When the house is once thoroughly cured, ship ping can begin at any time, when the price or market demand justifies. As a rule, stored potatoes are not shipped until about Thanksgiving time, when the ordinary unstored stock is either used up or is of such poor quality as to offer no competition. Some growers prefer to hold their entire supply of potatoes until late winter or early spring, but ordi narily shipping begins as soon as cool weather comes on. The bin should never be disturbed until ship ment is to begin. The potatoes in storage will not stand moving. Unfortunately their life is limited after being taken from the storage bin. While a stored sweet-potato may keep until May, if left in the place where cured, when taken out and barreled it will probably rot in about a month. Even at the end of a week a barrel of stored potatoes may be gin to show some rot, and at the end of two or three weeks a good many rotten ones may be found. On the other hand, a single potato may often be taken from the top of the bin, carried into the house and kept for weeks. Even the movement or disturbing of the potatoes in the bin results in their destruction. It is necessary, therefore, when a bin is once opened to keep shipping continuously, say two or three times a week, otherwise the exposed potatoes may begin to decay.
A large part of the sweet-potato crop is shipped in three-bushel barrels, the same size as the apple or flour barrel. Occasionally "snide" or irregular sized barrels are used, but these do not ordinarily pay the shipper. On the other hand, potatoes may be shipped in sugar barrels and large packages of any kind when they are sold by weight. In New Jersey, Delaware and Maryland a one and one-half bushel basket made or fashioned after the Delaware peach basket has come into use. Some of these hold a bushel and some one and one-fourth bushels.
In shipping in winter it is necessary to use con siderable care to avoid having the stock frozen, though it will stand considerable cold if not too long exposed. On the other hand, sweet-potatoes frequently suffer from the heat. The disturbance of sorting and barreling causes them to sweat. If they are shipped in open-head truck barrels under a burlap cover, the cover should be removed on their arrival on the market. In warm weather it is often better to bore several ventilating holes an inch in diameter or with a hatchet to remove a chip from several parts of the barrel.
The Yellow Jersey type of potato is usually pre ferred by northern markets. On the approach of warm weather, however, in March and April, this sweet-potato ordinarily loses quality and becomes slightly out of season. Of late years the trade in the so-called yam or sticky sweet type of potato has increased, especially for the spring and early summer trade. Southern people usually prefer the yam type of sweet-potato at all seasons. Some of the yams keep better, or actually improve in quality in the spring of the year, and these yams may be kept through to June or July, when sweet-potatoes from Florida and the Gulf coast begin to arrive.
The result is that the market is continually sup plied with this vegetable throughout the year. As a rule, growers of the Yellow Jersey close out their stock in March. April is the season for bedding, so that attention is then given to the seed bins.
Enemies.
The crop of sweet-potatoes grown in the field is generally remarkably healthy and free from both fungous diseases and insect enemies. However, there are some pests on the foliage and some very serious diseases on the roots.
Black-rot (Ceratocystis fimbriata).—This disease is more troublesome in the storage house and hotbed than it is on the crop in the field. It is a pronounced fungous disease and usually appears as large, irreg ular black spots, slightly sunken in the skin of the potato. On cutting or breaking them open, these spots are found to be deep, usually extending through the skin and sometimes into the central part of the potato. They are of a peculiar blue black tint, ordinarily distinguishable from ordinary rots or other fungous diseases. Even though sweet potatoes may be apparently free from disease when placed in the storage house in the fall, this rot often develops badly. The infected potatoes are rendered bitter and worthless, and are unsalable when the spots are bad. Black-rot is particularly objectionable in the seed-roots, as when these are bedded the disease is started in the hotbed producing the so-called "black shank" or black-rot of the plants. The failure of black-rot-infected plants is more pronounced during the cool, moist weather than during a hot spell. In fact, on a vigorous variety the disease is largely outgrown during favorable hot weather.
The best remedy for black-rot is the use of slip seed. It is advisable to grow the crop of vine cuttings on new land which is not infested, or on land which has never grown sweet-potatoes or has not been in sweet-potatoes for several years, thus making an absolutely clean start, even though the vine cuttings are taken from an infected crop. Another remedy is to clean and sweep the storage house both overhead and underneath before putting in the potatoes, and whitewash the entire interior of the house with a spray pump. The addition of boiled lime and sulfur to the whitewash would undoubtedly be an improvement. The whitewash would then consist of the ordinary lime-sulfur wash thickened with lime. The hotbed should have all the old soil removed, and the boards and (in the case of a fire hotbed) the floor thoroughly white washed with freshly slaked lime before new earth is put in. The new soil should be from ground that has never been in sweet-potatoes. Early bedding and early planting out in the field are objectionable, as they put the crop at a disadvantage. In the same way, digging late in the fall encourages black-rot, while early digging just before the first frost, when the weather is still warm, seems to be particularly desirable. The black-rot is the worst of the dis eases of the sweet-potatoes.