The oat plant belongs to the grass family. It is a hardy plant and, under good conditions, a vigorous grower. It stands cold and wet better than any other cereal except possibly rye. Oats like a cool, moist climate. In warm climates, oats do best when they are sowed in the fall. In cooler sections, spring seeding is more generally practiced.
Allow potatoes to dry thoroughly before they are stored, but never allow them to remain long in the sunshine. Never dig them in damp weather, for the moisture clinging to them will cause them to rot. After the tubers are dry, store them in barrels or bins in a dry, cool, and dark place. Never allow them to freeze.
Among the common diseases and insect pests that attack the leaves and stems of potato vines are early blight, late blight, brown rot, the flea-beetle, and the potato beetle, or potato bug. Spraying with Bordeaux mixture to which a small portion of Paris green has been added will control both the diseases and the pests. The spraying should begin when the plants are five or six inches high and should not cease until the foliage begins to die.
Scab is a disease of the tubers. It may be prevented (1) by using seed potatoes that are free from scab; (2) by planting land in which there is no scab; and (3) by soaking the seed in formalin (see page 135).
Like other crops, potatoes need a thoroughly prepared seed-bed and intelligent cultivation. Break the land deep. Then go over it with an ordinary harrow until all clods are broken and the soil is fine and well closed. The rows should be at least three feet from one another and the seeds placed from twelve to eighteen inches apart in the row, and covered to a depth of three or four inches. A late crop should be planted deeper than an early one. Before the plants come up it is well to go over the field once or twice with a harrow so as to kill all weeds. Do not fail to save moisture by frequent cultivation. After the plants start to grow, all cultivation should be shallow, for the roots feed near the surface and should not be broken. Cultivate as often as needed to keep down weeds and grass and to keep the ground fine.
Be careful to select seed from sound potatoes which are entirely free from scab. Get the kinds that thrive best in the section in which they are to be planted and which suit best the markets in which they are to be sold. Seed potatoes should be kept in a cool place so that they will not sprout before planting-time. As a rule consumers prefer a smooth, regularly shaped, shallow-eyed white or flesh-colored potato which is mealy when cooked. Therefore, select seed tubers with these qualities. It seems proved that when whole potatoes are used for seed the yield is larger than when sliced potatoes are planted. It is of course too costly to plant whole potatoes, but it is a good practice to cause the plants to thrive by planting large seed pieces.
If the land selected for potatoes is lacking in humus, fine compost or well-rotted manure will greatly increase the yield. However, it should be remembered that green manure makes a good home for the growth of scab germs. Hence it is safest to apply this sort of manure in the fall, or, better still, use a heavy dressing of manure on the crop which the potatoes are to follow. Leguminous crops supply both humus and nitrogen and, at the same time, improve the subsoil. Therefore such crops are excellent to go immediately before potatoes. If land is well supplied with humus, commercial fertilizers are perhaps safer than manure, for when these fertilizers are used the amount of plant food is more easily regulated. Select a fertilizer that is rich in potash. For gardens unleached wood ashes make a valuable fertilizer because they supply potash. Early potatoes need more fertilization than do late ones. While potatoes do best on rich land, they should not be overfed, for a too heavy growth of foliage is likely to cause blight.
No grower will harvest large crops of potatoes unless he chooses soil that suits the plant, selects his seed carefully, cultivates thoroughly, feeds his land sufficiently, and sprays regularly.
The soil should be free from potato scab. This disease remains in land for several years. Hence if land is known to have any form of scab in it, do not plant potatoes in such land. Select for this crop a deep and moderately light, sandy loam which has an open subsoil and which is rich in humus. The soil must be light enough for the potatoes, or tubers, to enlarge easily and dry enough to prevent rot or blight or other diseases. Potato soil should be so close-grained that it will hold moisture during a dry spell and yet so well-drained that the tubers will not be hurt by too much moisture in wet weather.
Maize, or Indian corn, and potatoes are the two greatest gifts in the way of food that America has bestowed on the other nations. Since their adoption in the sixteenth century as a new food from recently discovered America, white potatoes have become one of the world's most important crops.
The storage of sweet potatoes presents difficulties owing to their great tendency to decay under the influence of the ever-present fungi and bacteria. This tendency can be met by preventing bruises and by keeping the bin free from rotting potatoes. The potatoes should be cleaned, and after the moisture has been dried off they should be stored in a dry, warm place.
The sweet-potato vine makes a fair quality of hay and with proper precaution may be used for ensilage. Small, defective, unsalable potatoes are rich in sugar and starch and are therefore good stock food. Since they contain so much water they must be used only as an aid to other diet.
In harvesting, extreme care should be used to avoid cutting and bruising the potato, since bruises are as dangerous to a sweet potato as to an apple, and render decay almost a certainty. Lay aside all bruised potatoes for immediate use.
For shipment the potatoes should be graded and packed with care. An extra outlay of fifty cents a barrel often brings a return of a dollar a barrel in the market. One fact often neglected by Southern growers who raise potatoes for a Northern market is that the Northern markets demand a potato that will cook dry and mealy, and that they will not accept the juicy, sugary potato so popular in the South.
Sweet potatoes will do well after almost any of the usual field crops. This caution, however, should be borne in mind. Potatoes should not follow a sod. This is because sods are often thick with cutworms, one of the serious enemies of the potato.
It is needless to say that the ground must be kept clean by thorough cultivation until the vines take full possession of the field.
The sweet potato draws potash, nitrogen, and phosphoric acid from the soil, but in applying these as fertilizers the grower must study and know his own soil. If he does not he may waste both money and plant food by the addition of elements already present in sufficient quantity in the soil. The only way to come to reliable conclusions as to the needs of the soil is to try two or three different kinds of fertilizers on plats of the same soil, during the same season, and notice the resulting crop of potatoes.
The fact that there are over eighty varieties of potatoes shows the popularity of the plant. Now it is evident that all of these varieties cannot be equally desirable. Hence the wise grower will select his varieties with prudent forethought. He should study his market, his soil, and his seed (see Section XVIII).
Four months of mild weather, months free from frost and cold winds, are necessary for the growing of sweet potatoes. In a mild climate almost any loose, well-drained soil will produce them. A light, sandy loam, however, gives a cleaner potato and one, therefore, that sells better.
