According to the Twelfth Census, the sweet potato is the most extensively grown vegetable in the United States, next to the Irish potato. In 1899 it was reported by 1,001,877 farmers, 0 more than one-third of the number reporting Irish potatoes. The acreage, including that of yams, was 537,447, and the value of the crop in 1899 was $19,876,200. The five leading states in production were North Carolina, Georgia, Virginia, Alabama and South Carolina. They produced 52.1 per cent of the aggregate crop. Georgia, North Carolina, Alabama, South Carolina and Texas cultivated, in the order named, 70,620, 68,730, 50,865, 48,831, 43,561 acres, which constituted 52.6 per cent of the acreage of the crop of 1899. The acreage of the south Atlantic division was 49.1 per cent of the total ; the south central, 39.9 ; the north central, 6.2; the north Atlantic, 4.5, and the western division only 0.3.
Culture.
Climate.—The sweet-potato demands, for best results, a rather warm, moist climate in the growing season. An ideal season is one which has frequent showers from April and May, when the crop is planted, into July or early in August; then when the crop is maturing in August and Septem ber, rather dry weather should follow. This is particularly true of the much-grown Yellow Jersey type of sweet-potato, which is retarded by drought before the plants are established and requires con siderable moisture for proper growth. On the other hand, cold rains on tl.e young plants are objection able. North of the cotton-growing districts heat seems to be the important and frequently lacking requirement. In the cotton-belt, however, the tem perature conditions are more favorable.
Soil. —The sweet-potato likes a warm, sandy soil that is well drained and well aerated. Light sandy soils may sometimes be benefited by artifi cial drainage if the subsoil is slowly pervious. The highest yields are often secured on sandy knolls on which corn would fire or burn, and other crops suffer from lack of water. New, cleared land on which a crop of corn has been grown raises fine crops of sweet-potatoes. Successful crops are often grown on soils that are not ideal, provided they lie on hill slopes and are otherwise exceptionally well drained. The red clay hills in the Piedmont region of the Atlantic and Gulf states grow good crops, although, as a rule, commercial cultivation is not attempted on these soils. Some clays are crumbly and grainy so that they allow the neces sary aeration, and the droughty character of the soil may prove favorable.
Fertilizers.—The sweet-potato is especially sus ceptible to artificial fertilizers and manures, and on droughty soils where weak vine-growth is likely they should be employed. Humus is essential. For
old land, growers sometimes haul pine leaves or "woods trash" to the fields in the winter and plow it under to supply humus. Light straw manure is very favorable. Crimson clover sod is especially valuable for this purpose when old land is to be used. If used as a cover-crop, crimson clover should be plowed under when it has made half its growth. Cowpeas are excellent, but they disinte grate rather too rapidly ; and while the cowpea land works up well in the spring, it does not retain its humus through the season so well as the clover. As a rule, the cowpeas should be left on the ground, or perhaps, pastured by hogs, and plowed under in the spring two or three weeks before planting. Rye plowed under when it is just shooting into head is also excellent, though by no means as good as the clover. [See below, under Preparation of the land.] Place in the rotation.—Sweet-potatoes do very well after corn, cantaloupes, tomatoes and most other field and garden crops, with the exception, perhaps, of root crops. In general, planting after fall-dug root crops is not to be recommended. Corn, melons, tomatoes and certain other crops give an opportunity for sowing crimson clover at their last cultivation, and there is nothing better for the sweet-potato crop than to plow under crim son clover when it is about six or eight inches high. Early dug potatoes and early harvested vegetable crops can be cleared from the land and crimson clover sown. Cowpeas may be sown in the same way, but for the later crops this is not so desirable.
With heavy manuring and fertilizing sweet potatoes can be grown on the same land for several years with good results, but this practice is not to be recommended. The writer has had excellent crops for three years in succession, but generally the second crop has been the best. This is doubt less the result of the accumulation of manure and fertilizer from the previous crop. The third crop begins to feel slightly the injurious effect of con tinuous cropping. One evil of successive crops of sweet-potatoes on the same land is that too little opportunity is afforded for cover-crops and for the addition of humus. Sweet-potato vines decay so completely that they add little humus to the soil. With early dug sweet-potatoes, however, especially toward the South, crimson clover or rye, or even winter oats, can be sown to supply organic matter.