Imágenes de páginas
PDF
EPUB

9 Rust: leaves, per cent — -; culms, per cent 10. Smut: loose, per cent

; stinking, per cent II. Spike: erect; leaning; nodding. 12. Spike: beardless; partly bearded; bearded. 13. Shattering: badly; medium; none.

200. MATURE DRIED PLANT IN LABORATORY, Give each student a printed or typewritten sheet as indicated below and request a description of two or more varieties from dried samples by underscoring the adjective which most nearly applies to the condition found. If opportunity to study varieties in the field is lacking, some of the items given in (199) may be included here. 1. Length of spike: average of five spikes from base of lower spikelet to tip of

apical flowering glume, not counting awn, if any — 2. Compactness of spike: very open; open; medium; compact; crowded. 3. Shape, side view: tapering towards apex; tapering both ways; uniform;

clubbed. 4. Shape, end view: square; flattened with spikelet; flattened across spikelet. 5. Sterile spikelets: No. — 6. Awns: length 7. Awns: slender; medium; stout. 8. Awns: parallel; spreading; widely spreading. 9. Awns: deciduous; partly deciduous; persistent 10. Awns: light yellow; yellow; brown; black. 11. Spikelet: spreading widely; spreading; narrow. 12. Spikelet: number of grains 13. Basal hairs: long; medium; short; wanting: white; brown 14. Outer glume: light yellow; yellow; bronze; black. 15. Outer glume: hairy; partly hairy; smooth. 16. Width of outer glume: broad; medium; narrow. 17. Length of outer glume: long (as flowering glume); medium; short 18. Attachment of outer glume to rachilla : firm; medium; weak. 19. Beak of outer glume: long; medium; short. 20. Shoulder of outer glume: broad; medium; narrow: square; sloping; round.

201. The GRAIN. Give each student a printed or typewritten sheet as indi. cated below and request a description of two or more varieties by underscoring the adjective which most nearly applies to the condition found.

1. Density: very hard ; hard; medium; soft; very soft.
2. Appearance of cross-section: very horny; horny; dull; starch.
3. Weight: of 100 average seeds in duplicate (a)

(b)
4. Ratio of length to width: divide length of twenty-five grains by width of

twenty-five grains with crease down -
5. Shape: straight; curved; pear-shaped.
6. Plumpness: plump; medium; shrivelled.
7. Cheeks: flat; plump; angular.
8. At tip: pointed; blunt.
9. At base: pointed ; blunt.

10. Crease: deep; medium; shallow: wide; medium; narrow. II. Brush: large area; small area: long hairs; short hairs.

12. Color of grain: light yellow; yellow; clear amber; dull ambxr; clear red; dull red.

202. CLASSIFICATION OF VARIETIES OF COMMON WHEAT. Take preferably fifty varieties of either spring or winter wheat in sheaf and in grain. A desirable plan is to have one thousand grains of each variety in glass vials one inch in diameter and six inches high, taking care to have the vials of clear glass and uniform diameter. The difference in the size of grains can be noted at a glance and all other characters as easily observed as in larger samples.

[ocr errors][ocr errors][merged small][ocr errors][ocr errors][ocr errors][merged small][ocr errors]

An agronomy laboratory, showing materials ready for the study of varieties of wheat.
Require the student to classify them into eight groups as follows:

S Grains red
(Glumes white
Bearded

Grains white
(Glumes bronze

Grains red
1 Grains white

Grains red
(Glumes white

Grains white
Beardless

( Grains red
(Glumes bronze

7 Grains white The student should note what differences, if any, exist between varieties of the same group as for example in smoothness or hairiness of glumes, and length of straw; and in what cases the varieties are probably synonymous. (89) A written report concerning the best ten varieties as shown by Stations testing varieties in

question may be required. Definite references to proper bulletins should be tur. nished each student.

203. RelatION OF COLOR, HARDNESS, SIZE, Specific GRAVITY AND CON TENT OF GLUTEN.

1. Take five varieties of wheat varying as widely as may be in different quali. ties mentioned, as for example, Fultz, Gold Coin, Rudy, Turkey, Kubanka.

2. Note color and hardness.
3. Find weight of 500 grains.

4. Fill a 50-gram picnometer with benzene and weigh on balance sensitive to I mgm. Add twenty grams of wheat and weigh. Add weight of wheat to weight of picnometer and benzene and subtract last weight, which will give weight of volume of benzene equal to volume of grains of wheat. Divide this difference by the specific gravity of benzene, which will give the weight of a volume of water equal to the volume of grains of wheat. To determine the specific gravity of the wheat, divide twenty grams of wheat by the weight of an equal volume of water. 5. To find the relative size of grains, divide the weight of five hundred grains

by their specific gravity.

6. To determine content of gluten, take thirty grams of ground wheat, work with water in a round bottomed glass vessel with spatula, and wash off starch after gluten has gotten into a sticky mass, and continue to wash until there is no appearance of starch grains being carried off. To be sure that all the starch is freed from gluten, test washings with potassium iodide; blue color shows the presence of starch. Work mass of gluten in fingers until all water that will run off has been expelled. Weight will give amount of moist gluten. Place in drying oven at 110° C until constant weight is obtained. Weight will give amount of dry gluten At same time find weight of dry matter in ten grams of ground wheat.

Calculate per cent of moist and dry gluten from data Snyder's apparatus for de obtained. termining the granulation

If there is not time or facilities to carry out No. 6, of flour. 1. Erlenmeyer flask; 2, suction connec.

the instructor may determine the content of gluten in tion: 3. rubber cork: 4. advance and allow the student to compare Nos. 2 to adapter; 5, rubber (tube) 5 with the results thus obtained. packing, making air-tight 20

204. QUALITY OF FLOUR.-Furnish each student joint; 6, section of brass

with a sample of high grade and low grade flour and Crucible overlapping sec

have him determine the following: tion 7; between these two nav parts bolting cloth is 1. Character of granulations: Note under a high placed and removed as de- power microscope (172) whether flour particles are round sired-any size cloth can or angular. be inserted; 8, wire clamp 2. Size of particles: By means of apparatus deholding apparatus in place. vised by Snyder, determine the amount of flour in twenty-five grams that will pass through bolting cloth Nos. 9 to 20.

3. The color test: Place samples of flour on plate of glass and determine color by means of a series of colored glass slabs.1

4. The baker's sponge test: Place in a wide pint porcelain bowl one hundred grams of flour. Dissolve five grams of sugar and five grams of compressed yeast in sixty-five grams of water and stir with steel spatula into flour. Continue to add water and knead until proper consistency is obtained. Note quantity of water required to give equal consistency in both samples. Place dough in cylinders about four inches in diameter graduated into c. c.'s. Set tube in water at 90° F. and determine time required to rise to full height and maximum volume attained. If time permits, allow second rise to occur and note time and maximum volume. The first rise takes about an hour and a half to two hours and the second rise from an hour to an hour and a half. If the per cent of gluten has been determined (203), calculate volume to each gram of gluten.)

205. COLLATERAL READING.

The Basis for the Improvement of American Wheats. By Mark Alfred Carleton. U. S. Dept. of Agr., Div. of Veg. Phys. and Path. Bul. 24, pp. 63-83.

The Structure of the Wheat Grain. By Charles E. Bessey. Neb. Bul. 32, pp. 100-114

William C. Edgar: The Story of a Grain of Wheat, pp. 111-131. New York: D. Appleton & Co.

Plant Breeding. Willet M. Hays. U. S. Dept. of Agr., Div. of Veg. Phys. and Path. Bull. 29, pp. 44-54.

Grain Elevators. By N. A. Cobb, Dept. of Agr., Sidney, New South Wales, Misc. Pub. 452.

| These can be purchased of Eimer & Amend, New York.
* For further details see Minn. Bul. 62. (1899), pp. 346-352.

VIII.

MAIZE.

1. STRUCTURE 206. Name.-Columbus found Zea mays L. cultivated on the Island of Hayti, where it was called mahiz; hence the name maize. Mahiz, or marisi, is said to be an Arawak Indian word of South American origin. The word corn is used in Furope as a generic term for all cereals, and originally the wory meant any hard edible seed, grain or kernel. In England úr ear of corn means a head or spike of wheat. Naturally, theret zre, the colonists, finding maize cultivated abundantly by the Indians, applied the term Indian corn to distinguish it from other corn. In the United States corn is everywhere understood to mean maize and a Pennyslvania court has ruled that the word corn is a sufficient description of Indian corn. In Latin America “maiz" is the term generally used.

207. Fodder, Stover and Silage.- Fodder, when applied to maize, is the plant, including the ears, which has been cut and field cured without regard to the manner or thickness of planting or stage of maturity. Stover is the residue after the ears have been removed from the fodder. When the whole plant or the residue after removing the ears is placed without curing in the silo, the resulting material is called silage.

208. Relationships.—The tribe (Maydeae) to which maize (Zea mays L.) belongs differs quite widely from the tribe (Hordeae) to which wheat, rye and barley belong. In the same tribe with maize belong teosinte (Euchlaena mexicana Schrad.), a sub-tropical plant sometimes cultivated in the Southern States

1 Harshberger, J. W.: Maize; A Botanical and Economic Study, p. 88.

« AnteriorContinuar »