Field crop production; a text-book for elementary courses in schools and brief courses in colleges

Front matter

Edited by L. H. BAILEY

Mann, Beginnings in Agriculture.

Warren, Elements of Agriculture.

Preface

This book is intended to supply in convenient form general information regarding the subject of field crops, for use in agricultural schools and in elementary courses in colleges. It is in no sense a complete or exhaustive treatise on the subject, such as would be desired for regular college courses in field crops.

In the author's judgment, the most effective method of presenting the subject of field crops to students in elementary courses is by the combination textbook and lecture plan, the textbook to furnish basic information, and the lecture to include such specific information as the instructor cares to give. In very elementary courses, the textbook would probably furnish the principal source of instruction. In presenting the subject of field crops to students of short or two-year courses in agricultural colleges, it is necessary, on account of the vast amount of experimental data which is accumulating and constantly changing, to devote a large part of the time allowed to the course to information of this sort, which leaves but little time for presenting the more elementary phases of the subject. A more complete and satisfactory course can, in the author's opinion, be given if the student by the aid of a general textbook can acquire these elementary facts outside of class hours. The elementary courses may be made very complete, if desired, by the use of such a textbook, and the devoting of the major part of the lecture vi PREFACE

periods to the consideration of experimental results in general, to the making of local applications and the applying of the principles of plant physiology and plant-breeding to field crops.

Many students in field crop courses, both in agricultural schools and colleges, have come from town or city homes, and have had little or no farm experience. While it is not possible to acquire farm experience from a textbook, it is possible to gain from such a source much of the general information which is lacking.

In the writing of this book there has been included but little statistical matter and but little experimental data, which can be presented in a more up-to-date form by means of lectures. As the book was originally written, it contained some discussion of all of the North American field crops, but in order to keep it within a reasonable size, it has been necessary to omit some of them, the most important of which are sugar cane and tobacco.

The author has observed, first as a student and later as an instructor, that the interest which the student feels in any subject depends largely upon whether or not the subject matter is presented in an attractive manner. For that reason he has included in this book somewhat in detail some facts which are of interest but not generally considered of vital importance.

It is hoped that this book will prove useful as a general textbook of field crops in elementary courses, and as a supplementary textbook in other courses, for students with little or no elementary knowledge of the subject.

I am indebted to C. G. Williams and F. A. Welton of the Ohio Experiment Station, to Professor E. G. Montgomery and Dr. H. H. Love, of Cornell University, to C. R. Ball and Dr. C. E. Leighty, of the U. S. Department of Agriculture, and to Professor H. D. Hughes, of Iowa State

PREFACE vii

College, who have read the manuscript in whole or in part and who have offered many helpful suggestions. I am grateful to those who have written chapters which have been included in the text, and which appear under their names, and to those who have furnished illustrations, to whom credit is given in the list of illustrations. I wish also to express my appreciation to my wife, Inez Van Sickle Livingston, for her constant assistance in preparing the manuscript for the press.

GEORGE LIVINGSTON.

Ohio State University, CoLUMBL's, Ohio.

Chapter I

Classification of plants, 2 — Variety, 3 — Genus, 4 — Naming of plants, 5 — The family, 5 — Order, class, and division, 6 — Length of life, 7 — Cultivated plants, 8 — Field crops, 8 — Classification of field crops, 9 — Definition of terms, 12.

chaptp:r II

Rotation experiments at Rothamsted, 15 — Rotation experiments in Iowa and Illinois, 17 — Rotation experiments in Ohio, 18 — Why rotations give better yields, 20 — Planning a rotation, 23 — Rotation does not maintain fertility, 25 — Suggested rotations, 27.

Chapter III

Historical, 29 — Botanical characteristics, 30 — Root, stem, and leaves, 30-33 — Flowers, ear, and kernel, 34- 37 — Ancestors of the corn plant, 38 — Types of corn, 41-50 — Uses of corn plant, 50-53 — The world's production, 54 — Adaptation, 57.

CHAPTER IV Corn or Maize {Continued) ...... 59-98

Methods of culture, 59 — Plowing and preparing the land, 61-67 — Testing the seed, 68 — Time, depth, and

ix

TABLE OF CONTENTS rate of plantinG:, 71-74 — Cultivation, 75 — Harvesting and storing, 76-82 — Improvement of corn, 82 — Variety test, 83 — Seed selection, 85 — Ear-to-row test, 88 — Breeding and multiplying plot, 90-91 — Corn judging, 92

— Insects and fungous diseases, 93-98.

Chapter V

Historical, 99 — Botanical characteristics, 100 — Root, stem, and leaves, 100-103 — Spikelets, flowers, and kernel, 103-106 — Types of wheat, 107-113 — Uses of wheat, 113 — Evolution of flour mill and modern milling, 114- 119 — The world's production, 119 — Production in the United States, 121 — World's supply and demand, 122

— Wheat districts of the United States, 123-126 — Adaptation, 127 — Methods of culture, 129-136 — Improvement of wheat, 136 — The variety test, 137 — The head-row test, 139 — Wheat judging, 141 — Insects and fungous diseases, 142-144.

Chapter VI

Historical, 145 — Botanical characters, 145 — The leaves and flowers, 147 — Types of oats, 150 — Uses of oats, 150-152 — The world's production, 152 — Production in the United States, 152 — Exports and imports, 153 — Adaptation, 154 — Methods of culture, 155-160 — Improvement of oats, 161 — Insect enemies and fungous diseases, 162.

Chapter VII

Historical, 164 — Botanical characters, 165-166 — Types of barley, 167 — Uses of barley, 168-170 — The world's production, 171 — Exports and imports, 172 — Adaptation, 172 — Methods of culture, 173-175 — Insect enemies and fungous diseases, 176.

TABLE OF CONTENTS XI

CHAPTER yill

Historical, 177 — Botanical characteristics, 177 — Uses of rye, 178 — Production, 180 — Adaptation, 181 — Methods of culture, 182 — Fungous diseases and insect enemies, 183.

CHAPTER IX Rice and Buckwheat ....... 184-193

Rice: Historical, 184 — Botanical characteristics, 184 — Uses, 185 — Production and distribution, 186 — Adaptation, 187 — Cultural methods, 188 — Buckwheat : Historical, 180 — Description, 180 — Uses, 101 — Production, 101 — Cultural methods, 102.

Chapter X

Timothy: Description, 104 — Distribution and adaptation, 10() — Cultural methods, 107-200 — Kentucky blue-grass : Description, 201 — Distribution and adaptation, 203 — Uses, 204 — Cultural methods, 205 — Canada blue-grass, 206 — Redtop : Description, 206 — Adaptation and distribution, 208 — Uses, 208 — Cultural methods, 209.

Chapter XI

Orchard grass : Description, 210 — Distribution and adaptation, 211 — Uses, 211 — Cultural methods, 212 — Brome-grass, 212-215 — The fescues, 215-217 — Bermuda-grass, 217-218 — Johnson-grass, 219 — The ryegrasses, 210.

Chapter XII

Annual Grasses for Grain and Forage .... 221-238 The millets : The foxtail millets, 221-224 — The broomcorn millets, 224 — The barnyard millets, 225 — Pearl xii TABLE OF CONTENTS millet, 226 — Uses of millets, 226 — Cultural methods, 227 — The sorghums : General description, 228 — Saccharine sorghums or sorgo, 229-232 — The non-saccharine sorghums, 232-235 — The broomcorns, 235-238.

CHAPTER XIII Legumes in Genehal ........ 239-252

Description, 239 — The flowers, 240 — Pollination, 242

— Relation to soil fertility, 245 — Bacteria in relation to legume, 247-250 — Inoculation, 250.

Chapter XIV

Historical, 253 — Red clover : Description, 254-256 — Distribution and adaptation, 256-258 — Uses, 258 — Cultural methods, 259-263 — Mammoth clover : Description, 264 — Uses and cultural methods, 264-266 — White clover: Description, 266 — Adaptation and uses, 267 — Cultural methods, 268 — Alsike clover : Description, 269

— Adaptation, 270 — Uses and cultural methods, 270-

272 — Crimson clover : Description, 272 — Adaptation,

273 — Uses and cultural methods, 274-276 — Fungous diseases and insect enemies, 276.

Chapter XV

Description and varieties, 279-281 — Distribution and adaptation, 282-283 — Use of alfalfa, 285 — Cultural methods, 286-292.

CHAPTER XVr

The Vetches, Sweet Clovers, and Others . , . 294-304 The vetches, 294-297— The sweet clovers, 298-301 — Bur clovers, 302 — Japan clover, 303.

TABLE OF CONTENTS

XlU

CHAPTER XVII LEGuaiEs FOR Grain and Forage

The soybean : Description, 305 — Distribution and adaptation, 307 — Uses and cultural methods, 308-312 — The cowpea : Description, 312 — Distribution and adaptation, 314 — Cultural methods, 315 — The field pea: Description, 316 — Distribution and adaptation, 317 — Cultural methods, 318 — The field bean, 320 — The peanut, 321.

CHAPTER XVIII Root Crops and Related Products

Introductory, 323 — The sugar beet, 324-328 — Mangel wnrzels, 329-330 — Turnips and rutabagas, 331 — The carrot, 332 — Rape : Description, 333 — Distribution and adaptation, 333 — Uses, 334 — Cultural methods, 335.

305-322

323-336

CHAPTER XrX

The Fiber Crops ........

Cotton : Description, 339 — Kinds of cotton, 341 — Marketing and uses, 343 — Production and adaptation, 345 — Methods of culture, 348 — Flax : Description, 351 — Uses, 352 — Production and distribution, 354 — Cultural methods, 355 — Hemp, 356.

337-357

CHAPTER XX ^HE Potato 358-369

Production, 358 — Description, 359 — Cultural methods, 360 — Sprouting and planting, 361-362 — Varieties, 363 — Harvesting and storing, 366 — Insects and fungous diseases, 366-368.

Chapter XXI

Meadows and pastures as field crops, 370 tion, 371 — Grass mixtures, 372

The rota- Testing the seed, 374 xiv TABLE OF CONTENTS

— Seeding, 377 — Care of grass lands, 377 — Temporarypastures, 370 — Substitute hay crops, 380.

CHAPTER XXII The Marketing of Grain 381-395

Supply and demand, 381 — The country elevator, 382

— Cooperative and line elevators, 383 — The terminal market, 384 — Grain inspection and methods employed, 386 — Methods of sale, 389 — The price of grain, 392 — Export trade, 394.

Appendix

List of Experiment Stations ...... 399

Composition of Field Crops ...... 400-401

LIST OF ILLUSTRATIONS

Small plots of cereals at the Dominion of Canada Experimental

Farms, Ottawa Frontispiece

FIGURE PAGE

1. Comparative value of crops in United States ... 9

2. Six leading crops of United States 11

3. Flowers of the corn plant. (Extension Department, Ohio

4. Ear of dent corn with small ears clustered at base . . 39

5. A branching corn plant . 40

6. Cross section of a kernel of dent corn ..... 42

7. An ear of dent corn ........ 43

8. Cross section of a kernel of flint corn ..... 44

9. An ear of flint corn 45

11. Cross section of a kernel of soft corn ..... 47

12. An ear of soft corn ........ 48

13. An ear of sweet corn ........ 48

14. An ear of pod corn. (Extension Department, Ohio State

15. Unfertilized and fertilized corn plots ..... 60

16. Plowing with a tractor. (^Country GentJeman) ... 62

17. A field of corn destroyed by grub worms .... 64

18. Rye plowed under. (Extension Department, Ohio State

19. A good type of roller for crushing clods. (Extension Depart-

ment, Ohio State University) 67

20. Making a germination test. (Extension Department, Ohio

21. Planting corn with a check rower 73

22. Harvesting corn with a corn binder. (International Har-

vester Company) 78

23. Filling the silo 79

XV

XVI

LIST OF ILLUSTRATIONS

FIGU

RE

A

34 35 36 37 38 39 40

41. 42.

43. 44.

48. 49.

(Agronomy Department, Ohio (Extension Department, Oliio (Agronomy Department test field of corn in shock, Station) .

25. A rack for storing corn.

State University) .

26. Remnants of an ear-row

Oliio Station) ........

27. Corn-breeding plot

28. Corn-multiplying plot .......

29. A sample of show corn .......

30. Diagram showing manner of growth ....

31. Diagram showing stooling or tillering in wheat

32. Variation in number of culms per plant. (Agronomy De

partment, Ohio Station)

33. Variation in size of head and number of spikelets. (Ohio

Station) .

A spikelet of wheat

Einkorn

Spelt

Emmer .

Club wheat

Polish wheat

Loaves of bread illustrating the baking qualities of flour made from different varieties of wheat. (Extension Department, Ohio State University) . . . ,

"Wheat crops of the leading countries of the world

Cross section of a poorly and well prepared seed bed. (Extension Department, Ohio State University) .

Harvesting wheat. (Dr. C. E. Saunders, Ottawa, Canada)

A combination harvester and thrasher. {Successful Farming)

Thrashing wheat in the Northwest .....

Variety tests of wheat showing earliness of Marquis. (Dr. C. E. Saunders, Experimental Farms, Ottawa, Canada)

Head-row test at Ohio Station showing variation in erectness of heads. (Agronomy Department, Ohio Station)

Head-row test showing variation in yield of straw and grain

Harvesting wheat plots at Cornell University. (Plant Breeding Department) ........

Spikelet of oats

89 90 91 93 101 102

117 120

130 134

135 136

141 146

LIST OF ILLUSTRATIONS xvii

51-52. Side and branched panicle of oats. (Plant Breeding

Department, Cornell University) . 53 Broad-casting oats. (Successful Farming)

54. Seeding oats with a drill

55. Testing varieties of cereals. (Dr. C. E. Saunders, Dominion

Experimental Farms, Ottawa)

56. Variation in stiffness of straw

57. Treating seed oats for smut. (Extension Department, Ohio

State University) .

58. Covered and loose smut of oats

59. Spikelets of barley

60. Two-rowed barley

61. Six-rowed barley .

62. A field of Manchurian barley at Indian Head, Canada. (Dr

C. E. Saunders)

63. A head of rye . • .

64. Plowing under rye. (Extension Department, Ohio State

148 157

159 160

161 162 165 166 167

65. Rye seeded in corn at last cultivation. (Successful Farming) 182

67. Harvesting rice in Arkansas. (Successful Farming) . . 188

68. Buckwheat in bloom . .190

69. Timothy in bloom. (Plant Breeding Department, Cornell

70. Cutting timothy hay. (International Harvester Company) 199

71. Plots of timothy at Cornell University. (Plant Breeding

Department) 200

72. Kentucky blue-grass. (Agronomy Department, Ohio Station) 202

73. Redtop. (Agronomy Department, Ohio Station) . . 207

74. Orchard grass in full bloom 210

75. Brome-grass. (Agronomy Department, Ohio Station) . 213

76. Meadow fescue. (Agronomy Department, Ohio Station) . 216

77. Common and Siberian millet 222

78. German millet 223

79. Broom-corn millet 224

80. Barnyard millet 225

81 Cutting sorghum. (Agronomy Department, Kansas Agricultural College) . . . • . . . .231

82. Heading kafir in Texas. (Professor A. G. McCall) . . 235

XVIU

LIST OF ILLUSTRATIONS

(Professor A. G. McCall)

FIGURE

83. Dwarf and standard broonicorn

84. Flowers of alfalfa ........

85-86. Diagram of typical legume flower and insect pollination

87. Applying lime to a field. {Coimtry Gentleman)

88. Nodules on roots of soy beans. (Extension Department,

Ohio State University) .

89. Red clover

90. Effects of lime on growth of red clover

91. Cutting clover hay ....

92. Using the tedder on a heavy hay crop

93. Rolling down clover. (Agronomy Department, Ohio Station)

94. Trailing stem of white clover. (Agronomy Department,

Ohio Station) .......

95. Alsike clover. (Agronomy Department, Ohio Station)

96. Using the side-delivery rake. (Agronomy Department

Ohio Station) .....

97. Curing clover hay in the cock

98. A crimson clover plant. {Country Gentleman)

99. An alfalfa plant. (Ohio Station)

100. Arrangement of leaflets in alfalfa and clover

101. Alfalfa roots. (Professor A. G. McCall) .

102. Stacking alfalfa in New Mexico. (Professor A. G. McCall)

103. Canvas covers on alfalfa cocks. (Agronomy Department,

Ohio Station) .......

104. Farmers examining alfalfa test plots at the Ohio Station

105. Vetch plant showing flowers, leaves, and tendrils

106. A sample of hairy vetch. {Country Gentleman)

107. A field of vetch in full bloom. {Successful Farming)

108. A sweet clover plant. (Extension Department, Ohio State

University) . . . ' .

109. Effects of lime on the growth of sweet clover

110. Sweet clover growing by the roadside. (Extension Depart

ment, Ohio State University) ....

111. A soy bean plant .......

112. A field of soy beans

113. Soy beans growing with corn. (Extension Department

Ohio State University) ......

114. Pods of cowpeas and soy beans .....

115. Cowpeas and corn. ( Country Gentleman)

PAGE

236 241 242 247

250 255 257

261 262 265

267 269

270 271 273

278 279 280 289

291 293 295 296 297

298 299

300 306 307

311 313 314

LIST OF ILLUSTRATIONS xix

116. A field of cowpeas. {Successful Farming) . . . 316

117. Canada field peas . 317

118. Peanuts 321

119. A sugar beet 325

120. Foreigners working in a beet field. (C. S. Wheeler) . . 328

121. Pasturing hogs on rape ....... 334

122. A cotton plant. (Alabama Station) 337

123. Production of cotton 345

124. Seed pods of flax 352

125. A bundle of flax and fiber. (Farmers' Bulletin 274) . . 353

126. Harvesting potatoes. (H. C. Ramsower) .... 364

127. A potato digger. (H. C. Ramsower) ..... 365

128. Hauling hay to market. (Extension Department, Ohio

129. Examining seeds for purity ...... 374

130. Testing grass and legume seeds ...... 375

131. A typical country elevator. (Grain Standardization Depart-

ment, United States Department of Agriculture) . . 382

132. A terminal elevator in Chicago 385

133. Inspecthig grain at Chicago ...... 388

134. A seaboard elevator. (Dr. C. E. Leighty) . . . .393

135. Unloading grain at a Danish port. (Dr. C. E. Leighty) . 394

FIELD CROP PRODUCTIOI^

Chapter I

All the plants that grow on the earth are called, collectively, the plant kingdom. The plant kingdom is made up of innumerable forms of vegetation, ranging in size from the tiny one-celled plant, so small that it cannot be seen with the unaided eye, to the giant trees of the forest. Between these two extremes are to be found myriads of intermediate forms, the algae that grow in ponds and streams, the mosses and lichens that grow on the trees and rocks, the ferns of the woods, the grasses and grains of the fields, the wonderful shrubs and plants with which we beautify our yards and gardens, and numerous other similar and related forms. Plants differ not only in their size, structure and habitat, but also in the kinds of food that they are able to use and in their usefulness to man. Some forms of vegetation are able to secure their food from the inanimate world in the form of chemical elements or compounds in the soil and in the atmosphere, and by certain life processes are able to convert them into forms useful in building up their own structures. Other forms are not able to do this, but must derive a part of their food from compounds that have already been incorporated in the bodies of other plants or animals. To the former class belong most of our cultivated plants, while in the latter class are to be found many of the plants that injure and produce disease in the cultivated forms. To this group belong the rusts and smuts that attack the grains, the blights and wilts that lay low the vegetables, and many other injurious, as well as some useful forms.

In their usefulness to man, plants vary greatly. They are of service to him principally in furnishing food, clothing, and shelter. They are also a factor in many industries, the products of which supply in some form or other the needs of man. Every industry, in fact, no matter how far removed from the growing of plants it may seem to be, is either directly or indirectly dependent upon it. The fundamental basis of any industry is to be found in the food supply of the people who engage in it, and of the people who consume the commodities produced. Men derive their supply of food principally from two sources, plants and animals. The animals, however, are either directly or indirectly dependent upon plants, so that, in the last analysis, the food supply of the nations of the world and consequently the existence of all the industries of the world are dependent upon the production of plants. Not all plants, however, are useful to man, many of the most troublesome diseases that attack the crops being plant growths.

1. Classification of plants. — Because the plant kingdom is made up of these multitudes of widely differing forms, it has been necessary for botanists, for purposes of study, to classify them into various groups. This branch of the study is called systematic botany, and has occupied the attention of botanists for many years. The classification has to do with the arranging of plants into groups, based upon their similarity of parts, — their evident relationship. While it is not necessary for the general

INTBODUCTOTtY VIEW 3

student of field crops to go exhaustively into the subject of systematic botany, a knowledge of its principles is necessary to a satisfactory understanding of field crops and of the terms employed in any discussion of them.

2. Species. — The grouping can best be understood perhaps if we start with the individual.^ If a seed of Kentucky blue-grass is planted, it will with favorable conditions for growth develop into a plant, which in time will produce seeds for its own perpetuation. If these seeds in turn are planted, they will give rise to other plants, which in time will produce seeds, and so on. Within a few years a large number of plants will result, the progeny of a single blue-grass seed. A careful examination of these plants will show that, while they are very much alike, slight variations occur in size, form and color of their various parts. While these variations may occur, the plants on the whole resemble each other very closely, having descended from a common ancestor. These plants and all others, w^ierever they may be found, resembling them so closely that they might well have come from the individual plant of which we spoke, are placed in a group called a species. A species, therefore, is made up of individuals so near alike that they may be regarded as having come from a common ancestor.

3. Variety. — As has been noted, slight variations occur among the individual members of a species. Sometimes variation in form, size or structure of a plant or its parts is such as to make it more useful to man than the other members of the species. Frequently man selects plants possessing some superior quality and develops from them, by using their seeds for perpetuation, a group of plants

1 Method of presenting classification of plants adapted from Percival's Agricultural Botany.

that varies slightly in some one or more characteristics from the other individuals in the species. Such a group of plants is called a variety. A variety, therefore, is a group of individuals within a species that possesses some variation from the species as a whole. As yet no varieties have been developed from Kentucky blue-grass, but examples of varieties in abundance may be had from the grain crops, such as corn and wheat. Thus we find many varieties of corn, such as Reid Yellow Dent, Boone County White, Calico, and many others. These varieties have some character or characters that distinguish them from corn in general. The color of the grain, the size of the ear and plants, the length of season required for growth, and similar variations are distinguishing variety characteristics.^ Varieties, however, are not so different from the other individuals of the species as to form a separate and distinct species by themselves. Thus Reid Yellow Dent and Boone County White, and all other varieties of corn, are members of the corn species Zea Mays.

4. Genus. — If one examines closely all kinds of grasses, it will be found that certain kinds bear a close resemblance to Kentucky blue-grass, in the general appearance, manner of growth, structure of parts, the arrangement of flowers, and the like.^ Thus such species as Canada blue-grass. Rough-stalk meadow-grass, and

iln presenting the scheme of classification of plants, the author has used such general terms as " manner of growth," and " general appearance" in referring to varietal and generic characteristics, viewing the subject from the agronomist's point of view, as the discussion for elementary students of the plants with which he deals does not necessitate going into the intricate distinctions employed by the botanist. The term " variety " is used in the agronomic sense, not as a sub-species as the botanists use it.

Wood's meadow-grass so closelj^ resemble Kentucky blue-grass as to establish with it a close relationship. Species which are thus closely related are placed in a group called a genus. A genus, therefore, is a group of closely related species.

5. Naming of plants. — For convenience in describing and identifying the various species that comprise a genus, and to distinguish the various genera, it has been necessar}^ to name plants in such a way as to indicate the species and genus to which they belong. The botanical or scientific name of a plant is composed of two Latin words, the first of which is the name of the genus and the second that of the species. Thus Kentucky blue-grass is known as Poa 'pratensis, Canada blue-grass as Poa co7npressa, Rough-stalked meadow-grass as Poa trivialis, and Wood's meadow-grass as Poa nemoralis. Varieties of farm crops are not given Latin names, but frequently are named for the man who is responsible for their development, as Reid Yellow Dent corn, or sometimes for the section of the country in which they were developed, as Boone County White, or by some other distinguishing name, such as Pride of the North, Rust-proof, Medium Green, and the like.

6. The family. — On observing the pasture and meadow grasses, one will almost immediately note their similarity and general appearance, manner of growth, shape of leaves, character of stems, and other characters. It may be seen, however, that this resemblance is not close enough to group them all in the same genus, but that the various genera are similar and may be classed together in a larger group, which is called the family. Thus the meadow and pasture grasses together with other grasses may all be included in a large group or family, called the Gramineae or grass family. The family group may include genera of considerable variation in size or other characters ; thus oats, wheat, barley, and even corn, each of which belongs to a different genus, are all members of the grass family. But the variation between oats and the meadow grasses like timothy is not so great as would appear without examination of the plants themselves. Examination will reveal the similarity in the character of growth, shape, and structure of the leaves, stem, and flowers. The nearness of their relationship will become more evident if one of them is compared with a species of another family, such as one of the clovers. Immediately a great dissimilarity between these will be noticed in the leaves, stem, roots, and flowers.

7. Orders, classes, and divisions. — As genera and families have been formed, so are the closely related families grouped into orders. Orders with similar characters are grouped into classes, and similar classes form divisions. The division represents the largest group of the plant kingdom.

8. Divisions. — The plant kingdom has been divided into four great divisions, namely, Thallophytes, Bryophytes, Pteridophytes, and Spermatophytes. The Thallophytes and Bryophytes comprise the lower forms of plants ; the algae, fungi, and bacteria belonging in the former group, and the liverworts and mosses in the latter. The plants of these two divisions have neither true stems nor leaves, nor do they produce flowers and seeds. The Pteridophytes include the ferns and related plants. The plants of this division have stems and leaves, but do not produce true flowers or seeds. These three great divisions of the plant kingdom, Thallophytes, Bryophytes, and Pteridophytes, are often grouped together into the " flowerless plants." The one remaining group, namely, the Spermatophytes, includes all of the seed-producing plants. To this group belong almost all of the cultivated plants, and it is by far the most important division in its relation to mankind. The Thallophytes, however, are of considerable importance to man in that within its membership are to be found the bacteria, both useful and harmful, and also the numerous plant diseases. The farmer, therefore, is economically interested chiefly in only two of the great divisions of the vegetable kingdom, the Thallophytes and the Spermatophytes.

The two classes of Spermatophytes are the Gymnosperms and the Angiosperms. The Gymnosperms include those plants the seeds of which are naked or not inclosed, and are formed on the outside of a modified leaf. A large number of the Gymnosperms are coniferous or conebearing trees, such as the pine, cedars, yews, and similar plants. The Angiosperms include those plants whose seeds are inclosed in pod- or sac-like structures. To this group belong almost all of the cultivated plants. The Angiosperms may be divided into two sub-classes, namely, the Dicotyledons and the Monocotyledons. The dicotyledonous plants may be distinguished by the presence of two cotyledons or seed leaves, while the monocotyledons have but one. Both dicotyledonous and monocotyledonous plants are to be found in our cultivated forms. The Leguminosse, to which belong the clovers, peas, and beans, is an example of the former, while the Graminese, or grass family, to which belong the grasses and grains, is an example of the latter.

9. Length of life. — Based upon their length of life, plants may be divided into annuals, biennials, and perennials. An annual is one that lives only during one growing season. A biennial is one that requires two growing seasons to complete the life cycle, no seeds being produced during the first season, but only leaves, stems, and roots. The seed is produced the second season. Perennials are plants that live for more than two years. Some perennials, such as alsike clover, live but a short time, three or four years or so, while other perennials, such as alfalfa and blue-grass, live for many years. Some annuals utilize parts of two growing seasons, instead of making all their growth in one season. An example is winter wheat, which makes a partial growth during the fall and completes its growth the next year. Such plants are called winter annuals.