iB 249 A42 ‘opy 1 U. S. DEPARTMENT OF AGRICULTURE. BUREAU OF PLANT INDUSTRY—BULLETIN NO. 111, PART II. SB 249 B. T. GALLOWAY, Chief of Bureau. A42 Copy 1 THE FIBERS OF LONG-STAPLE UPLAND COTTONS. . ‘ ‘) " j H’ A.” ALLARD, Screntiric Assistant, CorTron BREEDING INVESTIGATIONS. ISSUED SEPTEMBER 9, 1907. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1907. Monogr2p" CO NEE Notes cy! | | Page. ; pon (GC) Wa 0 O_o ee oe a a a sah Wkneds watewae it ae ent lack of uniformity and its occurrence..........--- ae cme ai eae 5 rue nature of the longer fibers...............-..---- RE A yyhe at 6 at r ILIDSTR AT TONS ae PLATES. Puate I. Cotton seeds with fibers attached. A and 6.—Cotton seeds with fibers combed out to show uniformity and nonuniformity in the length of the fibers. @—Lock of Griffin cotton stretched so as — to show points of origin of longer fibers...-.........----------- II. Seeds of cotton combed out to show the so-called longer fibers. — A.—Columbia variety. B.—Griffin variety -.--..- aSoreeeeemeeee 7 TEXT FIGURES. va Fia. 1. Single cotton fibers from the so-called longer group of fibers........-- 2. A few extra-long cotton fibers, showing two fibers united. aap eet. 3. Cotton fibers tied together, very much magnified....... (ae ceoae eee ‘ 111-11 ; 4 PLATE Aand BP. —Cotton seeds with fibers combed cott COTTON SEEDS WITH FIBERS ATTACHED. it to show n stretched so us to show points Ol 0 ri in the rs length of the a, b, ¢ fibers. ( -—Lock of Griffin Bul. 111, Pt. Il, Bureau of Plant Industry U. S. Dept. of ° PLATE II. SEEDS OF COTTON ComBED OUT TO SHOW THE SO-CALLED LONGER FIBERS. A.—Columbia variety. 2.—Griffin variety. B. P. I.—305. THE FIBERS OF LONG-STAPLE UPLAND COTTONS. UNIFORMITY OF COTTON FIBERS. In investigations in cotton breeding where an improvement in cer- tain lint characters is desired several factors must be carefully consid- ered. Among these, some of the most important are fineness of lint, the relative yield of lint to the total yield of seed cotton, and the uni- formity of length of all the fibers when properly combed out and examined. The last character, uniformity of length, is a most impor- tant one and has much to do with subsequent waste and the produc- tion of good yarns in the process of manufacture. On Plate I are illustrations of cotton seeds with fibers combed out to show uniformity and nonuniformity in the length of the fibers. The seeds to the left (A) show very poor uniformity and are of the “butterfly” type, as they are commonly called. In marked contrast, the seeds to the right (B) show excellent uniformity as a result of several generations of careful selection. APPARENT LACK OF UNIFORMITY AND ITS OCCURRENCE. There is an apparent lack of uniformity which deserves consider- able attention from the standpoint of cotton growers and breeders. Plate II illustrates this character, although it is more strikingly brought out in the operation of detaching the seed from the lock. From the illustration there would appear to be a great lack of uni- formity, due to a group of fibers about twice the length of the general covering. This group arises from the center of the main body of fibers or, often, from those having a point of attachment near the larger end of the seed. This character is usually associated with the finer, more crinkly types of long-staple cottons, such as the fine, long- linted Egyptian and Sea Island varieties and the long-staple Upland varieties—Griftin, Allen, Cook, ete. It is a character which becomes more apparent as a variety is being rigidly selected generation after generation for finer, longer staple. This has been well illus- trated in the improvement of the lint characters of the Russell variety and, to some extent, the Jones variety. The orginal condition 1-11 0 6 THE FIBERS OF LONG-STAPLE UPLAND COTTONS. of both of these varieties is remarkably free from this so-called longer group of fibers. In the case of the greatly improved Russell strain, which has become distinctive enough in good lint characters and yield to be designated as a new variety—the so-called Columbia cotton—- these longer fibers are evident to a remarkable degree. THE TRUE NATURE OF THE LONGER FIBEBS. It has been more or less the rule with cotton breeders and cotton growers acquainted with the requisites of desirable lint characters to regard these extra-long fibers as an unfavorable feature. In this light they meant a variation toward nonuniformity. In the work of selec- tion, to avoid as much as possible a perpetuation of this sort of varia- tion, plants showing this character most markedly were regarded with suspicion and later even discarded, although ~~~ ~~~ in other respects they were among the best in Pa Le RG Oe fp Cee yes eee the field. ba aS A careful examination leads to the conclusion eo EE » . eae ee Oe) that these fibers should be regarded in a wholly OEE OCR af different light. They are not longer Jibers as Stith awe been generally considered, but are Fig. 1Single cotton fibersfrom caused by more or less curling and interweaving, pao longer group of qhich results in the pulling out of fibers from adjacent seeds. In the ordinary manner of stretching the locks to determine the drag, the fibers are slowly separated and drawn out, and at those points of greatest binding, as shown in Plate I, C, a, 4, and c, the groups of longer fibers appear to rise. If, now, a single seed is selected and detached from the rest and the entire group of fibers loosened from its attachment to the seed See eee coat in the neighborhood of ——. the longer groups, onecan = \J-~~)—~___~_4+__ ~~ with fine forceps draw these $7 BU ee ee fibers out carefully and com- pare their lenoth with those." =" 4 ee of the rest of the seed. eee eee In manyinstances the sin- 1, = Sea gle fibers now readily sepa- Fig. 2.—A few extra-long cotton fibers, showing two rate, since the tension of ia iti pulling has ceased. Several of these single fibers are shown in figure 1. In some instances fibers nearly twice the normal length are drawn out. Oftentimes with the naked eye the point of union or tying may be discerned by the tiny loose ends, as is shown in figure 2. In other cases, however, this point of union is so intimate that only a high microscopic power can make it evident. Figure 3 illustrates various 111-11 THE TRUE NATURE OF THE LONGER FIBERS. 7 degrees of this tying or curling together, as seen when greatly mag- nified. In figures 1 and 2 single and united fibers, respectively, of natural length are shown, but the diameters are of necessity much greater than normal, owing to the exceeding fineness of the fibers. The drag of cottons showing the longer fibers previously described gives a more extended, elastic tension than is manifest among the short-staple varieties. It is probable that breeders may find this character a useful one in indicating a tendency toward increased length, fineness, and crinkliness of staple in the individuals in which it occurs most noticeably—an indication of better spinning quality. It isimportant that breeders and grow- ers of long-staple cottons should know that these apparently longer fibers are no indication of true lack of uniformity. The presence of these fibers in the long- staple Upland varie. ties has quite univer- sally led to the erro- neous belief that such cottons are rather inferior in uniformity as regards length of fibers. The Griflin cotton, in particular, recognized in other respects as the best long-staple Upland cotton grown, has always been described as decidedly unsatis- factory so far as uniformity in length of staple is concerned, since the drawing out of fibers from adjacent seed is a marked characteristic of this variety. A knowledge of the true nature of these longer fibers will clear the reputation of some of the best long-staple Upland varieties of a seri- ous fault hitherto wrongly attributed to them by all breeders and growers. Fic, 3.—Cotton fibers tied together, very much magnified. 111-11 O ite 0 020 948 048 7