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Seed germinating apparatus used by the United States Department of Agriculture. a, inlet pipe; b, outlet pipe; c, thermo-regulator; d, "guide light" gas delivery tube; e, guide light"; f, opening into water cavity; g,maximum and minimum thermometer; h, thermometer; i, germinating pan; kk. outlets for carbon dioxide. (Yearbook 1894, p. 402.)

477. SOIL FERTILITY IN RELATION TO BARLEY.-Barley is well adapted for pot culture. (432) Where practicable, require each student to apply the following fertilizing ingredients in the rates per acre indicated below. Require the student to calculate the amount of fertilizers required per plat from such commercial goods as may be available in his market. Also require the student to show the method of calculating yields from check plats. See Ohio Bul. 138, p. 40. Make each plat four to eight rods long and the width of one round of the wheat drill. Leave three feet between each plat, and keep this space cultivated so as to prevent growth of weeds. Outer drill row may be cut by hand and discarded in order to get yields similar to those obtained in ordinary practice. Where practicable, each student should be required to carry this trial through from start to finish, calculating fertilizers required, mixing materials from raw goods, applying fertilizers, sowing barley (wheat or oats may be substituted), harvesting crops and calculating yields. Reasons for each of the steps taken should be emphasized.

Place upon the plats commercial fertilizers in quantities equivalent to pounds of elements indicated:

1. None.

2. Phosphorus, 25.

3. Potassium, 25.

4. None.

5. Nitrogen, 25.

6. Phosphorus, 25; nitrogen, 25.

7. None.

8. Phosphorus, 25; potassium, 25.

9. Potassium, 25; nitrogen, 25.

10. None.

11. Phosphorus, 25; nitrogen, 25; potassium, 25. 12. Phosphorus, 50; nitrogen, 25; potassium, 25. 13. None.

14. Phosphorus, 25; nitrogen, 12.5; potassium, 25. 15. Stable manure, 10 loads.

16. None.

17. Stable manure, 10 loads; lime, 1,000 lb.

18. Stable manure. 20 loads.

19. None.

478. COLLATERAL READING.

Cultivated Barleys. By John Percival. Agricultural Botany, pp. 481-492. London: Duckworth & Co. (1900).

Results of Experiments at Rothamsted on the Growth of Barley for more than thirty years on the same land. By J. H. Gilbert. Rothamsted Memoirs, Vol. VI, pp. 1-29. London: Dunn & Chidgey (1890).

Barley. By Wahl-Henius. American Handy Book of the Brewing, Malting and Auxiliary Trades, pp. 449-463. Chicago: Wahl and Henius (1902).

XXIII.

RYE.

479. Relationships.-The commonly cultivated species of rye (Secale cereale L.) has its outer glumes shorter than the flowering glume; while in another species (S. fragiie Biberst) to be found in Hungary and southern Russia, there is a long awn on the outer glume extending beyond the flowering glume. Both species are annual. According to Hackel, the original species (S. montanum Guss) extends from Spain and Morocco to central Asia. It is perennial and the rachis breaks apart upon ripening, both of which characters are lost under cultivation. It is said that rye stubble allowed to stand a long time in the field will sprout again; while this never happens with wheat and barley because the original forms are annual. Rye is more closely related to wheat than to any other cereal, although differing from it in several particulars.

480. The Plant.-When a grain of rye germinates it throws out a whorl of four instead of three temporary roots; a fact which may in some way account for its greater hardiness. Its culms are longer, more slender, and tougher than those of wheat. The rye spikelet is only two-flowered and both flowers develop about equally, making the spike rather uniformly four-rowed. The outer glumes are awl-shaped instead of boat-shaped, as in the case of wheat. The flowering glume is always awned and the keel of the glume is strongly barbed. A rye spike is rather longer than a wheat spike, being usually four to six inches long, not counting the beards. The joints of the rachis are rather farther apart, there being twenty to thirty in a single spike. Unlike wheat, the lower spikelets are fertile and produce

normally sized grains. The organs of reproduction are very similar to those of wheat, except that the anthers in the case of

Rye at blooming: front view of spike on right; side view of portion of spike in middle; on the left, a single spikelet containing two flowers

rye are very much larger. A rye grain is rather longer, more slender, more pointed at the embryo end and more blunt at the upper end. One hundred average grains weigh about 2.5 grams, usually varying between 2.25 and 3.75 grams. In some cases the size of seed may vary so that one and one-half to three and a quarter bushels might furnish the same number

of seed per acre. The furrow or crease is less marked and the surface is more wrinkled. This may be due to the more porous cells of the pericarp. Its general resemblance to an oat kernel has caused rye to be

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about to bloom; shows outer glume, flower- used in adulterating oats ing glume, large anther and palea. when the former is cheaper than the latter per pound. In general the structure of the rye grain is similar to that of the wheat grain, although the starch cells and cells of the aleurone layer appear rather larger in the case of rye.

481. Composition.-Analyses of American rye indicate that the percentage of protein (10.6) and fat (1.7) is somewhat less than that of wheat. The protein contains gluten, and rye flour is therefore adapted for the production of porous bread. The

grain of rye is less variable in composition than wheat, barley or maize. Analyses of American rye flour show the percentage of protein to be very much less than that of wheat flour, being, on an average of four analyses, 6.7 per cent in the case of rye flour, and 10.8 per cent as an average of twenty analyses of wheat flour. The difference in the composition of rye and wheat straw is very slight. It is probable, however, that there is considerable difference in the nitrogen-free extract, since rye straw is much tougher, and recognized to be of little value for feeding purposes.

482. Varieties.-There are very few varieties of rye, probably because rye cross-fertilizes freely. There are both spring and winter varieties, the latter being usually sown. In America, at least, practically no attempt has been made to improve rye either by selection or crossing.

483. Climate.

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- Rye is a hardy plant and stands severe winters better than wheat. It has been matured in Alaska as

1

a winter grain. It does not seem, however, especially influenced by hot weather. It is, nevertheless, naturally a plant of cold climate just as barley is one of warm climate.

484. Soil.-Rye is adapted to light, sandy soil. It has been called the grain of poverty, because it will produce a fair crop on land too poor, or climate unadapted for other cereals. It will thrive on much poorer soils than wheat, maize or barley. This is so well recognized that the expression, "It is too poor to grow rye," is used to indicate the extreme poverty of the soil. Brewer states that the feeling that poor soil and the growth of rye are connected prevents many farmers from raising it for purely sentimental reasons. While fertilization of rye, therefore, is not systematically practiced, the same principles apply to rye as to wheat. (122, 123, 124)

1 Office of Expt. Sta. Rpt. 1903. Sargent: Corn Plants, p. 83.

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