading may be done by having a sand screen on trestles set at such an angle that the potatoes roll down iito baskets at the bottom, while the dirt falls through, and the seconds and refuse are thrown into baskets or boxes on the side. I^et two men sort and one shovel, and have one emptying and bagging if they go into bags. A sack-holder is a con- venience in filling the bag. The small potatoes and dirt may be removed by a potato-sorter (Fig. 49), of which there are several types on the market. Packages. — Potatoes are sold by the pound, peck, bushel, barrel, cental, and car lot. The early potatoes are shipped in barrels holding 3 bushels ( 1 80 pounds) . A canvas cover is nailed on the head. Such barrels cost about 20 cents, including the cover. The late crop is sometimes shipped in bulk in car lots. In the East seed potatoes are shipped in double-headed bar- rels containing 165 pounds, net. Such barrels cost, new, about 30 to 33 cents. Flour-barrels are often purchased at about 1 5 cents each instead. The high price of new barrels leads some to ship seed potatoes in strong burlap sacks which hold the same amount as a barrel. The sacks cost 15 to 20 cents less than the barrel. Boxes are used for shipping small quan- tities. On the Pacific Coast burlap sacks holding a cental (100 pounds), and costing 5 cents each, are used. Barrels. — Before filling, drive the hoops firm on the bottom and nail with shingle nails; drive on the bulge 1 64 THE POTATO hoops, and secure with 3 or 4 barrel nails; then pro- ceed to fill. The potatoes should be shaken down oc- casionally while filling, and the barrels filled full, and, if headed, the head should be put in where it belongs with a screw press, so that the potatoes cannot rattle. The head should be nailed firmly with shingle nails. If in bags, sack them up well, and tie tight ; or sew up, according to requirements. Bushel Boxes. — For marketing early potatoes in the local market bushel boxes or crates are often used. T. B. Terry uses a bushel box 13x16 inches and 13 inches deep, all inside measurement. The sides and bottoms are of S/s-inch, and the ends are ^-inch, white wood. Hand-holes are cut in each end, and the upper corners are bound with galvanized hoop iron to strengthen them. They cost $25.00 to $30.00 per hundred at the factory, and weigh 6 to 7 pounds each. Each box has a lid, so that in change- able weather the potatoes can be picked up and cov- ered as fast as dug. This box holds five pecks. The legal bushel for grain is 2,150.4 cubic inches, and in measuring potatoes the rule is to heap the half-bushel measure sufficiently to add one level peck to the two level half-bushels. Five level pecks are held in 2,688 cubic inches. These boxes hold 2,700 cubic inches when level full ; hence, they may be piled three or four high on a wagon. The recent introducftion of a crate in which the sides fold onto the bottom when not in use reduces the amount of storage room re- quired by about two-thirds. These crates cost the same as others, and appear to be equally strong. Advantages of a bushel box : PRODUCTION, TRANSPORTATION, MARKETS 165 1 . Potatoes are put in the boxes and covered as soon as dug, thus preventing them from heating in the sun. 2. They are easily and quickly loaded on a wagon, saving time. 3. They are convenient packages in which to carry early potatoes to the home market. 4. The potatoes may be left at the store in the box and delivered in the box when sold, saving handling and bruising. 5. When drawing the main crop to the storage-cellar they are convenient to handle. 6. They may be used for storing seed potatoes, apples, etc. , and carrying seed potatoes to the field to be planted. CHAPTER XV CHEMICAL COMPOSITION AND FEEDING VALUE Composition. — Early attempts were made to deter- mine the food value of the potato by means of chemical analyses. In 1795 Pearson reported "Experiments and observations on the constituent parts of the potato root." Einhof published analyses of the potato in 1805, as did Vanquelin in 18 17. Rather more than fifty years ago Emmons in this country reported anal- yses. Eawes and Gilbert devoted considerable time to the study of the composition of potatoes, and more re- cently various agricultural experiment stations, nota- bly the Conne(5licut State and the Minnesota Agricul- tural Experiment Stations, the Division of Chemistry, U. S. D. A., and various European institutions have been investigating the problem. The approximate chemical composition of a number of varieties is : Water, 75 per cent.; protein, 2.50 per cent. ; ether ex- tracft, .08 per cent.; starch, 19.87 percent.; fibre, .33 per cent.; other non-nitrogenous materials, .77 per cent.; ash, I per cent. A more extended analysis is taken from the Vermont Experiment Station, report 1901: TABLE XII . N) ^1 5 <>5 Dextrin attd Soluble Starch as; Per Per Per Per Per Per Per Per Per Per cent. cent. cent. cent. cent. cent. cent. cent. cetii. cent. 79.41 20.59 14.51 1-35 0.09 0.36 2.28 0.06 1.26 0.68 166 CHEMICAI. COMPOSITION AND MARKET VALUE 1 67 The percentage of water usually ranges between 70 and 80 per cent., the extremes being 65 and 85 per cent. Potatoes contain more dry matter tlian any root crop. Per cent. White turnips 7 to 9 Rutabagas 9 to 14 Mangel-wurzels 9 to 16 Sugar-beets 12 to 24 Carrots 10 to 17 Parsnips 10 to 18 Potatoes 20 to 30 About 85 per cent, of the matter is present in the solid portion, or marc, and 15 per cent, in the juice. It has been believed b}- many that the specific gravity of the tubers varied with the percentage of dry matter, and on this basis tables for ascertaining the dry matter present in the tubers from the specific gravity have been worked out and used considerably. From these data the starch content was determined. Woods,' of Maine, and Watson," of Virginia, found that the ratio existing between the specific gravity and the starch content is not fixed. Starch is the most important constituent of the dry matter of potatoes; it generall}' constitutes 15 to 20 per cent, of the fresh tubers, but may be as low as 10 or as high as 25 per cent. Maine-grown potatoes are usually lower in their starch content than European- grown potatoes. The starch content varies with the variety and the locality. Northern-grown samples of the same variety usually contain more starch than Southern-grown samples." 1 Me. Bui. 57, p. 150. 2 va. Bui. 55, p. 102; Bui. 56, p. 144. ' Va. Bui. 56, p. 144. i68 THK POTATO TABLE XIII DIGESTIBILITY OF POTATOES Potatoes, with eggs, milk, and cream Potatoes, raw i Potatoes, cooked Potatoes dried - and ground. ■i HI III ill Man Pigs Pigs Sheep V S I. ^ P r r p C (3 Per Per Per Per Per cent. cent. cent. cent. cent. 90.6 71.9 93 0 97-0 84-5 82.0 98.1 95-0 82. o 80.0 97.6 So. I 81.5 ^9-5 92.0 44.6 40.0 The above data show that potatoes are almost wholly digestible. Feeding Value, — When abundant and low in price, potatoes may be fed to all classes of stock. In France, Girard fed 55 to 66 pounds of cooked potatoes per day to fattening steers and 4^2 to 6^ pounds to sheep. Von Funke^ found uncooked potatoes were good for all stock except pigs. He fed 60 pounds of raw potatoes, 6 pounds of linseed meal, and 9 pounds of clover hay, with salt, per i ,000 pounds, live weight, per day to fat- tening steers. For milch cows, 25 pounds daily per 1 ,000 pounds, live weight, is the limit. For yearlings, ewes, and wether sheep, 25 pounds per 1,000 pounds, live weight, per day is advised, and fattening sheep, 40 pounds. For horses, about 12 pounds per 1,000 pounds, live weight, may be given with other food. Stock should not be watered soon after feeding pota- toes, but preferably about half an hour before feeding. Potatoes^ are not a valuable food for young animals. 1 Snyder, Minn. Bui. 42, pp. 89, 90. »E.S. R., v., p.8l2. 2 Kellner, et al. E. S. R., XIV., p. 595. * Miuu. Bui. 42, p. 95. CHEMICAL COMPOSITION AND FEEDING VALUE 1 69 as they are deficient iu protein and ash — hence, should not be fed to growing cattle under two years old, lambs, or young pigs, unless in very small amounts, with other food to balance the ration. At Wisconsin Experiment Station,' hogs ate cooked potatoes better than uncooked, and 445 pounds of cooked potatoes were equal to 100 pounds of corn-meal in feeding value. One pound of dry matter of corn is superior to one pound of dry matter of potatoes for making gains with pigs. Cooking. — In cooking potatoes a considerable portion of the albumen may be lost. Peeled potatoes started in cold water lost 80 per cent, of albumen, while those started in hot water lost but 10 per cent. Less is lost if the potatoes are not peeled . Salt should be added to potatoes, because the mineral matter they con- tain is deficient in sodium salts, which are requisite for the human system, and because salt increases the pala- tability. Varieties vary in the time they require to cook, and even soil and cHmatic conditions have an influence. In a floury, mealy potato the starch grains have swollen and burst, and ruptured the cell-walls surrounding them, while in a soggy potato this has not taken place. Potatoes showing second growth will not cook uniformly; the last-grown portion will cook first. When second growth takes place the starch passes from the older portion to the new; hence, when cooked, the older portion appears to be hard and dark, w^hile the newer portion is white and floury, the difference being due to the presence or absence of starch. » wis. Seventh Annual Report, 1S90, and Henry, " Feeds and Feeding," p. 212. lyo THE POTATO Uses. — Potatoes are used as hunian food, stock food, for the manufacflure of starch,' syrup, alcohol, dextrin, etc. Potatoes may be preser\"ed as ensilage" for stock feeding, while the pomace'' resulting from starch manu- fadlure and potato feed ■* have received attention for the same purpose. Potatoes may be dessicated, and in this form can be easily presented in the tropics and ardlic regions, and thus furnish an excellent article of diet in a convenient form for transportation. The in- dustr}^ is small at present, but can be readily extended. > U. S. D. A. Div. of Cheraistrj-, Bui. 5S, * U. S D. A. Farmers' Bui. 79, p. 21. 3 Me. Sta. Report, 1S96, p. aS. Bui. 65, p. 115. * Vt. Bui. S2, p. 72. CHAPTER XVI BREEDING AND SELECTION— PROPAGATION AND BREEDING Potatoes are propagated from seed, cuttings, lay- ers of green shoots, sprouts from the ej'es of tubers, or portions of the tubers containing a bud or eye. About the beginning of the eighteenth century Shirreff, of England, wrote that " the potato is to be considered a short-lived plant, ' ' and that ' ' the only way to obtain vigorous plants and to insure produdtive crops is to have frequent recourse to new varieties raised from seed." Dr. Hunter and T. A. Knight held the same views. T. A. Knight stated that late planting tended to re- invigorate a degenerating variety.' The value of rais- ing new varieties from seed is recognized to-daj^ and for their produdlion some modern breeders selecft as parents two varieties, which in most qualities bear close resemblance to each other, avoiding the use of oppo- .sites, the claim being that it is easier to fix the type. Others, including Burbank and Garton, make crosses between widely divergent types, although it takes longer to fix the ones they seledl and there is a lower percentage worth}- of a trial. There is, however, more chance of obtaining something above the average. Wide crosses adl upon the charadlers in the plant in a manner similar to a vigorous push on the pendulum of a clock — it goes higher on each side: plants of higher 1 Miller's " Gardeners' Dictionary," ed. 1S07, " Potatoes," and Don's " Gardeners' Dictionary," 1831-38, Vol. IV., pp. 4CX3-406. 172 The potato value and plants of lower value than either parent are secured. A plant of high value is secured and grown for a period of 5'ears in order to fix it. Those who have regarded the valuable chara(5lers which led to the selection of the individual as fixtures from the beginning claim that this period of fixing is .solely for the pur- pose of elimination of the undesirable characSters, and that it ought to be termed ' ' the elimination period ' ' rather than ' ' the fixing period. ' ' The interrelationship of different qualities is not well known, but it has been noted that a variety having a few thick stalks yields large tubers, but few in number, while a number of weak stalks is often found with a number of small tubers. Early ripening and resistance to blight or rot {P/iytopht/iora infestans) are not generallj^ found to- gether. It is claimed that a large producftion of seed- balls goes hand in hand with a small produdlion of tubers. T. A. Knight claimed that varieties which did not bloom readily could be induced to do so by removal of the soil from round the tuber-bearing stems, the ex- planation offered being that the plant's failure in tuber produdlion would stimulate the produ(5lion of seed.' In pollenizing varieties artificially the stamens should be removed from the female parent with fine pin- cers just as the bloom opens, or before, and the flower enclosed in a paper or gauze bag. The proper time to apply the pollen is known by the moist appearance of the stigma. The pollen from the desired variety should be dusted on the stigma on two or three successive days. The bag may be removed when the stigma dies < Philosophical Transactions, 1806. BREEDING AND SELECTION 173 and the bloom withers. The fruit, or seed-ball, may contain from 100 to 300 seeds. These are washed from the ripe seed-balls, dried, and at the proper season sown under glass, or in a hot-bed, or out-of-doors in FIG. 50 — POTATO FLOWER, WITH CALYX AND COROLLA REMOVED On the left are shown the anthers closed round the pistil. On the right the anthers are expanded, pistil not shown. The inner surfaces of the anthers show the line where rupture occurs when the pollen is liberated. Gener- ally this occurs only near the upper portion of the anther. flats. The seeds germinate rapidly. Later they are transplanted to a well-prepared piece of land outside. The distance apart varies with different growers — from 12x12 to 26x26 inches, and sometimes more. The up- right stem bears leaves and the axils of the first leaves bear shoots, which turn downward into the ground and bear tubers. The old idea that the first year's 174 THE POTATO crop consist of small tubers, the next larger, and so on, does not always hold, as a tuber weighing over seven ounces has been produced the first year. The Burbank potato was full size the first year it was grown from seed, and many breeders feel that unless the tubers are of edible size the first year they are not likely to be worth fur- ther care. Frequently the tubers do not reach full size until the second year.' The tubers from each plant must be kept separate, the best seledled and planted again. The distance apart varies be- tween 26x 12 and 40 x 40 inches. Wider plant- FIG. 51 — PISTIL OF POTATO FLOWER, SHOWING THE PARTS a— Stigma, where pollen is applied. b — Style, down which the pollen tube goes to the ovary, r, where it fertilizes the ovule, which become the seeds (see ing permits the study of Fig. 3). rf— Attachment of stamens, ,1 ... .J . ^, removed to prevent self-fertilization. tne inaiviaual. ine ^_petals, partly torn away to expose third, fourth, and fifth ovary, /—sectional view of calyx. year field culture is given, and a variety may be found worthy of a name and further trial before distribution. The breeder's aim is to produce varieties which excel in produdlivity, power to resist diseases, earliness, quality, percentage > Minn. Bui. 87, p. 10, BREEDING AND SELECTION 1 75 of starch, and have other desirable characteristics — as, suitable shape, color, depth of eyes, etc. Selection. — Hybridizing is of small value unless attended by careful seledlion and vigorous elimination of the poorer types. All potatoes tend to vary in cul- tivation, either to improve or degenerate. This varia- tion is more marked in some plants than in others; hence, once a varietj'^ is established, the j-ield may be materially increased and the rapid deterioration of the variety prevented b}- selecftion of the best plants. Seledlion must be made in the field, not from the bin. The whole plant must be considered, not a single tuber. Goff' showed that by perpetuating the most productive and least produdlive plants of Snowflake potatoes the total jdeld of the most produdlive one for two years was 322 ounces, while that of the least pro- dudlive was but 100 ounces, and, summarizing fourteen years' trials, the most producftive plants yielded 180 per cent, more than the least producftive. Bolley, at North Dakota, found that "equal weight pieces from small or large tubers of the same vine are of equal value, provided all are uormall)- mature," * confir- matory evidence that the whole plant is the unit of seledlion. Growers may at least maintain the produdlivity of their stocks of potatoes by careful seledlion of the best plants when digging, careful storage of these tubers, and then using all of them for seed. These might be planted by themselves on a piece of good land, and se- ' (N. Y.) Geneva Report, 1SS7, p. 85. Wis. Report, 1S99, p. 306. » N. D. Bui. 30, p. 243. 176 THIt POTATO ledlions made from them at the following harvest, the oest plants being again retained for the nursery plat and the balance used as seed. A. Girard,' one of the foremost potato growers of France, seledls his potatoes every year from those hills whose foliage is especially lujcuriant. He uses the variety Richter's Imperator, and prepares the soil to a depth of 12 to 16 inches, giving a liberal applica- tion of barn-yard manure and fertilizers, acid phos- phate, sulphate of potash, and nitrate of soda. He selecfts, for planting, tubers weighing from 3}^ to 4 ounces. When he cannot get such, he recommends that tubers of 7 ounces in weight be cut in two, and tubers of 10^ ounces into three pieces — always cutting in the diredlion of the greatest length. He insists on the reje(5lion of all potatoes weighing more than 11 ounces. If the potatoes available for planting weigh less than 3^ ounces he places in each hill several smaller tubers, enough to bring the total weight to about 4 ounces. He lays great stress on the distance between the plants; the rows are 24 inches apart and the tubers are planted 1 9 inches in the rows, these dis- tances having been determined to be best by careful experiment. He advises early planting, as soon as danger from frost is past. The crop should be well worked and all potatoes kept covered, and the tops well sprayed with Bordeaux mixture, and the crop not dug until all of the tops have withered. Farmers in the co-operative experiments under his dire(5lion report yields of 400 to 700 bushels per acre as common, and ' E. S. R., v., p. 117. BREEDING A^;D SELECTION 177 even up to 1,353 bushels per acre with a starch content of 20 to 25 per cent. One farmer secured almost 10,000 pounds of .starch per acie, probably one of the largest jdelds of carbohydrates ever obtained from an acre of land. APPENDIX Spray Calendar Disease or Insect Spray Mixture First Spraying Second Spraying Third Spraying Fourth Spraying REMARKS Early Blight Bor- deaux mixture When plants are 4 to 6 in. tall 7 to 14 days later 7 to 14 days later 7 to 14 days later Late Blight Bor- deaux mixture As for early blight do. do. do. Up to 7 spray- ings are some- times given Rosette Treat the seed Flea- beetle Bor- deaux mixture When beetles appear Repeat if neces- sary As for I and 2 A deterrent only Colorado Polato- beutle or "Bugs" and Blister- beetles or old- fashion- ed Potato bug Paris green or other arsenites in Bor- deaux mixture When beetles appear Repeat if neces- sary As for I and 2 I pound Paris green per acre in 100 gallons or more of Bor- deaux mixture. Arsenate of lead, 3 pounds to 50 gallons. Arsenite of lead, 3 pounds to 50 gallons. Green arsen- 0 i d I pound per 100 gallons. Grass- hopper Paris green or other arsenites in Bor- deaux mixture When they appear Repeat if neces- sary As for C 0 1 o- rado beetle 179 l80 THE POTATO Seed Treatment Disease Treatment Scab Soak uncut seed in formalin, I pound to 30 gallons of water, for two hours; then dry and plant on scab-free soil. Rosette {Rkizoctonia) . As for scab. Dry Rot Diseased tubers to be destroyed; those in contact with them to be treated as for scab and sprayed as for blight. Wet Rot (due to Blight or Bacteria) .... Have seed potatoes in such storage that they can be examined, and these tubers sorted out and de- stroyed. Do not plant affected tubers. Soaking them in forma- lin, as for scab, is advisable in some cases, depending on the cause. Stem Rot or Dry End Rot {Fusariurii oxysi>o- rum) It attacks the stem-end first; hence, cutting off this end of suspected tubers will reveal the diseass^ Discard diseased tubers. INDEX PAGE Acid Phosphate 43,47,119 Acme Harrow 23 Ammonium Salts as Fertilizers 31 32, 42, 47, 119 Area in Potatoes in 1899 . . 153, 15(i in 1903 156 Arizona Potato 1 Arsenate of Lead 135, 137 Arsenical Poisoning .... 123, 137 Arsenious Oxide 136 Arsenite of Lead .... 135, 137, 138 Lime 135, 138 Soda 135 Available Phosphoric Acid . . 43 Bacteria, Useful 40, 41 Bacterial Diseases 122 Bag;s 161, 162 Barium Arsenite 138 Barn Manure ... 36, 37, 44, 46, 119 Amounts used 36, 37 Barrels 162, 164 Filling 163 Size of 162 Bermuda Potato 4. 5 Black Death 135 BUght, Early, or Leaf Spot Dis- ease 118, 178 Late, or Rot . 112, 113-117, 121, 17B Blister Beetles 127, 178 Blooms 4. 5 Encouraging 172 Blossoming 16, 172 Bordeaux Dust, or Dry Bor- deaux 130 Bordeaux Mixture . 115, 116, 118, 123 124, 128, 131 Benefits from Use of . 115, 118, 124 131, 132 for Flea-beetles 123, 124 Mixing 129 Strength of Solution 130 Testing 130 Botany 1-7 Boxes 162 Bushel 164, 165 Breeding 171 Buckwheat 29 as a Cover Crop 29 in a Rotation 29 Bug Death 135 PAGt Bugs, or Potato Beetle . . . 134, 125 Bundle Blackening, or Dry End Rot 122, 179 Bushel, Weight of a 162 Calcium, Influence of . . . . 35, 36 Calco Green 138 Carbon Bisulphide 126 Castor Pomace 32 Cellars, Construction of ... . 149 for Storing 149,150 Temperature of 150, 152 Ventilation of 150 Chloride, Calcium, injurious . . 34 Chlorides, Injurious toGro^-th, 34,43 Varieties with Heavy Foliage Readily Injured by 34 Climate, Influence of . .8, 66, 111 Clover, Value for Plowing Un- der 27, 28 Red 27 Crimson 27, 28 Sweet 28 Clover, Influence on Yield ... 27 Cold Storage 153, 158 Color of Skin 76 Colorado Beetle 124, 125 Commission Rates 160, 161 Composition, Chemical 132, 166, 167 Inlluenced by Spraying. . . . 132 Consumptiou of Potatoes . 156, 157 Cooking 169. 170 Quality 70, 72-74 Co-operative Methods of Mar- keting 160 Copper Arsenite 138 Sulphate 138, 129 Cottonseed-meal 32, 48 Cost of Selling 161 Cover Crops 28, 29 Cow-peas, Value for Plowing Under 27, 38 Crepidodera cnciimeria, or Flea- beetle 133 Crop Producing Power of Soil Reduced IS Cultivation 105-109 Method of 107 Tools Used In 107 Cultivations, Number of . .105, 106 l8l l82 INDEX PAGE Culture, Level 107 Systems of 106 Cutworms 127 Darwin's Potato 1 Date of Planting 96 Depth of Planting ...... 93-96 Influence on Quality 90 Influence on Tuber Forma- tion 94, 95 Dessicated Potatoes 170 Digestibility of Potatoes .... 168 Diggers, Mechanical .... 144-146 Digging the Crop 117, 143 Methods 143, 144 Disease Resistance Required in a Variety 71 Relation of Temperature to . 9 Disease-resisting Varieties . 75, 116 Disk Harrow 23, 24 Disparene 135, 137 Distance Apart 91-93 Doryphora decemlineata, or Po- tato Beetle 124, 1S5 juncta, or Southern Potato Beetle 124 Drainage 17, 116 Dried Blood 31 Drills 106 Dry End Rot 122 Dry Rot 122 Early Blight 118, 179 Planting 97 Ensilage, Potato !70 Epicauta vitatta 127 Epitrix siibcrinata, or Flea- beetle 124 Eyes 6 Depth and Frequency of . .71, 79 Relation of Number of Stallcs Produced to 62, 63 Farm Prices 157, 161 Feed, Potato 170 Feeding Potatoes to Stock . 168, 169 Value 168, 169 Fertilizers 30, 31, 37-40 Amounts Used 30, 37, 38 Applying 48 Compoiuiding 46 Cost of 45 For Early Potatoes .... 35, 39 Function of 39^1 Important Ingredients in . 42, 43 Influence of I'eriod of Growth Upon the Necessary .... 31 Mixing 46, 47 Poor Mixtures of 47, 48 Profit from Use of 37, 38 PAOB Fertilizers, Purchasing . 42, 43, 44,45 Value of Home Mixing of . . 46 Valuable .... 37, 38, 40, 176, 177 Valuing 39,40,43-46 Fixing New Varieties 172 Flavor 60, 74 Flea-beetle 82, 114, 118, 123 Punctures Injurious . . 82, 114, 118 Flowers 3, 5 Formalin 69,118,119,122 Too Strong a Solution Injuri- ous 69 Fungicides 128 Fusarium oxysporum . . . 122, 179 Gelechia Operculella Zell., Po- tato Worm 125, 126 Good Roads, Value of . . . 158, 159 Grading Potatoes 162 Grasshoppers 126 Green Arsenite 135 Green Arsenoid 135, 138 Growth, Conditions Influenc- ing 8, 16, 30 Effect of Chlorides on ... . 34 Influence of Dry Weather on . 9 Manuring 30 Influence of Respiration on . 9 Influence of Time of, on Fer- tilizing 31 Obstructions to Ill, 127 Period of 14, 31 Habitat of Potato 1 Hammond's Slug Shot 135 Harrow, Acme 23 Disk 24 Spike-tooth 107 Spring-tooth 23, 24 Harrows, Action of, on the Soil 24 Harvesting 143 Methods of 143 Hauling Farm Produce . . 158, 159 Cost of 158, 159 Haulm 34,71,80,81 Hellebore 135 Hilling 14, 16 Time of 16 Hills 106 Hunuis, A Food for Bacteria . . 41 Effects on Physical Proper- ties of the Soil 23 In Soils 21, 41, 42 Influence of Tillage on . . . . 105 Influence on Depth of Plowing 21 Influence on Soil Moisture . . 23 Hybridizing 171-173 Imports of Potatoes 157 INDEX 183 PAGE Insecticides 135,136 Insuluble Phosphate of Lime . 43 Introduction into Virginia ... 2 into Europe 3, 7 Irrigation, Amount of Water Used in 48, 49 Dangers of 49 Value of ......... 48,49 June Bug 126 Kainit 43,48,119 Kno-bug 13.5 Lachnostema 126 Late Planting 97 Laurel Green 13.5,138 Leaf 71,81,82,114,131,132 of Rust-resistant Varieties of Wheat 82 Spot Disease, or Early Blight 118, 178 Value of a Tough, Hard . . 81, 82 Level Culture 106,107 Objections to 100 Light, Influence on Yield ... 8 Lime 35, 36, 41, 119, 128 Uses 41, 128 Liming 31,32 London Purple 135 Loss of Potatoes in Storage 151, 152 Ma.crosporiu»i solani. or Early Blight 118. 178 Manure 30, 36, 37, 44 Amounts Applied 36, 37 Influence of .30 Value 44-46 Manuring, Reasons for 30 Marketing, Cost of 160, 161 Markets 157, 158 Distant 157, 160 Local 159, 161 Maturity, Time of 71,79,80 Melanoplus sp 126 Mexican Potato 1 Moisture, Conservatiou of Soil, 22, 23 Influence of 8, 9 Mulch, Soil 106, 109 Mulching 110 Nitrate of Soda . . . 31, 82, 42, 47, 48 Effect on Buds 69 Nitrates 42 Nitrogen 30, 31, 42 Effect of Excess 31 Influence of 31 Occurrence in Fertilizers . . 42 PAOK Nitrogen of Barn Manure ... .36 Requirement while Young . . 31 Sources of 31, 48 Nozzles 141,142 Organic Nitrogen of Fertilizers 42 Oospora scabies (Thax.), Scab, n9, 131 Packages 161 Paragrene 135, 138 Paris Green . . 124, 123, 127, 135, 136 Amount to use 125, 127 for Flea-beetles 124 for Potato Beetles 125 Peas in Rotation a? Phosphatic Fertilizers . 35, 42, 43, 47 Effect on Maturity 35 Phosphoric Acid, Influence of . 35 Phytophthora infestans. Blight or Rot 113-117, 121 Pits 147-149 Pimply Potatoes 134 Pink Arsenoid 135, 137 Planters 100-104 Hand 100, 101 Horse 101-104 Planting, Date of 96, 97 Depth of 14,93-96 Distance Apart 91-93 Early and Late 97 Hand 59. 97-100 Influence of Depth on Depth at which Tubers Form . . 94-96 Influence of Depth of, on Quality 96 Methods of 59, 97-100 Plow, Potato or Shovel 144 Plowing 21-23 Conditions Governing ... 21, 22 Deep 21,42 Depth of 21,23 Fall 21 Plowing, Spring 22 Pollen 3, 173 Pollenizing 173 Pomace, Potato 170 Potash, Amounts Applied . . 33, 38 Influence of 31 , 33 on Leaves 32 on Quality 33, :M on Roots .32, 33 on Starch Formation . . 33, :J4 on Tubers 33, 33 Muriate of ... . 33, 34, .38, 43, 119 Amounts Used 38 Sources of 33 Sulphate of .... 33, 84, 43, 119 Potassic Fertilizers 43 Potassium Ferro-Cyauide . . . 130 Potato Beetle I34, 60 Trichoharis trinotata 126 Tuber Formation . 6, 16, 54. 55, 94 95. 172 Depth of 54, ,55, 94, 95 Retarding of 172 Stimulation of 54, .55 Tubers, Hollow 74 Number Formed by a Plant . 74 Rate of Growth of 16 Size of Seedling 173. 174 Type, Varieties Not True to . 72, 85 Unit Value of Fertilizers . ... 44 Uses of Potatoes iTo Value per Acre 153 Varieties . . 19, 51, 72, 7.",, 76,83-90 171-174 Breeding New 171-174 Disease-resisting 76 PAGE Varieties, Duplication and Re- naming of 85.86 Fixing New 172 Importance of New 171 Improvement in 84 Influence of Soil and Condi- tions on 19, 87 Influence of, on Yield .... 75 Life of aiodern 83 Life of Older 83, 84 List of 88-90 Most Popular 87-90 Staying Power of 83 Testing 86 True to Name 85 True to Type 72 Variety, Selecting a 70-90 Variation in the 52-54 Viability of Tubers 66-09 Vigor of the Plant . . 71, 82-85, 118 Indications of Deficiency in . 84,85 Washing Soda and Copper Sul- phate 3Iixt\ire 131 Water. Available 48 Requirement 33. 48-50 Effect of Fertilizers on . . . 33 Per Pound of Dry Matter . 50 Weeder 108 Weeds, Injurious 105 Wet Rot 121, 122 AVhale Oil Soap 136 ■\Mieat, Depth at which Roots Form 15 Varieties Resistant to Rust . 83 White Arsenoid 138 Wild Potato 1 Wireworms 127 Wood Ashes 43, 119 Yield . . 7, 14, 26-28, 70, 74, 75, 84, 87 132, 134, 153 Average 74, 1.53 Effects of Sprouting Upon . . 58 Influence of a Crop of Clover on 27,28 Influence of Light Upon ... 8 Influence of Soil on . . . 19, 20, 87 Influence of Spraying on . 132, 134 Influence of the Variety Upon 19, 20, 75, 87 Maximum 74 STANDARD BOOKS PUBLISHED BY ORANGE JUDD COMPANY NEW YORK CHICAGO Ashland Building People's Gas Building 315-321 Fourth Avenue 150 Michigan Avenue Any of these books rvill be sent by maiU postpaid, to any part of the world, on receipt of catalog price. We are always happy to correspond with our patrons, and cordially invite them to address us on any matter pertaining to rural books. Send for our large illustrated catalog, free on appli- cation. First Principles of Soil Fertility By Alfred Vivian. There is no subject of more vital importance to the farmer than that of the best method of maintaining the fertility of the soil. The very evident decrease in the fertility of those soils which have been under cultivation for a number of years, combined v^ith the increased competition and the advanced price of labor, have convinced the intelligent farmer that the agriculture of the future must be based upon more rational practices than those which have been followed in the past. We have felt for some time that there was a place for a brief, and at the same time comprehensive, treatise on this important subject of Soil Fertility. Professor Vivian's experience as a teacher in the short winter courses has admirably fitted him to present this matter in a popular style. In this little book he has given the gist of the subject in plain language, practically devoid of technical and scientific terms. It is pre-eminently a '"First Book," and will be found especially valuable to those who desire an introduction to the subject, and who intend to do subse- quent reading. Illustrated. 5x7 inches. 265 pages. Cloth. Net, $i.ou The Study of Corn 3y Prof. V. M. Shoesmith. A mjst helpful book to all farmers and students interested in the selection and im- provement of corn. It is profusely illustrated from photo- graphs, all of which carry their own story an>,' contribute their part in making pictures and text matter a clear, con- cise and interesting study of corn. Illustrated. 5x7 inches. 100 pages. Cloth Net, $0.50 (1) The Cereals in America By Thomas F. Hunt, M.S., D.Agri. Professor of Agron- omy, Cornell University. If you raise live acres of any kind of grain you cannot afford to be without this book. It is in every way the best book on the subject that has ever been written. It treats of the cultivation and improvement of every grain crop raised in America in a thoroughly practical ana accurate manner. The subject-matter includes a comprehen- sive and succinct treatise of wheat, maize, oats, barley, rye, rice, sorghum (kafir corn) and buckwheat, as related particu- larly to American conditions. First-hand knowledge has been the policy of the author in his work, and every crop treated is presented in the light of individual study of the plant. If you have this book you have the latest and best that has been written upon the subject. Illustrated. 450 pages. 5^x8 inches. Cloth $1.75 The Forage and Fiber Crops in America By Thomas F. Hunt. This book is exactly what its title indicates. It is indispensable to the farmer, student and teacher who wishes all the latest and most important informa- tion on the subject of forage and fiber crops. Like its famous companion, "The Cereals in America," by the same author, it treats of the cultivation and improvement of every one of the forage and fiber crops. With this book in hand, you have the latest and most up-to-date information available. Illus- trated. 428 pages. 5^x8 inches. Cloth $I75 The Book of Alfalfa History, Cultivation and Merits. Its Uses as a Forage and Fertilizer. The appearance of the Hon. F. D. Coburn's little book on Alfalfa a few years ago has been a profit revela- tion to thousands of farmers throughout the country, and the increasing demand for still more information on the subject has induced the author to prepare the present volume, which is by far the most authoritative, complete and valuable work on this forage crop published anywhere. It is printed on fine paper and illustrated with many full-page photographs that were taken with the especial view of their relation to the text. 336 pages. 6V2 X 9 inches. Bound in cloth, with gold stamp- ing. It is unquestionably the handsomest agricultural refer- ence book that has ever been issued. Price, postpaid, . $2.00 Clean Milk By S. D. Belcher, M.D. In this book the author sets forth practical methods for the exclusion of bacteria from milk, and how to prevent contamination of milk from the stable to the consumer. Illustrated. 5x7 inches. 146 pages. Cloth $100 (5) Bean Culture By Glenx C. Sevev, h.S. A practical treatise on the pro- duction and marketing of beans. It includes the manner of growth, soils and fertilizers adapted, best varieties, seed selec- tion and breeding, planting, harvesting, insects and fungous pests, composition and feeding value ; with a special chapter on markets by Albert W. Fulton. A practical book for the grower and student alike. Illustrated. 144 pages. 5x7 inches. Cloth $0.50 Celery Culture By W. R. Be.^ttie. A practical guide for beginners and a standard reference of great interest to persons already en- gaged in celery growing. It contains many illustrations giving a clear conception of the practical side of celery culture. The work is complete in every detail, from sowing a few seeds in a window-box in the house for early plants, to the handling and marketing of celery in carload lots. Fully illustrated. 150 pages. 5x7 inches. Cloth $0.50 Tomato Culture By Will W. Tracy. The author has rounded up in this book the most complete account of tomato culture in all its phases that has ever been gotten together. It is no second- hand work of reference, but a complete story of the practical experiences of the best-posted expert on tomatoes in the world. No gardener or farmer can afford to be without the book. Whether grown for home use or commercial purposes, the reader has here suggestions and information nowhere else available. Illustrated. 150 pages. 5 x 7 inches. Cloth. $0.50 The Potato By S.\MUEL Fr.vser. This book is destined to rank as a standard work upon Potato Culture. While the practical side has been emphasized, the scientific part has not been neglected, and the information given is of value, both to the grower and to the student. Taken all in all. it is the most complete, reliable and authoritative book on the potato ever ptiblished in Amer- ica. Illustrated. 200 pages. 5x7 inches. Cloth. . . $0.75 Dwarf Fruit Trees By F. A. Waugh. This interesting book describes in detail the several varieties of dwarf fruit trees, their propagation, planting, pruning, care and general management. Where there is a limited amount of ground to be devoted to orchard purposes, and where quick results are desired, this book will meet with a warm welcome. Illustrated. 112 pages. 5 x 7 inches. Cloth $0.50 (6) Cabbage, Cauliflower and Allied Vegetables By C. L. Allen. A practical treatise on the various types and varieties of cabbage, cauliflower, broccoli, Brussels sprouts, kale, collards and kohl-rabi. An explanation is given of the requirements, conditions, cultivation aiid general man- agement pertaining to the entire cabbage group. After this each class is treated separately and in detail. The chapter on seed raising is probably the most authoritative treatise on this subject ever published. Insects and fungi attacking this class of vegetables are given due attention. Illustrated. 126 pages. 5x7 inches. Cloth $0.50 Asparagus By F. M. Hexamer. This is the first book published m America which is exclusively devoted to the raising of aspara- gus for home use as well as for market. It is a practical and reliable treatise on the saving of the seed, raising of the plants, selection and preparation of the soil, planting, cultiva- tion, manuring, cutting, bunching, packing, marketing, canning and drying, insect enemies, fungous diseases and every re- quirement to successful asparagus culture, special emphasis be- ing given to the importance of asparagus as a farm and money crop. Illustrated. 174 pages. 5x7 inches. Cloth. . $0.50 The New Onion Culture By T. Greiner. Rewritten, greatly enlarged and brought up to date. A new method of growing onions of largest size and yield, on less land, than can be raised By the old plan. Thousands of farmers and gardeners and many experiment stations have given it practical trials which have proved a success. A complete guide in growing onions with the great- est profit, explaining the whys and wherefores. Illustrated. 5x7 inches. 140 pages. Cloth $0.50 The New Rhubarb Culture A complete guide to dark forcing and field culture. Part I — By J. E. Morse, the well-known Michigan trucker and originator of the now famous and extremely profitable new methods of dark forcing and field culture. Part II — Com- ])ilcd by C I). I'lSKE. Other methods jiracticcd by the most experienced market gardeners, greenhouse men and experi- menters in all parts of .America. Illustrated. 130 pages. 5x7 inches. Cloth $0.50 (7) Alfalfa By F. D. CoBUnx. Its growth, uses, and feeding value. The fact that alfalfa thrives in almost any soil; that without reseeding, it goes on yielding two, three, four, and sometimes five cuttings annually for five. ten. or perhaps lOO years; and that either green or cured it is one of the most nutritious •'orage plants known, makes reliable information upon its pro- luction and uses of unusual interest. Such information is given in this volume for every part of America, by the highest authority. Illustrated. 164 pages. 5x7 inches. Cloth. $0.50 Ginseng, Its Cultivation, Harvesting, Marketing and Market Value By Maurice G. Kains, with a short account of its history and botany. It discusses in a practical way how to begin with either seed? or roots, soil, climate and location, prep.aration planting and maintenance of the beds, artificial propagation, manures, enemies, selection for market and for improvement, preparation for sale, and the profits that may be expected. This booklet is concisely written, well and profusely illus- trated, and should be in the hands of all who expect to grow this drug to supply the export trade, and to add a new and profitable industry to their farms and gardens, without inter- fering with the regular work. Xew edition. Revised and en- larged. Illustrated. 5 x 7 inches. Cloth $0.50 Landscape Gardening By F. A. Waugh, professor of horticulture, university of Vermont. A treatise on the general principles governing outdoor art; with sundry suggestions for their application in the commoner problems of gardening. Every paragraph fs short, terse and to the point, giving perfect clearness to the discussions at all points. In spite of the natural difficulty iif presenting abstract principles the whole matter is made entirely plain even to the inexperienced reader. Illustrated. 152 pages. 3x7 inches. Cloth Net, $0.75 Hedges, Windbreaks, Shelters and Live Fences By E. P. PowKLL. A treatise on the planting, growth and management of hedge plants for country and suburban homes. It gives accurate directions concerning hedges ; how to plant and how to treat them: and especiafly concerning windbreaks and shelters. It includes the whole art of making a delightful home, giving directions for nooks and balconies, for bird culture and for human comfort. Illustrated, i-io pages. 5x7 inches. Cloth $o.."0 (8) Farmer*s Cyclopedia of Agriculture A Compendium of Agricultural Science and Prac- tice on Farm, Orchard and Garden Crops, and the' Feeding and Diseases of Farm Animals ^y EARLEY VERNON WILCOX, Ph. De o«? CLARENCE BEAMAN SMITH. M. S Associate Editors in the Office of Experiment Stations, United States Department of Agriculture THIS is a new, practical, and complete presentation of the whole subject of ag- riculture in its broadest sense. It is de- signed for the use of agriculturists who desire up-to-date, reliable information on all matters pertaining to crops and stock, but more particularly for the actual farmer. The volume contains Detailed directions for the culture of every important field, orchard, and garden crop grown in America, together with descriptions of their chief insect pests and fungous diseases, and remedies for their control. It contains an ac- count of modern methods in feeding and handling all farm s*:ock, including poultry. The diseases which affect different farm animals and poultry are described, and the most recent remedies sug- gested for controlling them. Every bit of this vast mass of new and useful information is authoritative, practical and easily found, and no effort has been spared to include all desirable details. There are between 6,000 and 7,000 topics covered in these references, and it contains 700 royal 8vo pages and nearly 500 superb half-tone and other original illustrations, making the most perfect Cycloiiodia of .Agricul- ture ever attempted. Handjotnely bound in cloih, ^3.50; half morocco (■Very jumpluouj). ■^4-. 5 O, postpaid nOAilf^F llinn OnLIDAUV 315-321 Fourth Avenue, New Yorli.N Y. UKANUlL JUUU LUMrAH I, Peoples Gas Building, Chicago. IK. (19) University of British Columbia Library DUE DATE .,- ^ T FORM 310 nWX «l - 4. evil 00(r^^^ r^ 2 AGRICULTURE LIBRARY