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Bulletin 273 
 
 January, 1926 
 
 (Euuurrttrut Agricultural iExurrtmrut ^tattuu 
 £faw ijatiftt, Qlomiprttrut 
 
 Crossed Corn 
 
s 
 
 Bulletin 273 January, 1926 tToJO 
 
 Qlontiprttntt Agrtrultural {Expmmrttt Station 
 
 N* ro lHaupn, (EDuttrrttrut 
 
 CROSSED CORN 
 
 D. F. JONES 
 P. C. MANGELSDORF 
 
 The Bulletins of this Station are mailed free to citizens of Connecticut 
 who apply for them, and to other applicants as far as the editions permit. 
 
CONNECTICUT AGRICULTURAL EXPERIMENT STATION 
 
 OFFICERS AND STAFF 
 January, 1926 
 
 BOARD OF CONTROL. 
 His Excellency, John H. Trumbull, cx-officio, President. 
 
 Charles R. Treat, Vice-President Orange 
 
 George A. Hopson, Secretary Mount Carmel 
 
 Wm. L. Slate, Jr., Director and Treasurer New Haven 
 
 Joseph W. Alsop Avon 
 
 Elijah Rogers Southington 
 
 Edward C. Schneider Middletown 
 
 Francis F. Lincoln Cheshire 
 
 Administration. 
 
 Chemistry. 
 Analytical Laboratory. 
 
 Biochemical 
 Laboratory. 
 
 Botany. 
 
 Entomology. 
 
 Forestry. 
 
 Plant Breeding. 
 Soil Research. 
 
 Tobacco Sub-station 
 at Windsor. 
 
 STAFF. 
 E. H. Jenkins, Director Emeritus. 
 
 Wm. L. Slate, Jr., B.Sc, Director and Treasurer. 
 Miss L. M. Brautlecht, Bookkeeper and Librarian. 
 Miss J. V. Berger, Stenographer and Bookkeeper. 
 Miss Mary E. Bradley, Secretary. 
 G. E. Graham, In charge of Buildings and Grounds. 
 
 E. M. Bailey, Ph.D., Chemist in Charge. 
 
 K. h. Andrew, M.A. 
 
 C. E. Shepard 
 
 Owen L. Nolan V Assistant Chemists. 
 
 Harry J. Fisher, A.B. 
 
 W. T. Mathis J 
 
 Frank C. Sheldon, Laboratory Assistant. 
 
 V. L. Churchill, Sampling Agent. 
 
 Miss Mabel Bacon, Stenographer. 
 
 T. B. Osborne, Ph.D., Chemist in Charge. 
 
 G. P. Clinton, Sc.D., Botanist in Charge. 
 
 E. M. Stoddard, B.S., Pomologist. 
 
 Miss Florence A. McCormick, Ph.D., Pathologist. 
 
 Willis R. Hunt, Ph.D., Assistant in Botany. 
 
 A. D. McDonnell, General Assistant. 
 Mrs. W. W. Kelsey, Secretary. 
 
 W. E. Britton, Ph.D., Entomologist in Charge; State Ento- 
 mologist. 
 
 B. H. Walden, B.Agr. ) 
 
 M. P. Zappe, B.S. V Assistant Entomologists. 
 
 Philip Carman, Ptt.D. ' 
 
 Roger B. Friend, B.S., Graduate Assistant. 
 
 John T. Ashworth, Deputy in Charge of Gipsy Moth Work. 
 
 R. C. Botsford, Deputy in Charge of Mosquito Elimination. 
 
 Miss Gladys M. Finley, Stenographer. 
 
 Walter O. Filley, Forester in Charge. 
 H. W. Hicock, M.F., Assistant Forester. 
 Miss Pauline A. Merchant, Stenographer. 
 
 Donald F. Jones, S.D., Geneticist in Charge. 
 P. C. Mangelsdorf, S.D., Assistant Geneticist. 
 
 M. F. Morgan, M.S., Investigator. 
 
 George D. Scarseth, B.S., Graduate Assistant. 
 
 Paul J. Anderson, Ph.D., Pathologist in Charge. 
 N. T. Nelson, Ph.D., Assistant Physiologist. 
 
 THE TUTTLE, MOREHOUSE & TAYLOR COMPANY 
 
CROSSED CORN 
 
 D. F. Jones and P. C. Mangelsdorf. 
 
 Vigorous, sturdy plants, a good sound ear on every stalk, no 
 weak and spindling plants, few nubbins or moldy ears. These 
 are some of the outstanding characteristics of crossed corn. It is 
 all these desirable features combined that enable this new kind of 
 corn to outyield the old standard varieties, year after year, and 
 under all sorts of conditions. 
 
 Crossing two distinct types of animals or of plants almost 
 always causes an increase in vigor. This has long been known 
 and used in the production of mules, sterile hybrids of the horse 
 and the ass. Swine breeders often utilize the beneficial effects 
 of hybrid vigor by crossing different breeds of pigs, feeding for 
 market the hybrid offspring but not breeding from them. 
 
 The same principle can be used in increasing the yield of corn 
 and the Connecticut Agricultural Experiment Station has been 
 working for many years to find the best methods of utilizing hybrid 
 vigor and to produce strains of corn for crossing that give high 
 yields adapted to the cultural and market requirements of this 
 region. 
 
 Several promising types of crossed corn have now been pro- 
 duced, of which stock seed is available for seed growing. Other 
 types are now being developed to meet different requirements 
 and these will soon be available for distribution. 
 
 The uniform production from every plant, though the most 
 important feature, is only one of the desirable characteristics of 
 crossed corn. The ears are more even in size and shape, there 
 are fewer nubbins, poorly developed ears and moldy corn. Many 
 combinations show appreciably less smut and root rot infection. 
 The stalks themselves are sturdy and strong and stand up when 
 other plants are laid low by wind and rain. In time of tasseling 
 and silking the crossed plants are far more even than ordinary 
 varieties and in ripening there is the same remarkable uniformity. 
 
 In crossed sweet corn this uniformity in time of ripening is a 
 very valuable feature for the market gardener or canner. It 
 enables the grower to harvest his crop at one time and have 
 practically all of the ears ready to be picked. This results in a 
 better quality of canned or table corn, because fewer immature 
 and over-ripe ears are included. 
 
 The uniform size of the ears is also particularly desirable in 
 the case of sweet corn. It makes for a more attractive product 
 and is a feature that appeals especially to the restaurant trade. 
 
154 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 SEED SELECTION. 
 
 The uniformity of crossed corn, its evenness in ripening, its 
 increased productiveness, the greater freedom from disease, cannot 
 be obtained by any of the usual methods of seed selection in 
 naturally-pollinated fields of corn. 
 
 Fig. 1. — Vigorous, sturdy plants with a good ear 
 characteristic of crossed corn. 
 
 >n every stalk are 
 
 One may go through a field or crib of corn, picking out the 
 largest and finest ears, discarding all poorly filled and moldy ears 
 and keeping only the one best ear out of every thousand, and yet 
 these choice specimens do not reproduce their excellence ; they do 
 not "breed true." No matter how fine in appearance are the 
 ears which are planted, they always give many weak plants and 
 non-producers. 
 
 The failure of the finest ears to reproduce themselves has 
 several causes. It is due, in part, to the fact that many of the best 
 
CROSSED CORN 
 
 '55 
 
 ears are good, not because of their heredity but because of the 
 especially favorable situation in which they grew. It is solely 
 
 Fig. 2. — In size and shape of ear and in time of ripening there is a 
 remarkable uniformity. 
 
 their environment that has made them better than the average 
 and the effects of environment, we now know, can not be passed 
 on to later srenerations. 
 
»56 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 273 
 
 The main reason, however, that the selected ears do not breed 
 true lies in the fact that the pollen which produced their seeds 
 came from all sorts of plants. Every silk must receive pollen 
 in order for a seed to develop. The pollen is shed by the tassels 
 and good, poor and indifferent plants alike send their pollen into 
 the air where it is mixed by the wind and carried to all parts of 
 the corn field. The choicest ear in the entire field has received 
 part of its pollen from some of the poorest neighbors. 
 
 Fig. 3. — The plants grown from the small ears were just as large and 
 the yield of shelled grain was the same as from the large seed ears. 
 
 This constant inter-crossing and hereditary mixing going on in 
 every corn field has brought about a condition whereby every plant 
 is a hybrid of greater or less degree of complexity and the off- 
 spring of hybrids are usually diverse and seldom like their parents. 
 Moreover, corn has been naturally crossed in this way for count- 
 less years and is dependent upon hybrid vigor to produce its 
 largest yield. 
 
 In spite of the natural crossing which is constantly going on, 
 it is possible by ordinary field selection, patiently practiced, year 
 after year, to bring about an improvement in certain respects. By 
 saving for seed only the ears from the earliest ripening plants 
 one may in time develop a variety that will mature somewhat 
 
CROSSED CORN 157 
 
 earlier. By choosing plants with many ears, the average number 
 of ears per stalk can be gradually increased. Noticeable changes 
 can be made in the number of rows of grain on the ear, the size 
 and shape of the ear or the type of kernel. 
 
 Selection of this kind is usually made with some definite aim 
 of adapting the variety more perfectly to the purpose for which 
 it is grown. Such alterations are seldom accompanied by any 
 increase of yield and often, particularly where extreme earliness 
 is sought, productiveness is lowered. 
 
 Tests carried out at many places have shown that the prize 
 winning ears at the corn shows often yield no more than unselected 
 ears that are much less desirable in appearance. This fact is 
 brought out in the accompanying illustration. Plants grown from 
 the nubbins at the right were just as strong as those produced 
 by the good ears shown on the left. The ears were fully as 
 large and the yield of shelled corn was exactly the same. 
 
 In this case the difference in appearance of the two lots of 
 seed ears was not due to heredity but merely to the conditions in 
 the field in which they grew, the one in a good situation, the other 
 in a poor one. 
 
 THE EAR-TO-ROW METHOD OF SELECTION. 
 
 When the seed from a number of ears of corn are planted sep- 
 arately, each in a row by itself, some lots grow better and yield 
 considerably more than others. It was formerly thought that by 
 selecting seed from the high producing rows or planting the remain- 
 ing seed from the best yielding mother ears, and continuing this 
 process from year to year, an increase in yield could be obtained. 
 A marked increase in yield is sometimes obtained the first year or 
 two but extensive tests have shown that the differences are not 
 permanent and that in later generations the yield from the orig- 
 inally high producers is no more than that obtained from the 
 unselected seed. 
 
 The failure of the high producing ears to maintain their 
 increased yields is probably due to their hybrid composition. They 
 split up and lose vigor in later generations. Selection towards a 
 single type also brings about a certain amount of inbreeding which 
 always weakens the plants. 
 
 HYBRID VIGOR. 
 
 Crossing somewhat different but related forms of plants or 
 animals results in greater growth, the offspring often being better 
 than either parent. Blue-gray cattle have long been used for 
 beef in Scotland. They are the result of crossing a white Short- 
 horn bull and black Gallowav or Angus cows. The large growth. 
 
'58 
 
 CONNECTICUT EXPERIMENT STATION- 
 
 BULLETIN 273 
 
 early maturity and fine beef quality has given this breed cross 
 an enviable reputation whereever beef cattle are raised. 
 
 The Carolina poplar is a thrifty, fast-growing - tree that succeeds 
 well in nearly all parts of the country. It is considered to be a 
 
 Fig. 4. — Two dwarf types of corn give an astonishing result when 
 crossed. 
 
 natural hybrid between the Cottonwood of our western plains and 
 the European Black poplar. A valuable feature of this tree is the 
 ease with which it can be grown from cuttings. Its vigorous 
 nature is thus easily maintained while at the same time the trees 
 are multiplied in numbers. 
 
 Hybrid vigor is usually responsible for part of the value of 
 most vegefatively propagated plants. As long as they are not 
 
CROSSED CORN 
 
 *59 
 
 reproduced from seeds the stimulus to increased growth is main- 
 tained undiminished. In naturally cross-pollinated plants it is 
 necessary to keep up a constant intercrossing in order to maintain 
 full vigor. 
 
 The corn plant is so constructed with its tassel, the pollen- 
 bearing structure, at the top of the stalk, that it can be easily 
 detasseled before pollen is shed, thereby entirely preventing self- 
 fertilization. Fifty years ago a method was outlined whereby 
 two varieties of corn could be crossed by planting them in alternat- 
 
 Fig. 5. — The corn plant is so constructed that it can easily be crossed 
 by planting in alternating rows and detasseling all of the plants of 
 one kind before pollen is shed. 
 
 ing rows and pulling out all the tassels of one variety before pollen 
 is shed. All of the seeds borne on such emasculated plants must 
 result from cross-pollination of one variety with another. 
 
 Numerous tests have shown that an increased yield often results 
 when certain varieties of different type, such as flint and dent, are 
 crossed. Some varieties of corn from China when crossed with 
 native varieties have given considerably larger yields than either 
 parent. Crossing an early variety with a late variety sometimes 
 gives a cross-bred progeny that yields as much as the later parent 
 and is appreciably earlier. Varieties of similar type when com- 
 bined have not given much better results than either parent. 
 
 The increased yields which are obtained come only the first 
 year after crossing. To get the benefit of hybrid vigor in plants 
 reproduced by seeds it is necessary to make the cross each year 
 and plant only the crossed seed. Any improvement in yield or 
 
i6o 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 273 
 
 in other respects must be great enough to repay the extra cost of 
 producing seed in this way. Variety crosses, while better than 
 their parental stocks in some cases, have not, apparently, offered 
 sufficient improvement to induce corn growers to make a practical 
 application of this method. 
 
 Fig. 6. — The result of seven generations of inbreeding. 
 
 INBREEDING BEFORE CROSSING. 
 
 A larger increase in yield together with a much greater uni- 
 formity and fixity of type is obtained by first inbreeding corn 
 by artificial hand pollination for several years and then crossing 
 two different inbred strains. This is shown in the accompanying 
 illustration. A variety of Learning which yielded 96 bushels per 
 acre was inbred, that is, the silks were artificially pollinated with 
 pollen from the same plants. After five years of inbreeding two 
 strains, one of which had been reduced in yield to 32 bushels per 
 acre, the other to 20 bushels, were crossed. The first genera- 
 tion cross of these two low yielding, inbred strains produced 115 
 bushels, an increase of twenty per cent over the original variety, 
 under the same conditions. Not only did this hybrid exceed the 
 original variety by twenty per cent in yield but the corn was of 
 better quality. The ears were all closely alike in size and shape 
 and all matured at practically the same time. Every stalk bore 
 a good ear and there were fewer moldy ears, nubbins and less 
 soft corn. 
 
CROSSED CORN l6l 
 
 Here is a marked improvement secured by crossing. Unfor- 
 tunately this particular cross and many other combinations made 
 in the early years of these experiments were not well adapted to 
 Connecticut conditions. The plants ripened too late to make a 
 satisfactory corn for husking and the stalks were not large enough 
 to make a good silage variety. Also the low yields and poor 
 quality of the inbred strains made it practically impossible to 
 produce crossed seed in quantity and at a price that would justify 
 its use. 
 
 At the present time every effort is being made at this station and 
 throughout the corn-growing states to produce inbred strains that 
 
 
 Fig. 7. — The two inbred strains were derived from the variety on the left 
 and gave the result on the right when crossed — 115 bushels per acre. 
 
 will give hybrid combinations well adapted to the local needs and 
 which will be themselves sufficiently vigorous and productive to 
 make the growing of crossed seed commercially profitable. Other 
 methods of utilizing inbred strains of corn are being developed. 
 
 Crossed corn seed has now been grown in Connecticut five 
 years and tested long enough to show its possibilities. Two 
 crosses of inbred strains outyielded all varieties in the Iowa corn 
 yield contest in 1924 in the south central section. One of the 
 inbred strains used in one of these crosses was developed at this 
 station. 
 
 A combination of four inbred strains known as Double Crossed 
 Burr-Learning has been tested for five years in comparison with 
 the highest yielding varieties grown in this part of the country 
 with the following results : 
 
 r-Bushels of shelled corn per acre—-, 
 Highest Yielding Varieties 
 
 D. C. Burr-Leaming . 
 Beardsley's Learning . 
 
 Luce's Favorite 
 
 Webber's Dent 
 
 Northern White Dent 
 Century Dent 
 
 1018 
 
 i<pto 
 
 1920 
 
 1921 
 
 1922 
 
 Average 
 
 116 
 
 88 
 
 55 
 
 95 
 
 63 
 
 83 
 
 Q6 
 
 54 
 
 5i 
 
 85 
 
 48 
 
 67 
 
 
 79 
 
 38 
 
 81 
 
 50 
 
 62 
 
 81 
 
 62 
 
 57 
 
 73 
 
 49 
 
 64 
 
 84 
 
 75 
 
 32 
 
 87 
 
 
 69 
 
 68 
 
 5i 
 
 55 
 
 77 
 
 67 
 
 64 
 
162 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 Fig. 8. — The uniform production of a good ear from every stalk 
 gives high yields. 
 
 Fig. 9. — Double Crossed Burr-Learning grown at Durham, Connecticut. 
 
 Double Crossed Burr-Learning has been grown in many other 
 parts of the state and in various places in the corn-growing districts 
 
CROSSED CORN 
 
 16 
 
 south and west. In most cases it has out-yielded all other varie- 
 ties, the stalks have stood erect in the fields until harvest and the 
 leaves have remained green until the ears are well glazed. 
 
 A cross of two inbred strains of sweet corn grown for canning 
 has yielded six tons of ears per acre in comparison with three and 
 one-half tons from Evergreen corn. 
 
 Fig. io. — Weak golden colored plants when crossed with dwarfs 
 give all tall and vigorous progeny. 
 
 WHAT INBREEDING DOES. 
 
 Many abnormal or freak types of corn are known, such as dwarf 
 plants, golden plants, which lack the normal green coloring" matter 
 necessary to manufacture food, liguleless plants, with upright 
 instead of spreading leaves, and other characters which seriously 
 weaken the plants and reduce their ability to produce grain. These 
 abnormalities are inherited and pure breeding strains can be 
 maintained from vear to vear. 
 
164 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 273 
 
 When one of these unusual types is crossed with a normal plant 
 only normal plants are produced in the first generation but the 
 abnormality reappears in the second generation and may be recov- 
 ered and made to breed true again, showing that these weakening 
 characters are hereditary. 
 
 When, for example, a golden-leaved, liguleless plant is crossed 
 with a dwarf form there result in the first following generation 
 only vigorous, tall growing, dark green plants with spreading 
 
 Fig. 11. — The second generation from the cross of golden, liguleless and 
 dwarf. Eight different combinations of these characters are obtained. 
 
 leaves, all normal in every respect, uniformly vigorous and produc- 
 tive as shown in Figure 10. 
 
 Self-fertilizing these plants or allowing them to inter-pollinate 
 gives an astonishing medley of plants in the next generation. 
 There will be dwarf plants, golden plants and liguleless-leaved 
 plants and some with two and even three of these abnormal char- 
 acters combined in one individual. There will be some plants that 
 are normal in all characters but very few will be as vigorous or 
 productive as the first crossed plants. 
 
 The difference between the first and the second generation in 
 respect to uniformity, size and productiveness is a very striking 
 illustration of the bad effects of inbreeding. This is an extreme 
 example but the same principle holds with naturally cross-fertilized 
 
CROSSED CORN 
 
 165 
 
 plants and with bisexual animals. In most cultivated plants such 
 clear-cut abnormalities are not involved. 
 
 When any ordinary variety of corn is self-pollinated there is a 
 noticeable reduction in size and yield and this usually continues 
 for five or six generations. From this point on there is seldom 
 
 Fig. 12.— The descendants of a single plant after four generations 
 of self-fertilization. 
 
 Fig. 13. — The plants within an inbred line are all closely alike but 
 differ from every other line. 
 
 any further reduction. The plants in these generations, in any 
 one strain, come to be all closely alike and remain fixed in their 
 type from then on as long as they are not outcrossed to plants 
 of different ancestry. 
 
 Every inbred strain descending from individual plants at the 
 start is different to a greater or less extent from every other 
 strain even though they all come from the same variety. Some 
 are tall, others short. In color of leaves, silks and glumes, great 
 
1 66 
 
 CONNECTICUT EXPERIMENT STATION BULLETIN 2/3 
 
 diversity is found and in the size and shape of the ears, time of 
 ripening, ability to stand erect and in number and size of tillers 
 there is marked dissimilarity. Productiveness ranges all the way 
 from little or nothing up to a fair yield for inbred plants but no 
 
 Fig. 14. — Crossing inbred strains immediately restores vigor and 
 productiveness. 
 
CROSSED CORN 
 
 167 
 
 inbred strains have been obtained which are as productive as the 
 original variety and usually the yields are reduced to less than 
 half and the size of the seed and quality of the grain are propor- 
 tionately lowered. 
 
 Since all of the plants within an inbred line come to be closely 
 alike it makes no difference from that point on whether the plants 
 are self -fertilized or are allowed to inter-cross among themselves. 
 Their size and productiveness remain the same as long as pollen 
 from all other kinds of corn is kept away from them. 
 
 When an inbred strain is crossed with another strain from the 
 
 Fig. 15. — When rightly grown, crossed corn has no barren stalks or poor 
 producers. 
 
 same or different variety there is a very great increase in size and 
 yield in the next generation as we have already seen. In size the 
 crossed plants are as large or larger than the original variety and 
 in yield of grain they are often superior. 
 
 This is due apparently to the fact that the good qualities of 
 both parents are expressed in the offspring while the weak qualities 
 are covered over for the time being. Thus in the cross of golden, 
 liguleless with dwarf the offspring are normal in every respect. 
 The yellow foliage color, the upright posture of the leaves and the 
 dwarfness of the stalk are all suppressed in this generation. What 
 one parent lacks is supplied by the other, and conversely. Hybrid 
 vigor seems to be a wise provision on the part of nature to enable 
 the offspring to make the best of bad ancestry. 
 
 While most of the inbred strains do not have freak characters 
 they are all lacking something which makes for full size and pro- 
 ductiveness. Crossing any two strains usually brings back suffi- 
 
1 68 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 cient vigor to make the plants as productive as the original variety 
 while certain combinations are very much superior. 
 
 The greater production of crosses of inbred strains is not due 
 so much to the large size of the ears as to the fact that every 
 plant, if given an equal opportunity to grow, produces a good 
 ear. Some of the ears of the original variety may be larger and 
 finer than any produced by the hybrid but for every plant of this 
 kind there are many stalks that have only nubbins and even some 
 that are entirely barren. 
 
 The uniform production of an average good ear from every 
 plant is largely responsible for the high yield of crossed corn. 
 The even size and maturity also have distinct value in sweet corn 
 for market gardening and canning. 
 
 HYBRID VIGOR NOT PERMANENT. 
 
 These desirable results are obtained only the first year after 
 crossing. The second generation grown from the fine looking 
 hybrid ears fall off in yield about 20 per cent as a general rule. 
 While the amount of reduction may differ greatly this result 
 always follows when hybrid corn, no matter how vigorous it may 
 be, is used again for seed. This holds true whether the crossed 
 plants are self-fertilized artificially or are allowed to inter- 
 pollinate naturally. 
 
 A cross of two inbred strains grown six years averaged 101 
 bushels per acre. The second generation of this cross from self- 
 pollinated first generation plants grown the same years and com- 
 pared under equal conditions gave an average of 69 bushels, a 
 decrease of more than 30 per cent. 
 
 The Nebraska Station compared the first and second generations 
 of eight hybrid combinations during two seasons and obtained 
 an average of 52.2 and 27.8 bushels per acre respectively for the 
 two successive generations. The original variety from which the 
 inbred strains were derived gave 41.7 bushels in the same period. 
 In this case the reduction in yield from the first to the second 
 generation is nearly 50 per cent. The second generation was 
 grown from seed produced by inter-pollinating the first generation 
 plants. 
 
 Not only is there this decided decrease in yield but uniformity 
 is also lost. In size and shape of ear, height of plant and in time 
 of ripening the second generation is even more variable than 
 ordinary varieties. 
 
 If the second generation is again inbred the whole story of the 
 production of inbred strains is repeated. There is a continued 
 decrease in size and yield, as in the first period of inbreeding, and 
 the reduction continues for about the same number of generations. 
 
CROSSED CORN 169 
 
 five to seven on the average, until uniformity and constancy are 
 again reached. The inbred plants are generally no more vigorous 
 than those of the previous inbreeding although they differ from 
 their parental strains and from each other in minor characteristics. 
 In other words hybrid vigor is a transitory effect and ordinarily 
 can not be fixed and made permanent except in plants propagated 
 vegetatively. Varieties of fruits, vegetables and flowers that are 
 reproduced by tubers, roots, grafts or other asexual methods of 
 propagation owe their value to a superior combination of heredi- 
 tary factors which produce the qualities desired and which also 
 give plants a large amount of hybrid vigor. This is shown by 
 their seedlings which are almost invariably weaker and poorer in 
 many respects. 
 
 Fig. 16. — The first generation cross of two inbred strains will not 
 continue to give as satisfactory results the next year. If inbred it 
 will decline in vigor as in the first period of inbreeding. 
 
 Unfortunately from the standpoint of utilizing hybrid vigor, 
 corn can not be reproduced in any way except by seeds. It can, 
 however, be easily crossed. For that reason it is feasible to pro- 
 duce crossed seed for planting each year and grow only the first 
 generation hybrid plants for production of sweet corn ears, grain 
 or silage. 
 
 The additional cost of crossed seed is more easily justified for 
 corn than for other crops because the cost of seed is a smaller 
 item in the outlay for producing a crop of corn than for any other 
 plant commonly grown. 
 
 SELECTION IN SELF-FERTILIZED LINES. 
 
 The character, productiveness and general value of any com- 
 bination of inbred strains, can not be accurately determined from 
 the inbred strains themselves. Many strains which are weak and 
 undesirable in their inbred condition give astonishing results when 
 
17° CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 crossed. It is necessary therefore to test out many combinations 
 to secure the ones that have outstanding value. 
 
 Not all crosses of inbred strains are superior to the original 
 variety and like every other good product crossed corn requires 
 extensive selection and much thorough testing in order to obtain 
 something of real merit. 
 
 To have a reasonable chance of securing a good combination, 
 many inbred strains must be obtained and then tested in many 
 combinations. This work for the present can best be done by the 
 State Experiment Stations and the Federal Department of Agri- 
 culture until the method is more generally used. The prospect 
 of obtaining a particularly fine combination and being able to 
 control the stock strains from which this cross is obtained holds 
 out an inducement to originate valuable inbred strains. Never 
 before in agricultural history has a seedsman been able to control 
 a valuable plant improvement. 
 
 He who invents a new machine or a new process of manufac- 
 turing can patent his product and reap a reward for his industry 
 and inventiveness. The originator of a new and improved plant 
 or animal ordinarily loses control of his product as soon as he sells 
 his first seeds or breeding stock. 
 
 With crossed corn the situation is entirely changed. The seed 
 that is sold is used to produce a superior crop of corn but this 
 in turn can not be used for further planting and the only way 
 the same result can be secured is to obtain seed from the original 
 producer each year. This is an advantage that will result bene- 
 ficially to both the seedsman and the one who plants the seeds. 
 This will stimulate the production of better kinds of corn as 
 nothing else has ever done. Larger crops of better corn will be 
 harvested on the same acreage and with the same labor. There- 
 fore the cost of producing a bushel of corn will be reduced. 
 
 At this Station the method of obtaining good inbred strains is 
 as follows. A variety is chosen which has been thoroughly tested 
 and is known to be well adapted to the purposes to which it is to be 
 put. A large number of the best ears of this variety are selected 
 and seed from each ear is planted in a separate row in the field. 
 About 20 to 30 plants are grown in each row. When the plants 
 are ready to silk out five of the best plants are self-pollinated 
 by hand. 
 
 This is a simple process with corn. A "three pound" paper sack 
 is placed over the ear shoot as soon as it appears and before any 
 silks are showing. The bag is slipped over the ear shoot without 
 being opened and is held in place with a wire paper clip. At the 
 same time, or a day or two later, an "eight pound" bag is put 
 over the tassel and securely fastened around the stalk at the base 
 of the tassel, also with a wire clip. 
 
 Two or three days later, depending upon the weather, when 
 
CROSSED CORN i 7 I 
 
 the silks are out about three inches beyond the tip of the ear, the 
 tassel is bent over and shaken into the tassel bag which has been 
 unfastened. This collects the fine yellow powder, the pollen, which 
 is dusted over the silks. The small bag is replaced quickly over 
 the ear and the larger tassel bag is put over this, thus guarding 
 against breaks in the bags which will let in pollen from outside. 
 The bags are left on until the ears are gathered in order to 
 mark them. 
 
 Pollination can only be done when the bags are dry. Wet 
 
 Fig. 17.- — Self-fertilizing corn by hand pollination. 
 
 weather or heavy dew which causes the pollen to clump together 
 renders it unfit for use. Only a very small quantity of good 
 pollen is needed and this should be applied as soon as possible 
 after the silks appear. 
 
 Care is taken to avoid touching the silks with the hands and 
 also nearby plants are pushed away so that their pollen will not 
 fall on the silks. Hand pollination in this way insures that the 
 ears are fertilized with pollen from the same plant. This is the 
 closest kind of inbreeding and will have very noticeable effects on 
 the resulting progeny. 
 
 An inbred strain starting from an ear, borne on one plant, is 
 called a self-fertilized line. From the five hand pollinated ears 
 made the first vear in each line, three of the most desirable are 
 
172 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 273 
 
 selected for planting- the next year. These three progenies are 
 grown in rows and two plants are self-pollinated by hand in each 
 row. ■ . 
 
 Fig. 18. — Two self-fertilized lines from the same variety which 
 differ remarkably in height. 
 
CROSSED CORN 
 
 173 
 
 Fig. 19. — Ability to stand erect has a basis in inheritance as these two 
 strains were derived from the same variety and grown for fifteen years 
 under the same conditions. 
 
 At harvest the best and second best of the three progenies are 
 noted in each line. Two ears from the best and one from the 
 next best are planted the following year and this system is fol- 
 
174 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 2/3 
 
 lowed for three or four generations. At that time many of the 
 lines are fairly well fixed in their type and are uniform. 
 
 There are great differences between the several lines. Some are 
 tall, others short and all degrees in between. Some have many 
 tillers, others have few or none. Differences in ability to stand 
 erect, in amount of smut damage, mold on the ears, and other 
 characters of greater or less importance are noted. 
 
 Some lines are so unproductive that it is difficult to secure any 
 seed from them. A number of promising strains are found that 
 make a fairly good ear on every plant, all of the plants stand up 
 during the season and have qualities that make them appear of 
 value although few of them are more than half as productive as 
 the variety started with. Nearly all of them are later in maturing 
 than the variety at the start on account of their weakened condi- 
 tion. When crossed the plants grow and mature much faster and 
 the value of the inbreeding process is at once apparent in the 
 crossed progenies. 
 
 To obtain the best results it is necessary to test all of the best 
 appearing inbred strains in combinations with each other. This 
 is most easily done by hand-pollination, putting the pollen of one 
 strain on the silks of the other and keeping a record of the 
 strains combined. 
 
 METHODS OF PRODUCING CROSSED SEED. 
 
 When a good combination of two inbred strains, called a single 
 cross, is once found it is a comparatively simple matter to produce 
 crossed seed in quantity by planting the two inbred strains in 
 alternate rows : . 
 
 A 
 
 A 
 
 B etc. 
 
 A = the pollen parent rows ; the tassels are left on and seed from 
 these plants is inbred and can be used for planting in a 
 crossing plot another year. 
 
 B = the seed parent rows with all the tassels pulled out ; seed 
 from these plants gives crossed corn. 
 
 All of the plants of one kind are detasseled before any pollen 
 is shed. This is done by pulling out or breaking off the tassel 
 as soon as it appears above the leaves at the top of the stalks. Pol- 
 len is scattered by the wind as soon as the anthers, the tiny sacks 
 suspended on short threads from the tassel branches, appear. 
 These are put out first at the tip of the tassel and fresh ones come 
 out every morning for several days. It is necessary to remove all 
 
CROSSED CORX 
 
 175 
 
 the tassels from all plants of one kind before the anthers can be 
 seen. If pulled too soon the tassel sometimes breaks, leaving a 
 portion in the plant which will later grow out and give off pollen. 
 If all of the tassels of one kind of plants are removed at the 
 proper time all of the seeds produced on these plants must be 
 cross-pollinated with the other strain. This is the seed to be used 
 for field planting and will give vigorous and uniformly produc- 
 tive plants. Seed from the pollinator rows is all inter-pollinated 
 and can be used for stock seed for planting in the crossing plot 
 
 Fig. 20. — A field in which crossed seed corn is produced. Two 
 rows are detasseled while every third row, planted with a different lot 
 of seed, furnishes the pollen. 
 
 next year. By maintaining two crossing plots in separate fields, 
 detasseling one type in one field and the other type in the second 
 field, it is possible to have inbred stock seed of both types pro- 
 duced each year. 
 
 Crossing can be made either way as far as the product from the 
 crossed plants is concerned. Reciprocal crosses in corn give 
 results that are closely, if not exactly alike. Usually, however, 
 it is desirable for one reason or another to make the cross one 
 way. Some strains make better seed than others while a strain 
 that may be poorer as a seed parent may be better as a pollen 
 parent. If this is the case a small plot of the seed parent can be 
 
i 70 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 273 
 
 grown in a field by itself to produce stock seed for planting" in 
 the crossing" plot. 
 
 It is very important to maintain the stock seed of the two in- 
 bred types free from any outcrossing with any other corn. 
 Pollen is blown by the wind for long distances. Fields that are 
 500 or more feet apart and not in the line of the prevailing, winds 
 will not show much mixing especially if they are separated by a 
 barrier of trees or other windbreaks. 
 
 Fig. 21. — Two inbred strains showing uniformity of ear type. 
 
 Fortunately, when inbred plants are crossed with any unre- 
 lated kind of corn there is such a noticeable increase in the size 
 of the crossed plants and change in type that is usually possible 
 to detect such outcrosses and remove them before they produce 
 pollen. In order to do this it is necessary to go through the cross- 
 ing fields and rogue both the seed parent and pollen parent very 
 carefully just before the tassels appear. It is best to remove or 
 destroy the whole plant so that seed from them will not get mixed 
 in with the stock strains. 
 
CROSSED CORN 
 
 177 
 
 Generally it will be found desirable to have the seed parent 
 early in order to have the crossed seed for field planting well 
 matured. The pollen parent can be later since pollen usually 
 comes out well in advance of the silks. A small difference in 
 this order will bring the two together at just the right time. 
 
 If there is much difference in time of silking and tasseling" 
 betwetu the two parental stocks it is necessary to plant the two 
 at different times. It is often difficult to know the right time to 
 plant as the time of flowering varies with the season and changes 
 unequally with different strains. 
 
 Fig. 22. — Crossing the two inbreds gives size and retains uniformity. 
 
 Two weeks difference in planting time will not make more than 
 four or five days difference at pollinating time as the late planted 
 corn tends to catch up with the early. However, if a drv spell 
 or other unfavorable growing conditions intervene the later plant- 
 ing may not come on as fast as normally whereas the earlier 
 planted corn may not be as much affected. For this reason it is 
 advisable to plant the pollen parent at two different times, from 
 ten days to two weeks apart. When the seed parent and pollen 
 parent flower at about the same time a good plan is to plant all of 
 the seed parent and half of the pollen parent at one time, leaving 
 every other row of the pollinator to be planted ten davs or two 
 weeks later. 
 
 With vigorous corn it is not necessary to have the pollen-produc- 
 ing plants in every other row. One pollinating row to two, three 
 or even four detasseled rows is sufficient depending on the amount 
 
i 7 8 
 
 CONNECTICUT EXPERIMENT STATION 
 
 BULLETIN 273 
 
 of pollen produced and the duration of the flowering period. 
 This must be determined by trial for each particular combination 
 and the field in which it is grown. 
 
 SINGLE CROSSES. 
 
 Hybrids produced by combining 1 two fixed inbred strains are 
 called single crosses and have the greatest uniformity and true- 
 ness to type in the first generation of any type of crossed corn. 
 
 Fig. 23. — Crossed corn showing evenness in height and tassel formation. 
 
 Where uniformity in size, shape and other ear characters and 
 evenness in ripening are particularly important, as in sweet corn 
 for market gardening and canning, it will probably be well worth- 
 while to use this method in spite of certain serious handicaps. 
 
 The principal difficulty of producing single crosses is the low 
 yields and poor quality of the seed obtained from the weakened 
 inbred plants. No inbred strains have been produced that will 
 yield much more than half as much as the original variety when 
 dependent upon their own pollen or pollen from other inbred 
 strains. They also make a much smaller amount of pollen, and 
 unless the two strains are planted at just the right time so that 
 
CROSSED CORN 
 
 J 79 
 
 pollen will be given out as soon as the silks appear, and continue 
 until all the silks are out, the amount of crossed seed produced 
 will be very low. 
 
 Fig. 24. — All of the ears ripen at the same time. 
 
 Inbred strains are also slower in ripening, and the thorough 
 curing, so necessary to insure strong germination, is difficult 
 to obtain. 
 
180 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 The success of single crossing" will depend very largely on the 
 production of inbred strains which are sufficiently vigorous and 
 productive to. make a fair yield of seed. Since corn is being 
 inbred very extensively there is every prospect that such inbred 
 strains will soon be forthcoming and that this method can be used 
 satisfactorily with sweet corn for market gardeners and canners. 
 
 DOUBLE CROSSES. 
 
 A further development of the method of crossing has been 
 made which overcomes the handicap of low production and poor 
 quality of seed of the first method. This is to cross two first 
 generation hybrids. In this way four different inbred strains 
 are combined by three crossings as follows: 
 
 Inbred Strains A 
 
 Single Crosses A 
 
 Double Cross 
 
 The two crosses of inbred strains are made as described above. 
 The two different lots of crossed seeds are planted in alternating" 
 rows in the same way and all the plants of one lot are detasseled 
 in the same way as before. The seed produced on the detasseled 
 plants is used for field planting. The seed from the plants that 
 produced the pollen is of no further value either for field planting 
 or for stock seed and must be discarded. 
 
 The two single crosses being vigorous and productive, a good 
 yield of high quality seed is obtained. The crosses produced in 
 this way by one hybrid type pollinated by another are no less 
 productive than either parent and production may even be appreci- 
 ably increased. 
 
 It is important to test the combinations first but when a high 
 yielding and desirable double cross is once produced it can always 
 be reproduced by combining the same strains in the same way. 
 
 It is essential that the four inbred strains be of such constitu- 
 tion that they will give good results in all combinations when 
 crossed singly, particularly the crosses AC, AD, BC and BD. 
 The combinations AB and CD should also grow well to give a 
 good yield of seed. The four strains may all come from the same 
 variety or from different varieties. In the latter case the two 
 strains which form the seed parent should come from one variety 
 and the two to form the pollen parent from the other. 
 
 Double crosses are not as uniform as single crosses either in 
 height of plant, size and shape of ear, or in time of maturity- 
 
CROSSED CORN 
 
 Fig. 25. — Illustrating by actual field results the bring- 
 ing together of four inbred strains by three crossings 
 to produce double crossed corn. 
 
1 82 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 This is due to the fact that the first generation hybrids used for 
 the seed and pollen parents are all producing ovules and pollen 
 grains of unlike germinal constitution. However, all of the 
 double crossed plants result from hybrid combinations. There is no 
 opportunity for weaknesses to appear due to inbreeding. Hybrid 
 vigor is therefore kept at the maximum and may even be increased. 
 For that reason every plant is strong and sturdy and each one 
 produces a good ear if given an equal chance to grow. 
 
 In field corn where uniformity is not so important the greater 
 variability of double crosses may be an advantage in giving the 
 plants a greater adaptiveness to different seasons and soils. All 
 of the plants will not be at the same critical stage of development 
 at some unfavorable period and may escape injury that would 
 seriously damage a more uniform lot of plants. 
 
 The productiveness of a double cross compared to the single 
 crosses and the original varieties is shown in the following com- 
 bination of inbred strains self-fertilized four years, two strains 
 from Century Dent and two from Learning. Both varieties have 
 been grown for many years in Connecticut, are well adapted to 
 local conditions and are among the highest yielding of all the 
 varieties tested at Mt. Carmel and at Storrs. 
 
 Variety or Cross Yield in Bu. per Acre 
 
 Century Dent, no 47.5 
 
 Learning, 112 44.4 
 
 Inbred Century Strain, 110-2 15.3 
 
 Inbred Century Strain, 110-4 16.8 
 
 Inbred Learning Strain, 112-1 42.7 
 
 Inbred Learning Strain, 112-4 11.1 
 
 Single Cross, 110-2x110-4 51.2 
 
 Single Cross, 112-1x112-4 45-6 
 
 Double Cross (no-2x 110-4) x (112-1 x 112-4) . 69.8 
 
 The figures represent averages of from two to six plots of each 
 lot. The yields have been corrected for soil differences according 
 to results from the adjoining check plots and all are based on a 
 uniform moisture content of 12 per cent. The double cross gave 
 over 50 per cent more grain than the average of the two 
 parental varieties. 
 
 The yield of one of the inbred strains is unusually high, nearly 
 equalling the variety from which it was derived. The quality of the 
 inbred corn was poorer than the variety and this yield was 
 obtained in a field where there was an abundance of pollen. When 
 planted in a separate field and dependent on its own pollen or 
 pollen from another inbred strain it would probably not yield 
 so high. 
 
 A combination of two inbred strains of Burr's White Dent and 
 two of Learning, both varieties originally from Illinois, has been 
 found to give a large and vigorous stalk growth and generally 
 
CROSSED CORN 
 
 l8 3 
 
 a higher yield of grain than any variety of corn grown in southern 
 Connecticut. This particular combination is called Double Crossed 
 Burr-Learning and seed has been grown commercially since 192 1. 
 From 1918 to 1922 it was tested at Mt. Carmel in comparison 
 with all of the varieties commonly grown in Connecticut and the 
 yields are given in the first part of this bulletin. 
 
 This combination yielded more than all varieties in three out 
 of the five years tested, while no one variety yielded more than 
 
 Fig. 26. — Double Crossed Burr-Learning'. 
 
 the others in more than one year. The greater return from Burr- 
 Learning is not only in the larger yield, but also in the freedom 
 from mold, fewer nubbins and less soft corn. In addition the 
 plants have a noticeable ability to stand erect when other varieties 
 are blown down, and show a marked tendency to hold their foliage 
 green until the seeds are ripe. 
 
 Although this new kind of corn will not out-yield all varieties, 
 everywhere, in each season, it has been tested sufficiently under 
 farm conditions to show that it can be planted profitably in 
 many places. 
 
I.84 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 Double crosses, like single crosses, will not maintain their high 
 yields more than one year after the cross. From a field of 
 Double Crossed Burr-Learning that yielded well over one hundred 
 bushels of shelled grain per acre, about one bushel of the largest 
 and finest ears were selected. These were shelled together and 
 this second generation seed was planted the following year in 
 comparison with first generation seed. Two plots averaged 73.5 
 bushels in comparison with 95.1 bushels for the freshly crossed 
 seed. This is a loss in grain of 23 per cent. The stalks grew 
 vigorously and from the appearance in the field it seemed to be 
 as productive as the first cross but at harvest time it was seen 
 that many plants failed to make a good ear. 
 
 MULTIPLE CROSSES. 
 
 The principal objection to the method of double crossing is the 
 necessity of maintaining four inbred strains of corn free from 
 outcrossing with each other or other types of corn and making 
 three separate crosses. 
 
 Theoretically, the same combinations of factors and in the same 
 proportions can be secured by crossing the second generations 
 from the two single crosses as by crossing the two first genera- 
 tion hybrids. A two years test shows that in the case of the 
 Burr-Learning combination the second generation of the Burr 
 White single cross by the second generation of the Learning 
 single cross gives the same yield and quality of corn as the com- 
 bination of the first generations of those two crosses. The yield 
 and quality of the seed itself produced by second generation plants 
 is not so good but the crop grown from that seed is in every way 
 equal to the combination of the two first generation hybrids. 
 
 These results led to "multiple crosses," a further step in the 
 evolution of crossed corn. A number of the best inbred strains 
 of a variety are permanently combined into a fairly uniform type 
 that can be propagated from year to year by natural inter-crossing, 
 as are ordinary varieties. In other words, a "re-created" variety 
 is produced in which all the best of the old variety has been com- 
 bined and all the inherited abnormalities and weaknesses have 
 been eliminated. 
 
 This recreated variety is now crossed with a similar combina- 
 tion of the best inbred strains from some other sort or perhaps a 
 group of inbred strains of different type from the same variety. 
 
 Such a multiple cross would have the advantage of producing 
 good yields of well developed seed and crossing each year would 
 give maximum vigor and productiveness. This method has not 
 yet been thoroughly tested but preliminary tests indicate that it 
 will be feasible. The uniformity of the crossed plants produced 
 
CROSSED CORN 
 
 iSc 
 
 by this method may not be as great as in a double cross, but if 
 the right combination of strains is made, yield should be maintained 
 at a high level indefinitely. 
 
 MODIFIED SINGLE CROSSES. 
 
 Greater uniformity, where this is desirable, can be obtained by 
 combining a number of strains from one line descending from a 
 
 Fig. 27. — The uniform size and shape of ear and even ripening are 
 important factors in sweet corn for market gardening and canning. 
 
 single plant but separated in the first or second generation and 
 self-fertilized four or five years to rid them of recessive weaknesses 
 and undesirable characters. Combining several of these sub- 
 strains gives vigor and productiveness closely approaching the 
 original variety and such a combination could be propagated from 
 
lS6 CONNECTICUT EXPERIMENT STATION BULLETIN 273 
 
 year to year by natural inter-pollination, at the same time main- 
 taining" a fair degree of fixity of type. 
 
 When crossed with a similar combination of sub-strains descend- 
 ing from a different plant of the same or a different variety 
 yield and vigor would be as great as in any system of crossing 
 and the uniformity of the hybrid in certain combinations would be 
 nearly as pronounced as in straight single crosses of two fixed 
 inbred strains. 
 
 Crossed seed for field planting would be made each year. The 
 yield and quality of the seed would be better than that produced 
 by single inbred strains and nearly equal in these respects to the 
 method of double or multiple crossing. 
 
 UNIFORMITY AND YIELD. 
 
 In all of these methods of crossing one must compromise 
 between the uniformity of the crossed corn on the one hand and 
 the vigor and productiveness of the stock strains used in making 
 the cross on the other. 
 
 Where uniformity is of great importance it will be best to use 
 the method of crossing two fixed and uniform inbred strains. 
 Where trueness to type is not so important, as in field corn for 
 grain or silage, maximum yields can be obtained, at a lower cost, 
 by double crosses or multiple crosses. 
 
 In all systems of crossing inbred strains the variability of the 
 crossed corn is no greater than is now present in all varieties of 
 corn and is frequently less because every plant is vigorous and 
 productive and much poor corn that is usually harvested from 
 every field is largely eliminated. 
 
 NECESSITY OF USING CROSSED SEED. 
 
 All of these methods of crossing may seem complicated to those 
 who are not familiar with the development of corn breeding - prac- 
 tices. It is only necessary to remember, however, that two sepa- 
 rate strains of corn must be maintained free from mixing with 
 each other or any other kind of com and that these two types 
 must be planted in alternating rows and all the plants of one of 
 them detasseled before pollen is shed. The seed produced 
 on these castrated plants is used for planting to produce 
 crossed corn. 
 
 The experience of twenty years indicates clearly that the largest 
 yields together with the greatest uniformity and fixity of type 
 adapted to particular requirements can only be obtained by some 
 system of crossing. Furthermore the evidence is conclusive that 
 
CROSSED CORN 1 87 
 
 these crosses will not maintain their high yields and other desirable 
 qualities in later generations, so that to secure the benefits of 
 hybrid vigor it is necessary to plant crossed seed every year. 
 
 COST OF SEED CORN. 
 
 It requires about ten bushels of potatoes to plant an acre., about 
 two bushels of oats and a bushel and a half of wheat for a 
 similar area. 
 
 Depending upon the size of the kernels and the rate of planting 
 a bushel of corn will plant from four to seven acres. For dent 
 corn five quarts of seed is usually ample for each acre. 
 
 While the value of seed corn is somewhat more in proportion 
 to the market value of the grain for corn than other commonly 
 cultivated crops, the cost per acre of the seed is the lowest of the 
 list, and compared to the other expenses of growing a crop of 
 corn, the preparation of the soil, application of fertilizers, fre- 
 quent cultivation, husking out or cutting up for silage, the cost of 
 the seed becomes almost a negligible item. 
 
 For this reason the outlay for seed may be considerably 
 increased, even doubled or tripled, and still be repaid many times 
 over if the high priced seed gives an appreciable increase in yield 
 or improvement in quality. 
 
 Crossed corn can do this. It has been tested long enough to 
 show that, when the right combination is obtained, one which is 
 adapted to the locality in which it is to be grown, it will easily 
 pay for the increased cost of the seed, and leave a margin of 
 profit as well. 
 
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