pound of grain to two and one-tenth pounds of straw when fertilizers were used, and one of grain to two of straw when no fertilizers were used. The Illinois Station has found as high as two and seven-tenths pounds of straw per each pound of grain, and as low as one and two-tenths pounds in different seasons under otherwise like conditions." Kansas Station found a variation of from four and one-tenth to one and two-tenths pounds of straw to one pound of grain due to season. In general, the more favorable the season the more fertile the soil, and the later the variety or the later the seeding the greater is the proportion of straw to grain.

4

379. Inflorescence.—A typical panicle is nine to twelve inches long, contains from three to five whorls of branches and bears about seventy-five spikelets. The branches arise from alternate sides of the rachis and vary in length and position; thus the panicle may be open or closed; symmet

A spikelet of oats:, 1, outer glumes; 2, lower flower; 3, upper flower; 4, rudiment of third flower

rical or one-sided. Each spikelet is at the end of a flexible pedicel of variable length. The spikelet contains two or more flowers; only two usually mature, the lower one always developing into the larger grain. The outer glumes are membraneous and considerably larger (three-fourths to one inch) than the flowering glume. The color of the latter varies from yellow to reddish brown and black. The flowering glume of the lower flower usually partially encloses that of the upper flower. The awn, when it occurs, is on the back (not at the tip) of the flowering glume, and usually occurs only in the lower flower of the spikelet. The palea is smaller than the flowering glume and enclosed

1 Ohio Rpt. 1896, p. 142.

2 Jli. Bul. 12 (1890), p. 355. 8 Ill. Bul. 31 (1894), p. 384.

4 Kan. Bul, 42 (1893), p. 83.

within the latter.

to those in wheat.

P

t

The organs of reproduction are quite similar (56)

380. The Grain. The oat kernel, except in hull-less varieties, remains enclosed in the flowering glume and palea. These parts are usually referred to as the oat hull, but are entirely different from the hull of maize (228) or the bran of wheat. (64) In this book the caryopsis of the oat will be called the kernel, and the kernel plus the hull will be called the a grain. In general form and structure the oat kernel is similar to the grain of wheat, but is rather more elongated, while the pericarp is characterized by its hairy surface. Richardson found in an average of 166 varieties that 100 grains weighed 2.5 grams, with variations from 1.75 to 3.75 grams per hundred grains.1

Magnified section of

t, testa; a, double

sperm with com

381. Relation of Hull to Kernel. The quality of oats depends principally upon the proportion of hull to kernel. The per cent of hull depends portion of oat ker- both upon the variety and upon the conditions nel: pericarp of growth, varying from at least twenty to fortyrow of aleurone five per cent. American varieties contain on an cells; 5, endo- average about thirty per cent of hull and seventy pound starch per cent of kernel. It has been demonstrated grains. Nucellus that there is no necessary relation between section. (After weight per bushel or shape of grain and the per cent of kernel or food value. The Illinois Station, working during five years with from thirty to sixty varieties, the seed of which was from various sources, but the crops all grown under like conditions, found that generally varieties with long, slender, comparatively light grains had the largest per cent of kernel. The Ohio Station, working with seventy varieties

not shown in this

Pammel.)

1 U. S. Dept. of Agr., Div. of Chem. Bul. 9. 2 Ill. Buls. 7, 12, 19 and 23.

one season, found that the Welcome or short, plump grain group (385) contained a higher percentage of kernel than the Seizure group, which has longer and more slender grains. While in the Welcome group the varieties with the highest weight per bushel contained the highest per cent of kernel, the reverse was the case with the Seizure group.1 Saunders believes that the results at Ottawa prove that with a given variety the actual weight of hull per grain is the same without reference to the weight per bushel.2

Since the hull (flowering glume and palea) develops long before the kernel, it would seem that with a given variety any unfavorable environment which prevents the grain from filling fully would both decrease the per cent of kernel and the weight per bushel. If, however, a large number of varieties are grown under the same conditions, it is probable that those varieties best suited to the environment would develop their kernels most completely and thus have the highest per cent of kernel. Thus the per cent of kernel might in some instances be the highest in varieties with short, plump grains, and in other instances in those with long, slender ones, depending upon their adaptability to the given region or season.

382. Weight per Bushel.—The legal weight per bushel in all States of the United States is thirty-two pounds, except in Idaho (thirty-six), Maine, New Jersey, Virginia (each thirty) and Maryland (twenty-six). In Canada it is thirty-four pounds. Oats may vary in weight from twenty-five to fifty pounds per bushel, the lighter weight being found in the more southern climates. Richardson found the average weight per bushel of 166 varieties gathere from various sections of the United States to be thirtyseven pounds. In order to increase the weight per bushel and consequently the commercial quality, elevators frequently resort to a process known as clipping.

1 Ohio Bul. 57, p. 108.

2 Can. Farms Rpt. 1903, p. 8.

383. Composition. The average of American analyses is as follows:

Rather wide variations are found in the composition of the oat grain, due doubtless to the variation in percentage of hull, since the composition of the oat kernel shows only moderate variations. Taking the grain as a whole, oats differ from maize principally in having a larger per cent of crude fiber at the expense of starch. The kernel is richer in protein and fat than the corresponding part of any of our other cereals. Oat straw has a higher percentage of protein and a lower percentage of crude fiber than wheat or rye straw. The composition of oat hay cut when the grain was in the milk is very similar to that of timothy hay.

No coherent substance similar to gluten in wheat is to be obtained from the oat kernel; hence light bread cannot be made from it. Osborne has found that the proteids of the oat kernel undergo great changes when brought in contact with water or sodium chloride solution. It is necessary, therefore, to distinguish between the primary and secondary proteids of the oat kernel. Of primary proteids, the oat kernel contains about one and one-fourth per cent of an alcohol-soluble proteid; about one and one-half per cent of salt-soluble proteid or globulin, while the rest of the proteids contained in the oat kernel is an alkali-soluble body. This substance which forms the larger portion of the proteids has been given the name avenine, 1

1 Memoirs National Academy of Sciences, Vol. VI, p. 51; also Conn. Rpt. 1891, P. 134.

384. Germination.-Saunders has reported the average germination of four samples of oats during six years as follows: 9o, 93, 78, 67, 54 and 30 per cent. The viability was greater than with wheat, barley, peas or flax.1 Kinzel found that the percentage of germinable seed steadily increased for eight to ten months, after which there was a decrease.' The Ohio Station found an average yield during five years of forty-eight bushels per acre where seed of the previous year's growth was used, and forty-five bushels per acre where seed was one year older.

The Wisconsin Station reports that soaking oats in a solution of two and one-half parts of formaldehyde to 1,000 parts of water decreased germination from six to seventeen per cent.1 An increased yield has been observed in some instances from hot water and potassium sulphide treatment beyond that resulting from replacing smutted panicles with sound ones. This may be explained by supposing that many plants are attacked with smut without developing spores when seed is not treated, and by its possible higher germinative energy. Kellerman found that treatment with hot water and potassium sulphide generally caused better and greater germination; while the Wyoming Station found copper sulphate, hot water and potassium sulphide generally injurious.

385.

III. VARIETIES.

Classification.—There are spring and winter (fall) varieties of oats. The winter varieties are principally grown south of the southern boundary of Virginia, Kentucky, Missouri and Kansas, or about 37° N. Lat., where they are the chief

1 Can. Expt. Farms Rpt. 1903, p. 44.

2 Landw. Vers. Stat. 54 (1900), No. 1-2, p. 123

3 Ohio Bul. 138 (1903), p. 48.

4 Wis. Rpt. 1902, p. 268.

Ohio Bul. 3 Tech. ser. (1893), p. 201.