The manufacture of starch and other products from corn is an industry of increasing magnitude. The chief starch derivatives are dextrine and glucose or grape sugar (used in brewing beer and as a substitute for true sugar).
Corn oil may be called a by-product in starch manufacture, yet the annual value of corn oil is greater than that of cornstarch produced in the United States. It is used in soap and paints. Vulcanized by heating with sulphur, it forms a widely used adulterant and substitute for rubber.
Among the dozens of useful products made from corn are corn meal, corn grits, hominy, breakfast foods, beer, whisky, alcohol, cologne spirits, cornstarch, dextrine, glucose, grape sugar, corn sirup, corn oil, soap, rubber substitute and cattle foods.
A special variety of corn is raised to make cob pipes. Compressed corn pith is packed between the double hulls of warships. Corn husks are used in mattresses and paper is made in very limited amount from the leaves and stalks. Large amounts of popcorn, plain and candied, are eaten in the United States.
Methods of Cultivation.—Owing to its widespread growing, the methods of corn culture vary greatly, and no rigid rules can be laid down for all conditions. For maximum results the cornfield must be rich in humus, its soil finely pulverized, mellow and well drained. Many successful growers in the so-called corn states find these conditions best assured by plowing deeply in the fall, turning under liberal quantities of organic matter such as stable and barnyard manure and leaving the subsoil upturned to benefit from the action of the elements during winter, following with the disk harrow or other like implement in the spring. Planting is done when the soil is thoroughly warmed and when danger of frost is past.
There are two methods of planting commonly practiced, one by drilling or dropping the seed [126] (three or four grains) in hills with a machine drawn by horses and completing two rows at once. The other is planting with an implement known as a lister, dropping and covering one grain in a place in the bottom of a furrow, at intervals of eight to twelve inches. The latter method is quite extensively followed in the more western of the corn states, such as Kansas, Oklahoma and Nebraska. The lister is a plow and planter combined, with moldboards at once turning the soil to the right and left, opening a furrow, dropping and covering the seed at the same time, economizing labor, time and expense. Corn is planted about two inches deep, and if in hills or rows generally three and one-half feet apart each way. A bushel of fifty-six pounds of seed suffices for planting nearly eight acres. For soiling, forage or ensiling it is planted more thickly.
Cultivation, with horse-drawn cultivators, cleaning one row at a time, and by some implements two rows, repeated three or four times in a season, is given to kill weeds, aid in the retention of moisture, and aerate the soil. This begins in many instances before the plants appear, and often in the earlier stages is done with a harrow and later by using the cultivator, upon which the operator usually rides.
Harvesting, done after the grains have become hardened is by cutting the stalks from the hills where grown, by hand or machinery, and standing them in large shocks to be husked later, or, husking the ears directly from the stalks without cutting or shocking. No machine equal to human hands has yet been invented for husking corn. The yield ranges from twenty-five to one hundred bushels of sixty pounds, shelled, or seventy pounds unshelled, per acre. The stalks and husks, whether harvested or not are used as food for live stock, and somewhat in manufactures.
Emmer. See [Spelt].
Johnson Grass (Sorghum halapense) is a coarse perennial, most extensively grown in the South or the Gulf States, for hay. It spreads so persistently and is so difficult to eradicate that its growing is frowned upon by most of the best authorities. One bushel of seed, or thirty-five pounds per acre is about the quantity sown. It is propagated by roots also. Never plant Johnson grass with the expectation of destroying it.