BULLETIN _ OF THE Agricultural C3" Mechanical College of Texas (in cooperation with the United States Department of Agriculture) AUGUST, 1916 EXTENSION SERVICE No. B. 27 Growing and Storing Sweet Potatoes Address CLARENCE QUSLEY Director and State Agent, College Station, Texas Growing and Storing Sweet Potatoes By A. T. Potts, Associate Professor of Horticulture Agricultural and Mechanical College and J. C. Olsen, Agricultural Engineer, Extension Service Agricultural and Mechanical College of Texas. SELECTION OF SOIL. Most tuberous plants develop best in a loose, pliable soil that will readily permit the formation of a smooth, uniform product. For this reason a sandy loam soil is considered best for sweet potatoes. Such land, if properly fertilized, will give more satisfactory crops than heavier soils. Each year the demand is greater for early sweet potatoes. Earli- ness is aided by selecting soil sloping to the south, so as to receive the maximum warmth in the early spring. Good drainage is essential. Not only is a wet soil cold and late, but sweet potatoes grown there are more subject to disease. A southern slope of the land need not be considered in planting the main crop. The depth of the soil should be such as ‘to permit the free develop- ment of the roots and to furnish an ample reservoir for food and moisture. SOIL PREPARATION. The soil should be plowed eight or ten inches deep in the fall. In some cases it may be advisable to harrow and bed the land at once to aid in drainage. In general, the land may be allowed to lie until spring, when it should be disced and thrown into beds about four feet apart. The beds should be harrowed until well pulverized. FERTILIZERS. If fertilizer is used it should be applied ten days or two weeks before the slips are set. This is commonly done by opening a furrow in the bed, applying the fertilizer and mixing it with the soil with a small plow. The furrow is then closed until planting time. Mr. E. P. Sluckey, Horticulturist of the Georgia Experiment Station, recommends 1040 pounds of the following mixture per acre: Acid Phosphate 16 per cent . . . . . . . .1000 lbs. Nitrate of Soda 15 per cent . . . . . . . 250 lbs. Cotton Seed Meal (2 1-2—7—-1 1-2) 675 lbs. Sulphate of Potash 50 per cent . . . . . .300 lbs. Dean E. J. Kyle of the Texas Agricultural and Mechanical College says a better plan for Texas soils would be to apply a good coating of manure in the fall and in the spring apply 400 or 500 lbs. per acre of the following mixture: Acid Phosphate . . . . . . . . . . . . . . . . .1200 lbs. Cotton Seed Meal . . . . . . . . . . . . . . . . o 800 lbs. The free use of hardwood ashes will reduce the amount of potash required. If a heavy application of unleached wood ashes is made, it is bet- ter to apply it to the crop that preceeds sweet potatoes than to the potato crop direct, for potatoes grown on very fertile soil are frequently cracked and misformed. The grower should make a careful study of his soil and plant behavior upon it before making any applications of commerical ferti- lizer. The use of stable manure and cowpeas is nearly always advisable, even on the best potato soils. The manure used should not contain any decayed potatoes, as it is almost certain to cause serious loss by disease in the crop. - VARIETIES. There are several varieties of sweet potatoes grown in every section. This is not satisfactory when cooperative storage and marketing is to be followed. The varieties often vary much in time of maturity, disease re- sistance, time to cure and keeping qualities. The potato jobber knows all of these points and also that his customers demand uniform potatoes in any single lot. Cars of mixed potatoes seldom bring satisfactory prices. Each community should try to confine their planting to one, or, at the most, two varieties. If more than one variety is grown they must be harvested, stored and marketed separately. The varieties to grow depend on the market to be supplied. The Northern and Eastern markets demand a dry, mealy potato, such as the Big-Stem Jersey, including the so-called Carolina, Gold Coin and others. The markets of the South demand a moist, sweet tuber. Among the varieties most in demand in the South are the Nancy Hall, Dooley Yam, Pumpkin Yam and Triumph. GROWING THE PLANTS. There is good reason to believe that a more careful field selection of seed potatoes would give more satisfactory crops. It has been a com- mon custom to select the seed from the bank or storage house at bedding time without regard to the behavior of the parent plant. This certainly will not improve the strain and is very likely responsible for the “running out” of varieties. The grower should select his seed at harvest time and cure and store separately from the main crop. Great care should be taken at bedding time to see that the tubers are sound, smooth and of reasonable size. “Shoestrings” and tubers showing discolored areas should not be used. The grower should have firmly fixed in his mind the characteristics 3 of his variety and choose only those plants approaching nearest to this. Not only must he watch the size, shape, number of tubers, time of ‘ma- turity, freedom from disease and general quality of the tubers, but the character of the plant’s growth and its general ability to resist adverse climatic conditions. Most potato beds are not provided with artificial heat, but, owing to the growing demand for early tubers, this step is likely to receive more attention. There is a liberal demand for potatoes during June, July and August, before the bulk of the crop is ready, and even those of low quality bring high prices. Early maturing varieties should be selected for this crop. In Central Texas the hot beds are prepared about February 15th. The seed beds are located on a well drained place convenient to water. If the bed can be located south of a building, it will gain some protection from cold. It is customary to remove the surface soil to a depth of six or eight inches, six feet wide and as long as is desired. Boards 1x12” are set aroundthe edge of the excavation. Fresh horse manure is placed in the pit and carefully packed. The manure should not contain over 50 per cent of bedding or litter. Eight to twelve inches of manure is con- sidered enough to give sufficient heat to run the bed until danger of frost is past. Glass sash is the best covering for the beds, to keep out water and prevent frost, but many growers are using sheeting or mats woven from sorghum or sudan grass. After the manure is packed evenly into the pit it should be sprinkled, but not wet. Two or three inches of the sur- face soil should be placed on the manure and pulverized. The temperature of the bed may be very high after a day or two, so that it is advisable to de- lay placing the seed potatoes until it has cooled to some extent. The seed potatoes are then placed upon the soil and lightly pressed down. They should not touch each other, as this would aid in the spread of decay. After the potatoes are placed on the bed three or four inches of surface soil is thown over them. Where artificial heat is used great care must be given to watering and ventilaton. The bed will require more Water than if no heat is used. The covering must be removed entirely on warm days and even during cool weather some air must be admitted. For the main crop of slips, artificial heat is not used. The seed may be placed in a bed similar to the above without the manure, or simply bedded in the open without any protection. Many growers start a few plants in hot beds and use the vines from these to set the main crop. There are several factors favoring this method and the vine cuttings make as good, if not more satisfactory, crop. If vine cuttings are used, it is advisable to “heel” them in for a few days in a moist, shady place where they will start roots readily and are thus enabled to grow off more prompt- ly in the field. The slips are ready to transplant to the field when five or six inches high. There is nothing gained in setting the slips until the soil is warm. The sweet potato, like cotton and melons, grows to perfection only where there is an abundance of heat. ._ ha”). ~.._. _..‘..u.. In removing the slips from the bed, it is best to have the soil rather moist to prevent breaking or injuring the roots. It is also advis- able to place one hand on the soil over the seed piece to prevent moving it and injuring the other developing shoots. The plants are set about 20 inches apart in the row. Various de- vices may be used to facilitate this work, but the hands alone are most commonly used. There is a form of short-handled hoe with a V-shaped blade that is gaining in favor. Very rapid work may be done with this device and it prevents some of the backache common to this task. Where vine cuttings are used and planting is being done just after a rain, a forked stick may be used to shove the vines into the soft soil. In any method, it is very essential that the soil be quite firm about the inserted plant. Failure in this regard is one of the chief sources of loss in trans- planting. In all cases the-young plants must be carefully protected from drying sun and wind. CULTIVATION. The field should be cultivated as soon as practicable after setting and at frequent intervals throughout the growing season. Not only is this necessary to conserve moisture and keep down weeds, but also to admit air, which is essential for all root crops. In cultivating, care should be taken not to injure the vines. These have as important a function to perform as the roots and their injury or removal for forage will reduce the yield of the crop. DISEASES. The chief requirment in growing a successful crop of sweet pota- toes is that the seed potatoes shall be sound. The moist, sweet, starchy root is a good place for the development of decay. Not only will decay prevent the production of the maximum number of slips (or draws) but those produced may be infected with the disease and so transmit it to the potatoes formed in the field and infest the surrounding soil. The spores of many decay-producing fungi live for several years in the field, so that future loss may be great from an infected field, even if sound seed are used. Many tubers will be lost in the field before harvest, but the chief injury will be found in the storage houses where the decay spreads as the potatoes sweat; early sales or constant sorting to prevent further losses are then forced upon the grower. ' Do not plant any seed pieces which show discolored patches, as these are the surface indications of one of several rots, which have re- mained more or less dormant during the winter, if the roots have been stored in a dry bin, but are likely to become serious when placed in moist soil. The danger is not that the seed pieces will rot, but that in their rotting they will infect the soil with fungus which may then be transferred to the field where slips are planted. The use of seed potatoes from bins in which any considerable amount of rotting has occurred is very unwise, as all the potatoes in such a bin are more or less dusted with the spores of rot-producing fungi and will carry the disease to the sprouting bed, un- 5 HmDOm UZHMDO OQQAHQQ QHEwDM 3w < hO wzir» .\/\Q\k.¢\\w|W|~l..N 20\.k.~v\\-.NJ.U NQ\W ‘llnlu- I‘IIIJ _.ll|l. 1 | l A E ‘l: W a I %~L\\O.OK hkukbnxflkQ \~.\n\~m| m ;._..___._- ._..- -_-- HmDOE UZQHDO OHQm wvzbtfilm. zObrkUh-wm mnQqwA '. a: 0o g 4/459 .>\¢.4Q $004K; w. . -\O* Q\ >\ tux . X .4 . mmmom ..$\<:>2\N\L\ Qzu. ..0>I>2\&|\ uQ\m: UZHMDU oa x8 0/ : Z, ’/“%'I/6"bO/-f ‘f ; mas/m a“ ' '../‘ Camera/d’ 0r bP/Ck- \ . ' DETAILS 0F‘ WALLS, Poor“ & FLOOF?" 9 PLANS OF A 650 BUSHEL POTATO CURING WAREHOUSE. less preventive treatment is given. Soaking the seed potatoes in a for- malin solution (1 pint, or pound, of commercial formalin to 30 gallons of water) for two hours will kill the fungus spores and not appreciably in- jure the potatoes, if they are promptly drained and dried in a clean place after treatment. Seed potatoes may, also, be disinfected by soaking ten minutes in a solution of one ounce of bichloride of mercury to eight gallons of water. - Dry well before using. The seed bed should be soaked with either of the above solutions. This should be done three days before bedding; after twenty-four hours stir well with a manure fork and allow to stand forty-eight hours before bedding seed. Another essential in the production of‘ sound plants is clean soil. Do notluse the same place for bedding potatoes two years in succession, as any disease which may have been introduced the first year will likely be more serious the secod year. It has been found that sweet potatoes may safely follow corn in the field rotation, as these two crops are not subject to the same diseases. In drawing the plants from the seed bed, it is advisable to examine the stem and roots and to discard all those showing dead places or dark areas. By careful attention at this time, much of the rot injury in the field will be prevented. As a further precaution against rot in the field, dip the slips as drawn from the bed, using the formalin, or bichloride of mercury solution, already mentioned. The surplus liquid may be shaken off and the slips handled as usual. The diseses causing decay in sweet potatoes are almost entirely in the soil and develop in the roots. No treatment of the disease is possible. The precautions mentioned above will be of greater value than any soil treatment. INSECTS. Sweet potato insects are not very numerous, but some of them may be quite serious. Cut worms may be serious in the seed bed or field. They are easily controlled by placing poisoned bran mash about the plants (50 pounds wheat bran, 2 pounds powdered arsenate of lead or 1 pound Paris green, 5 pounds of sugar or syrup and enough water to moisten.) r ' The flea beetles are small brown, jumping insects that eat holes in the leaves of potatoes and related plants. They are rather shy and move very rapidly, so may not be readily seen. They are controlled by spraying with arsenate of lead paste, 3 pounds to 50 gallons of water (or powdered 1 1-2 pounds.) The gold bug or tortois beetle is another insect that does considerable damage by eating holes in the leaves of the potato, morning glory, moon flower and related plants. It is about the size of a ladyjbird beetle and if once seen it will be remembered by its beauti- ful golden color. It may be controlled with arsenate of lead spray. It is best to direct the spray on the underside of the leaf. 1O The sweet potato weevil is probably the most destructive insect to sweet potatoes. Fortunately it has not become widely distributed, The adult insect is about one-fourth inch long, with the wing covers, beak and head of blue black, while the body is reddish brown. The larva does the damage by tunneling into the tubers and roots, the eggs being laid in shal- low cavities in the tuber. There is no remedy that will reach the pestywhen it has gained entrance into the potato. The careful selection of seed from weevil-free areas, the complete destruction of all vines, culled pota- toes and rubbish, together with selection of weevil-free soil are the chief methods of control. HARVESTING. Careful handling is necessary for any perishable crop. The sweet potato is one of the most exacting in this respect. Any breaking of the skin renders the tuber subject to a number of rot-producing organisms. These disease germs are always present in the field and in storage. For this reason it is not practicable to store or ship tubers showing injury. Mature sweet potatoes are more resistent to injury than those harvested before reaching this stage. A mature potato has the ability to form a crust or covering over an injury, so that decay may not readily enter. If immature, the surface “bleeds” and the crust forms more slowly, if at all. This moist surface is an ideal place for the collection and develop- ment of disease germs. Maturity, then, is the first consideration in harvesting the crop. The only excuse for digging before maturity is to reach an empty market early in the season, for immediate sale and consumption, or to harvest late crops before frost. There are a number of ways of removing the vines and digging the tubers. One of the best tools to use is a plow made’ for this purpose. It has two rolling coulters attached to the beam to cut the vines on each side of the row. The point is-shaped like a middle-buster, but has the mold-boards extended with rods so that the soil may sift through and leave the potato to drop on the surface. In any system used, the plow should be run deep enough to sift out the tubers without cutting or brusing; The tubers should be picked up by hand and placed in crates or baskets. Sacks should never be used for handling this crop. The potato may be graded in the field or hauled to the curing sheds and separated there. In any case, the crop should be handled as little as possible. Shift- ing the tubers from place to place is a source of injury and especially be- fore curing. Sound tubers are absolutely essential to successful market- ing. One prominent grower said: “My reputation for shipping only sound potatoes is worth more than the value of five crops, and I never take any chances with it.” The crop should be sized and graded before being placed in storage. The Ofiice of Markets and Rural Organizations of the United States Depart- ment of Agriculture has suggested the following grades that are now ac- cepted on nearly all markets and by most growers: 11 First grade—-Prime (or N0. 1 Bakers.) This grade will include all potatoes of one variety from two to three inches in diameter, with none over seven inches in length, all to be fairly uniform in shape, clean, bright, natural color and sound. This grade must be free from bruises, scars, irregular, crooked, rotten, or diseased potatoes. Second grade——Choice (or No. 2 Bakers.)This grade will include all potatoes of one variety from 1 3-4 to 3 inches in diameter, with none over eight inches in length, all to be clean, bright, natural color, sound and free from rot or disease. This grade may include crooked and irregular potatoes. Third grade—Jumbo ( or large size potatoes.) This grade may include all potatoes of one.variety over 3 inches in diameter, with none over eight inches in length, all to be clean, bright, natural color, sound and free from rot or disease. SEED STOCK. The seed stock ordinarily takes all sound potatoes, free from rot or disease, cuts or bruises, and less than 1 3-4 inches in diameter. It is estimated that about 65 per cent of the crop will be Prime and Choice, while the remainder will be Jumbo and seed stock. Most potatoes are wanted for baking, hence the adoption of the above grades. The Jumbo stock is largely used at home or for canning and pies. Pota- toes not falling within the limits of grades as given should not be placed upon the market. SWEET POTATO HOUSE. To keep sweet potatoes in good condition after they are gathered it is necessary that they be thoroughly dried and cured after being put into the house. They should be placed in a storage house where a uniform temperature can be secured by artificial heat. The house should be so constructed as to permit of thorough ventilation when necessary. In cold weather it should be possible to make it nearly air tight. k The Wooden house is probably the best building for storing sweet potatoes. It is cheap and easy to keep dry. Concrete,‘ brick and stone houses, due to the fact that it is difiicult to keep moisture from collecting on the walls, are not as satisfactory. The sweet potato house shown in the drawings on pages 7 to 10 is giving excellent results in Texas. It meets all the essentials required in storing sweet potatoes. The potatoes can be taken out at any time without subjecting them to unfavorable con- ditions. Instead of being rushed on the market at digging time, when the price is low, potatoes can be held and marketed when the price is right. A cheaper house than the one shown in the following drawings will keep the sweet potatoes, but the additional attention and fuel required would soon exceed the extra cost required for the better house. It is economy to build a substantial house at the start. HOUSE CONSTRUCTION. The plans as shown in this bulletin are for a house holding 600 to 700 bushels. By following the general plans of this house a storage house of a smaller or larger capacity can very easily be designed. The Exten- 12 sion Service has drawings of a 2500 to 3000, and a 10,000 to 12,000 bushel house from which blue prints will be made and sent to any one desiring to build houses of that size. The construction of the 600 to 700 bushel house is discussed in the following paragraphs: HOUSE SHOULD BE BUILT ON PILLARS. The sweet potato storage house should be built on piers, in order to allow a free circulation of air under it. Three rows of pillars should be built, using concrete, brick, or wooden blocks. The two outside rows of pillars should be 17 inches above and the center row 15 inches above the ground line. FLOOR CONSTRUCTION. The two outside sills are 6”x6” and the centre sill is 6”x8”. The joists, which are placed 2 feet apart, should be 2”x8” material. Over the joists a rough floor of boards should be laid, then a layer of heavy build- ing paper and over this, shiplap. WALL AND CEILING CONSTRUCTION (PAGE 10.) The walls should be built by placing 2”x4” studding 2 feet apart. On the outside a layer of 1” sheathing is nailed to the studding, then a lay- er of heavy building paper is tacked to the sheathing, and over this drop siding 0r some other matched siding should be used. On the inside of the building heavy building paper should be tacked to the studding and then covered with shiplap, The walls should be tied together every four feet with 2”x4” scantling. These scantlings should come over the partitions for the bins so that they may be used for supports. ROOF CONSTRUCTION (PAGE 10.) For the roof, 2”x4” rafters are placed 2 feet apart. Over the rafters building paper should be tacked, and over this the sheathing is nailed. Three ply prepared roofing, shingles or galvanized iron can be used to cover the sheathing. Under the rafters a layer of building paper should be tacked and over this the shiplap. VENTILATION. Thorough ventilation is very necessary in a storage house. There are four ventilators in this house, one for each corner. The roof venti-- lators should be provided with a roof to keep out the rain, and a shutter, which can be closed in cold weather. Two roof ventilators should be used for this house. BIN CONSTRUCTION. The bins are constructed to permit a free circulation of air around the potatoes. The bins are 4 feet wide, 7 feet 7 inches long, and 4 feet deep. They are built up in two tiers. A removable floor 4 feet above the lower floor divides each bin into two compartments. With this arrangement the weight of only 4 feet of potatoes comes on the lower potatoes. The construction allows for a 2-inch 13 air l space between bins, a 4-inch space under bins, and 6 inches between the bins and outside walls. For the corner and middle supports, 2”x4” scantlings are used, nailing the lower end to the floor, and the up- per end to the cross ties used for tying the sides of the building together. Over the supports 1”x4" boards should be nailed, leaving a 1” space be- tween them. In making the floor, 2”x4” scantlings should be cut to go across the bin and placed on edge, one near each end and one in the center. To these should be tacked 1”x4” boards, leaving 1" space between them. The bin floor should not be fastened to the floor of the house. If left looseit can be taken out when the house is cleaned and disinfected in the summer. Both sides of the scantlings between the bins should be slatted up in order to leave an air space. The removable floor separating each bin into two compartments is also made of 1”x4" strips. BILL OF MATERIAL AND ESTIMATED COST OF SMALL SWEET POTATO HOUSE, (BRYAN, TEXAS, PRICES.) Size of House: 12 x 18 feet. Capacity: 650 bushels. Sills . . . .. 2 Pcs. 6”x6”x18’ No. 1. Y. P. 108 feet . 1 Pcs. 6”x8”x18’ No. 1. Y. P. 72 feet Joist .11 Pcs. 2”x8”x12’ No. 2. Y. P. 176 feet Studding 11 Pcs. 2”x4’*’x18’ No. 2. Y. P. 132 feet . 8 Pcs. 2”x4”x12’ N0. 2. Y. P. 64 feet . . . 2 Pcs. 2”x4”x16’ No. 2. Y. P. 21 feet Rafters . .11 Pcs. 2”x4”x16’ No. 2. Y. P. 117 feet Ties through building . .. 5 Pcs. 2”x4”x12’ No. 2.-Y. P. 40 feet Plate . . . . 2 Pcs. 2”x4”x18’ No. 2. Y. P. h 24 feet 754 feet at $25.00 $18.85 Sheathing: 1100 feet at $25.00 $27.50 a T&G floor. 8 Pcs. 1”x6”x12’ best g 48 feet at $32.50 1.56 Drop siding 700 feet at $32.50 $22.75 Shiplap 1150 feet at'$25.00 $28.75 Lumber for Bins: ' 140 Pcs. 1”x4”x16’ 750 feet 7 Pcs. 2”x4”x18’ 84 feet 10 Pcs. 2”x4”x16’ 107 feet 941 feet at $30.00 $28.23 Finishing Lumber: 4 Pcs. 1”x4”x20' . . .27 feet 3 Pcs. 1”x4” 18’ . . .18 feet 2 Pcs. 1”x4”x16’ . . .11 feet g2 Pcs. 1”x4”x14’ .. .10 feet 66 feet at $40.00 2.64 6 Rolls building paper .75 4.50 14 3 Ply prepared roofing, 3 1-4 squares 2.75 8.94 1 Check rail window 1.50 1.50 Hardware: 35 lbs. 20d nails 25 lbs. 10d nails ‘ 35 lbs. 8d nails 95 lbs. at 5 cts. 4.75 12 Bolts 3-4x18” ' 18 cts. 2.16 3 pair 7” Tee hinges 15 cts. .45 1 Stove ' 10.00 Piers: Concrete 1: 2 1-2: 5 mixture: 7 Sacks cement 65 cts. 4.55 3-4 cubic yard sand 1.25 .93 1 1-2 cubic yard gravel 1.25 1.87 Paint: - 3 Gallons q _ 1.25 3.75 Estimated cost of materials 173-68 10 per cent for contingencies 17-37 Labor estimated 20 per cent of materials 38.21 Total cost of house . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $229.26 CARE OF POTATOES IN STORAGE. After the potatoes are graded, they are placed in the bins with all possible care to avoid bruising, and the grades are kept separate. They are stacked as high as possible in the back of the bins, so as to prevent injury by stepping on them. In large storage houses the space should be divided into sections so that the bins in one may be filled and the heat started at once. A temperature of 95 to 105 degrees F., with plenty of ventilation, should be maintained for 1O days or 3 weeks, depending on weather conditions and the variety of potatoes. Ventilation is absolutely necessary. Leave the ventilators open, so as to drive out the moisture- laden air. The house may be closed at night, and should" be kept closed on cloudy days, but if moisture begins to deposit on the walls or ceiling the house should be opened and a fire started to drive off the moisture. The air inside the house should be kept warmer than the outside air dur- ing the curing period. This will prevent moisture from being deposited on the walls. As the air warms it expands and takes up moisture. When it cools it contracts and gives up its moisture. This makes it important to get the moisture-laden air out of the house by ventilation. When the potatoes are thoroughly dried or cured the temperature should be grad- ually reduced to 55 degrees F. and kept as near that point as possible during the remainder of the storage period. If the temperature goes below 48 degrees a fire should be made and the house opened in the middle of the day whenever the temperature on the outside is high 15 enough. When the temperature goes above 60 degrees F. the house should be opened in the cool of the day to lower the temperature to 54 or 55 degrees and then closed. The house should have some ventilation every day. In mild weather the ventilators in the roof may be partly open all the time, but they should be closed in cloudy or cold weather. A sharp look-out should be kept for diseased tubers and any such should be removed from the building. No potatoes of any kind should be allowed to remain under the bins or in the passage ways, but destroyed by burning or by burying deep in the soil. As quickly as the house isemptied in the spring it should be well cleaned and disinfected by burning sulphur. It should be recleaned and fumigated just before filling in the fall. Fumigation will not prevent de- cay if it has once started. MARKETING. The type of package to be used in marketing should receive care- ful consideration. Sacks should never be used. They permit bruising and never make an attractive package. Crates hampers and barrels are in general use and seem to give satisfaction. In many cases these con- tainers are lined with paper. A paper lining is of especial value if there is any liklihood of the potatoes being subject to cold weather. In preparing a package for market it is very essential that nothing but sound stock be used. The tubers must be free from injury or any appearance of rot. Cut or broken tubers should be rejected. The sizing and grading should be in strict conformity with the rules mentioned above and the grades stamped upon each package. 16