Various crops so selected, planted, and arranged as to

give a constant supply of green forage. As soon as the

early crops are used, they should be resown or others

planted to prevent the land's lying idle. Roots may

assist in autumn.

SUPPLEMENTARY READING

Meadows and Pastures, J. E. Wing.

Farm Grasses of the United States, W. J. Spillman.

Field Crops, Wilson and Warburton, pp. 379-390, 301-306.

Field Crop Production, G. Livingston, pp. 370-380.

Forage Crops, Voorhees, pp. 34-41, 311-327.

Pastures, Meadows, and Soiling Systems 317

Cyclopedia of American Agriculture, Vol. II, pp. 434-456, 569-574.

Reseeding of Range Pasture Lands to Cultivated Forage Crops,

U. S. D. A. Bulletin, No. 4.

Forage Plants, C. V. Piper, pp. 67-113.

U. S. D. A. Farmers' Bulletins:

No. 66. Meadows and Pastures.

72. Cattle Ranges of the Southwest.

102. Southern Forage Plants.

147. Winter Forage Crops for the South.

361. Meadow Fescue.

502. Timothy Production on Irrigated Land in the North-

west.

509. Forage Crops for the Cotton Region.

CHAPTER XXV

SORGHUMS AND MILLETS

The sorghums and millets, a comparatively new and

rather distinct kind of crop, have recently come to notice

in the semi-arid sections of the United States. The

United States Department of Agriculture found them

growing in similar regions of the Old World and intro-

duced them here as worthy of trial. The millets spread

rapidly for a time. The sorghums are now replacing

them slowly but surely save in a few districts.

Both are by nature dry-weather crops, offering possi-

bilities on the dry-farm and even under irrigation. Peren-

nial forage crops are favored in the West largely because

of alfalfa's being so extremely well-adapted. In 3pite of

this, there seems to be a need for annual drouth-resistant

crops.

SORGHUM (HoUms, or Andropogon, Sorghum)

362. Origin. — No one will ever know exactly just

where the group of plants we know as sorghums orig-

inated. Some evidence suggests Africa as the starting

point, but other facts likewise indicate an independent

origin in India. Many wild grasses, closely allied to the

domesticated members of the family, are found growing

wild in Africa — more, in fact, than in any other part of

the world. The sorghums are shown in Figs. 80, 81,

and 82.

318

320 The Principles of Agronomy

As crop-plants, sorghums are as old as any known.

In Egypt they were grown when history was first re-

corded. They soon spread into Asia as far as Manchuria.

Notwithstanding this, the Greeks grew no sorghum;

neither did the Romans until shortly after the Christian

era, when an importation from India took place.

As far as American experience is concerned, the history

of the crop is brief. In 1853 Chinese sorgo (whence the

word as we have it) was brought from France. In 1857,

the United States Department of Agriculture introduced

varieties from every part of the world where much was

grown. The national government also encouraged the

spread and trial of these varieties. Rather constant

development has since followed in the regions adapted

to the particular members of the family brought here,

although the crop has not as yet become a major one. Its

possibilities are potential rather than realized, that is, its

promises are extensive, but its records narrow, on account

of its having had but little chance to prove itself.

353. Relationships. — Sorghums belong to the grass

family, being in many respects closely related to maize.

Johnson-grass (Holcus halepensis) is a bad weed in the

warmer parts of the United States. Vigorous rootstocks

are largely responsible for the pestiferous habits of this

plant. Not all Johnson-grass has rootstocks, since a

few varieties of it are annuals, spreading only by seed.

Then comes Sudan-grass and Tunis-grass, which resemble

Johnson-grass and vary toward the sorghums. All of

these are annuals, lacking rootstocks which cause peren-

nial rooting habits. Sudan-grass seems to occupy a

place of intermediate improvement between Tunis-grass

and the cultivated sorghums.

354. Description. — Corn is so much like sorghum

that by the ordinary person they would be mistaken for

Sorghums and Millets 321

one another in early growth. Their root-systems are

similar save that no brace roots are sent out by sorghum

and that corn roots to a slightly greater depth. Three

to four feet seems to be the commonly accepted depth

for sorghums. An elaborate net-work of roots, however,

occupies the first fifteen to twenty inches of soil.

Sorghum stems are jointed and filled with pith which

in some varieties bears juice rich in sugar. The height

varies from two to a dozen or more feet, but four to eight

feet is common. Ordinary sorghum is usually not less

than one inch or more than two inches in diameter.

Stalks sucker readily, especially if cut before they are

mature.

The leaves are not so abundant as on corn, but they

are thicker and show a decided tendency to roll into

upright cylinders in severe drouths. Rolling probably

lessens transpiration materially by reducing the surface

that is exposed to evaporation. Leaf sheaths, in some

cases, clasp the stem well beyond the next node, present-

ing a more continuous covering than does corn.

After the tasseling period, sorghum differs widely from

maize in appearance and growth habits. No ear develops.

Its tassel flowers are perfect and the grain develops in

the head, which may be a compact, spike-like aggregate

or an open, broom-like panicle anywhere from three to

thirty inches, — sometimes drooping, sometimes erect.

The main stem branches into a number of pedicels,

which branch again. Seed, borne at the end of these,

is rather globular and hard. In color, it varies from

white through yellow, brown, and red to nearly black.

Some kernels are flattened while others are almost spheri-

cal. Some varieties have seed less than one millimeter

in diameter, others nearly a centimeter.

These variations are widest between the types used for

Y

322 The Principles of Agronomy

different purposes. Just as corn varieties fall into six

groups^ or types, sorghum varieties naturally group them-

selves into three distinct types according to the purpose

for which they developed.

366. Varieties. — Though other classifications are often

made, the sorghums are commonly classified as (1) sweet

sorghum, (2) grain sorghum, and (3) broom-corn.

Particularly adapted for sirup, grain, or whisk production,

each type is used for forage and grain. On account of

the comparative infancy of the industry, sorghum pro-

duction has not become nearly so specialized as corn- or

fruit-growing in regard to selection of varieties for different

purposes; yet, there is a general adaptation of varieties

that cannot be ignored.

Sweet, or saccharine, sorghum is grown primarily for

sirup and sugar. For that purpose, sorgo, as it is called,

was brought to the United States. The sudden growth

of the beet-sugar industry, however, offered a more eco-

nomical means of procuring sugar. Shortly afterwards

sweet sorghum proved the most valuable type for forage.

The sweet sap seems to give it a palatability not found