Imágenes de páginas
PDF
EPUB

539. The Grain. – The grain varies from other cereals in being more or less round. The color of the grains is variable, white and red being the more common colors. The color resides in the seed coats. The size and shape of the grain vary largely with the type and variety. The grain of Kafir varieties is larger and rounder than sweet sorghum or broom corn varieties.

540. Composition.—Compared with the grain of maize, sorghum seed contains a somewhat smaller percentage of protein and about one-half the percentage of fat. Otherwise they are quite similar in composition. Sorghum fodder is distinctly lower in protein and higher in crude fiber than maize fodder. All varieties of sorghum contain some sugar, varying from two to twenty per cent of the juice, or from 1.2 to twelve per cent of the cane. Those varieties which contain sufficient sugar, say ten per cent, in juice, for the practical manufacture of sirup or

ties are known as nonsaccharine varieties.

541. Varieties.—Large number of varieties of sweet sorghum have been tested in this country, particularly with reference to their value for the production of sirup and sugar. Among these varieties are two rather well marked types: the amber canes and the orange canes, the former of these being rather more early maturing than the latter. These are also recognized as desirable varieties for forage purposes. Early amber, extra early; Folger's, early; Colman, medium; and Collier, late, are recommended for this purpose as well as for the manufacture of sirup. Among the varieties grown for seed the principal ones are known as Kafir corn, of which three varieties are recognized : red Kafir, white Kafir and black hulled white Kafir (synonym African millet). In the red Kafir the seed is red or light brown, while in the white Kafir the seed is white. The hulls are gray or greenish white, while in the black hulled white Kafir the hulls are gray, brown or black. In both the white varieties the hulls are hairy and larger than in the red variety,

where the hulls (glumes) are small, thin and brown, covering less than half the grain. The seed of both white varieties is less astringent and more palatable than the red variety. At the Kansas Station the red and black hulled white varie

ties have given the largest yields; while at the Oklahoma Station the white varieties have given the best results. Up to the present time the red variety has been most generally grown,

[graphic]

A, Sorghum: type, standard broom corn. (After Hartley.) B. Sweet sorghum :

variety, amber cane. (After Denton.) C. Kafir corn: variety, black hulled white. (After Georgeson.)

but the culture of the black hulled white variety is being rapidly extended. While the Kafir varieties have the widest adaptation and are most largely grown, durra (synonyms Indian millet, Egyptian corn), milo maize, Jerusalem corn and Egyptian rice corn are also grown, the latter two being especially adapted to higher altitudes and arid regions.

* These are very similar to Kafir-corn in many respects, and in growing, harvesting and feeding practically the same methods may be followed. The white milo maize grows a head very similar to Kafir-corn, is a heavy yielder of fodder, but

requires a full and favorable season for maturing, and is often damaged by frost on this account. The yellow milo maize, or ‘Brown Dhura,' does not require so long a season, and is a heavy yielder of grain, the head hanging down on a short gooseneck, when ripe. The crooked heads, which hook and cling to everything they touch, are a great hindrance in handling. The seed also shells badly when ripe. Rice-corn and Jerusalem corn are very similar in their growth, the heads of both hanging down, ard annoying in the same way as those of the yellow milo maize. The seed of Jerusalem corn, being slightly flattened when ripe, can be distinguished from that of the rice-corn, which is round and also lighter in color. The two will mature in a short season and produce from twenty-five to fifty bushels of seed. They are adapted to the higher, cooler and drier counties of the western part of the state. They are very productive of seed, but the fodder yield is very light. In the eastern part of the state the English sparrow is a great pest where grain is raised. The seed is somewhat sweeter than the Kafir-corn grain, which they bother very little." 1

Broom com is divided into two types: the standard and the dwarf. Standard broom corn grows from ten to fifteen feet high, bearing a panicle of brush from eighteen to twenty-eight inches long; while the dwarf grows from four to six feet high and bears a brush of finer quality from ten to eighteen inches long, with occasionally strains that produce brush as long as two feet. The product of the dwarf variety is used for making whisk brooms and other brooms of small size; while that of the standard sort is used for making ordinary carpet brooms. The dwarf varieties have a larger amount of foliage, are better adapted to stand drouth, and for cultivation on sandy soils. Kafir varieties usually grow from four to seven feet in height; while sweet sorghum varieties usually range from eight to ten feet in height.

542. Improvement of Varieties. The wide variations in the cultivated forms of sorghum suggest that the varieties might be easily improved or modified by selection, provided they are kept from crossing. Hartley has shown that broom corn and sorghum will readily cross and produce intermediate forms when grown in adjacent fields. The different forms may become

[ocr errors]

injured by such crossing, thus making it desirable to exercise care with regard to the source of seed used for planting. The maintenance of a seed patch grown from seed selected from the best plants of the seed patch of the previous year is to be recommended here, as with other cereals. This is particularly true in the case of broom corn, inasmuch as there is considerable variation in the brush of different plants, crooked and thick centered brushes greatly reducing the value of the product. These forms are probably hereditary and, if so, could be eliminated in the course of time by selection, although it would doubtless take some time on account of the influence of crossing. Hartley suggests that it might be possible to produce a saccharine variety of broom corn, thus securing a variety that would produce both broom and sirup. For the production of grain, Kansas prefers long closely compact heads.

543. Germination. The germinating power of sorghum is very likely to be low, and poor stands are very common because the grain, even though it has been thoroughly dried, is liable to absorb sufficient water in damp weather to produce fermentation. Grain intended for seed should, therefore, be left in the heads until planted. The heads may be either hung up separately or kept in loose piles in a dry, well-aired place. Testing the germination power is important and seed that is less than ninety per cent should not be used.

II. CLIMATE AND SOIL 544. Climate.-Sorghum is especially adapted to a climate that is both hot and dry.

"Perhaps the strongest recommendation of Kafir corn lies in the fact that it will produce a crop on less rain than is required for corn, and that it is not affected so disastrously by hot winds. It is, therefore, especially adapted to the semiarid West, where corn succeeds only one in five or six years because of hot winds and drought. It is owing chiefly to this quality that its culture has spread so rapidly in Kansas and Oklahoma. Hot winds are the main cause of the failure of the corn crop in this region, and they are never more destructive than when they happen to come when the corn is tasseling. They cause the pollen to dry up, and the silk is not fertilized. Even with a sufficient rainfall, a few days of these withering blasts from the southwest, in tasseling time, may reduce the yield of corn fifty per cent. Kafir corn is not affected in the same way. Fertilization takes place more readily and the whole plant is better adapted to stand dry weather. The leaves are thicker and coarser than corn leaves, and do not dry out so readily; they are closer together and partly protect each other, and the plant is not so tall and, therefore, not so much exposed. When corn has once been stunted by drought or hot winds, it never recovers. Not so with Kafir corn. It may remain stationary and curled for days and even weeks, but when the hot winds cease and rain comes it will revive and, if not too late in the season, will still produce a crop of grain.” 1

It is necessary to distinguish between possible climatic range and the economic climatic range of sorghum. While sorghum can be grown in almost any climate in which maize can be grown, its economic climatic range does not extend north of the fortieth parallel.

545. Soil. The soil requirements of sorghum are similar to those of maize, although the Kafir varieties are believed to succeed on land too poor to raise the latter. The plant also seems to be rather more resistant to alkali. For its best development, broom corn requires rich soil. Ordinarily it would not be wise to attempt to raise it on any but the best maize lands, although river bottoms are usually not desirable on account of the weeds. Dwarf broom corn succeeds best on dry, sandy soils, the brush having a tendency to grow coarse on the richer soils. The same principles apply in the use of fertilizers as in maize. (285-294)

546. Rotation.-Ordinarily sorghum takes the same place in the rotation as maize. It is a general experience that a crop following sorghum, particularly the Kafir varieties, is not so good as one following maize. The reason for this appears to be that the sorghum being more resistant to drouth continues to grow and thus exhaust the soil of its moisture, and possibly its plant food, when the maize would be prevented from doing so. The land thus breaks up hard and lumpy after the sorghum. As a

1 U. S. Dept. of Agt, Farmers' Bul. 37, p. so

« AnteriorContinuar »