TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS, Director College Station, Texas BULLETIN NO. 697 OCTOBER 1947 Cleaning Quality of Raw Cotton as Aflected by Physical Properties of Fibers MARY ANNA GRIMES, Textile and Clothing Specialist Department of Rural Home Research LIBRARY A A. a M. COLLEGE or TEXAS AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS GIBB GILCHRIST, President J18-1 147-4500-L180 Preface The amount of cotton which is mechanically harvested is increas- ing each year as efforts are being made to lower the costs of produc- tion through mechanization. Mechanically harvested cotton contains more trash than hand-picked cotton. Trash determines to a consid- erable degree the grade and price of cotton. The trash content must, y therefore, approach that of hand-picked cotton, or the lower grade and price may offset much of the saving made through mechanical harvesting. Hence, the cleaning quality of raw cotton is becoming of greater importance. Varieties of cotton differ in cleaning quality, some giving up much higher percentages of trash than other varieties. Information as to the causes of these differences may be of value to all those concerned with cotton production and manufacture. - A This is a report of a study of the effect of fiber properties on the cleaning quality of 84 cottons. Varieties grown at College Station and Lubbock during 3 seasons and harvested by a mechanical stripper were used. Length, fineness, strength and maturity of the fibers, classer’s grade and staple, and the waste were determined. It was found that the fiber property which had the most effect on cleaning was thickness of the cell wall, frequently called maturity. Although long, fine cotton is more difficult to clean than short, coarse cotton, this difference was found to be due to the greater percentage of thin-walled fibers which generally occurs in long, fine cotton rather than to the greater length and fineness of the fibers. Fibers with thin walls are finer by weight per unit length than those with thick walls. There are more thin-walled fibers when grown during seasons of heavy rainfall or irrigation than during normal seasons. Wet seasons result in greater plant growth, more trash is harvested with the cot- ton, and more thin-walled fibers are formed, all of which contribute to the difficulty of cleaning the cotton. The inter-seed fiber drag (resistance fibers offer to seed separation) , apparently does not affect the cleaning quality. - The cleaning quality was not affected by the strength of the fibers. There was an increase in waste with an increase in height of the plants at Lubbock but not at College Station, perhaps because there was less variation in the plant heights at College Station. It seems possible that the kind of trash may have more effect on the cleaning quality of cotton than do the fiber properties, a possi- bility which needs further study. CONTENTS PAG i Preface . . . . . . . . . . . . . . . . . . . . ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ‘IA Source of Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methods of Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Comparisons between Stations, Seasons and Varieties . . . . . . . . . . . . . . . . 6» Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 p‘ Seasons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13p Varieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Relationship between Waste and Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 T Relationship between Waste and Classer’s Staple . . . . . . .6 . . . . . . . . . . . . . . 19 Correlation between Waste, Grade and Fiber Properties . . . . . . . . . . . . . . . 20S Fiber Drag and Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22’ Plant Height and Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22a; College Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 .Lubbock .................................................... .. 24; Rainfall and Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 College Station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 j Lubbock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Elfect of Method of Harvesting on Fiber Properties . . . . . . . . . . . . . . . . . . 26 I Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 a Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 i V BULLETIN NO. 697 OCTOBER 1947 Cleaning Quality of Raw Cotton as Aflected by the Physical Properties of the Fibers MARY ANNA GRIMES, Textile and Clothing Specialist Department of Rural Home Research iii Efforts to lower the cost of producing cotton are resulting in greatly accelerated efforts to mechanize all phases of cotton produc- tion. Mechanical harvesting increases the amount of trash harvested with the cotton over that harvested by hand picking. Trash is of prime importance in determining the grade of cotton since it is one of the three factors which chiefly determine grade, therefore, af- fecting the price of cotton. The trash content of mechanically har- vested cotton must approach that of hand-picked cotton to mini- mize a reduction in grade and price of cotton lint. Thus, the prob- lem of cleaning increases in importance as mechanical harvesting increases. Cottons vary widely in the extent to which they give up trash. It has been found that cottons grown, harvested, cleaned and ginned under identical conditions, differ as much as three grades between types Such a spread between grades has resulted in a differ- ence of $30 or more per bale. i‘ It was thought probable that these differences in cleaning qual- ity might be affected in different degrees by the various physical properties of the fiber. Knowledge of the relative importance of fiber properties in cleaning cotton should be of value to all those who are concerned with cotton breeding, production, harvesting, ginning and manufacturing. This study was undertaken with the hope of answering some of the questions raised as to the part each of several physical proper- ties plays in cleaning cotton. Source of Material The 84 cottons used in this study were grown at the College Sta- tion and Lubbock stations during the 1941, 1942 and I943 ‘seasons. Each season the cottons at any one station were harvested on the i ‘l 6 BULLETIN NO. 697, TEXAS AGRICULTURAL EXPERIMENT STATION stated, was done with the Texas Station stripper, equipped with an i extractor which removed a portion of the trash. Ginning was on a j Io-saw gin. The cottons were classed as to grade and staple either , by j. M. Ward of the Department of Agricultural Economics and Sociology, or by a board of cotton examiners. i same day or succeeding days. All harvesting, unless otherwise‘; The data on waste in the seedcotton, plant height and fiber drag i were furnished by H. P. Smith of the Department of Agricultural Engineering. All cotton samples were furnished by Mr. Smith and A by D. T. Killough of the Department of Agronomy. The cottons from Lubbock were grown by D. L. Jones, superintendent of Sub- i station No. 8. Methods of Analyses The fiber properties which were determined, include the mean length, the upper quartile length, fineness, strength, immaturity or ~ thickness of cell Wall, and the percentage waste. Lengths were meas- ured from arrays made With a Suter-Webb sorter An average of the results of 3 arrays was used for each cotton. Fineness, which is expressed as weight per inch of fiber, was calculated either from the weights of length groups in the arrays, or by the use of a de- vice described elsewhere (3), the results from which were convert- ed into weight in micrograms per inch. Strength was measured with a Pressley breaker and is expressed as an index immaturity was determined with a polarizing microscope, or by the sodium hydroxide method, or by both methods as a part of another study (s)- The waste was removed in 2 stages: part of it from the seedcot- ton before and during ginning, and the remainder removed from the ginned cotton or lint with a Shirley analyzer (6). These wastes are expressed either as Weight or as percentage of the weight of the cotton before cleaning. Comparisons between Stations, Seasons and Varieties Stations The results of the fiber analyses and the classer’s grade and sta- ple for the cottons grown at College Station are given in Table I, and for the samples of cottons grown at Lubbock in Table 2. The averages for the 39 cottons grown at College Station and the 45 grown at Lubbock show that those grown at College Station were approximately I grade lower. There was no significant differ- ence in average length or fineness, but Lubbock cottons were slight- v-r-www- --—~ - CLEANING QUALITY OF RAW COTTON 7 i ly weaker and slightly more mature. They contained somewhat less waste and released a slightly higher percentage of waste from the seedcotton than cottons grown at College Station. ' The range and frequency for each fiber property and the differ- ences between stations may be seen more easily as summarized in Tables 3 and 4. It is seen that the 84 cottons fall within the 24/32 to 37/32 (y, l to 1 5/ 32)-inch range in staple, but that most of them, 79 per- cent, are within the 28/32 to 31/ 32-inch range with little difference between stations. The range in fineness is from very fine (below 3 micrograms per inch) to coarse (above 6), with all but 2 falling between 3.6 and 5.9 micrograms per inch. The average fineness for the College Sta- tion cottons is 4.8, and for Lubbock 4.6 micrograms per inch, clear- ly no great dilference between stations (Tables 1 and 2). There are included cottons which are slightly weak (below 8.3 strength index) through those which are of superior strength (above 9.8). Immaturities from very mature (below 22 percent immature) to very immature (over 41 percent) are represented. Only 15 cot- tons have less than 26 percent or more than 45 percent immature fibers (Table 3). Only 38 percent of the College Station but 78 percent of the Lubbock cottons contained a total waste of less than 12 grams in 1oo grams. The cottons from College Station were more evenly dis- tributed throughout the range of waste removed from the seed- cotton than were the Lubbock cottons. Of the 45 Lubbock cottons, 27, or 6o percent, fall within 2 group intervals (36-47.9 percent), as shown in Table 4. Of the College Station cottons, 18, or 46 percent, are within the range of 36-47.9 percent. One Lubbock cotton, and 8 College Station cottons fall within the range of 6 to 29.9 percent. Seven of the Lubbock cottons, but only 1 of the College Station cottons, had less than 4 percent of waste in 100 grams of lint. The greatest frequency of Lubbock cottons, 19, fall between 4 to 5.9 per- cent, but the greatest frequency of College Station cottons, 18, fall between 6 to 7.9 percent. The average total waste for the 39 Col- lege Station cottons was 13.6 grams and for the 45 Lubbock cot- tons the average was 10.6 grams (Tables 1 and 2). Comparisons between the frequencies for the 2 stations show that the 39 cottons grown at College Station are lower in grade, of ap- proximately equal length, are slightly coarser, stronger, more im- mature and contain more waste than the 45 grown at Lubbock. Table 1. Physical properties of fibers, trash removed and plant height of varieties of cotton grown at College Station during. 3 seasons Mean length Trash removed from 100 grams w ' ————-—-——-—— Length Fineness Av. a Numer- Staple Coef. of at 25% micro- Strength Imma- From From Fiber plant [-1 No. Variety ical 32nd vari- point grams index** turity seed From Total seed- From drag height p1 grade inch Inches ability inch per inch % cotton lint cotton lint grams inches a * % grams grams grams % % z 1941 U) 1 Rogers Texacala. . . .. 7.0 32 88 34 1 13 4.1 9.7 35 4.5 7.9 12.4 36 64 29.2 3 2 Duc.xLoneStar..... 7.0 30 78 29 95 5.2 9.1 37 4.8 6.6 11.4 42 58 27.0 " 3 H.&H.xAcala...... 7.0 30 72 29 91 5.4 9.2 36 5.3 5.9 11.2 47 53 25.5 H 4 Okla. Triumph . . . . . .. 7.0 29 72 33 92 5.6 8.4 39 6.3 8.2 14.5 43 57 29.2 F3 5 Meb. 804 x Meb. 140. 7.0 29 72 27 88 5.3 9.7 31 5.4 8.0 13.4 40 60 28.9 i; 6' Hi-Bred . . . . . . . . . . . .. 7.0 26 62 31 80 5.6 8.6 38 10.1 8.4 18.5 55 45 29.2 m 7 Deltapine 44-51 . . . . .. 8.0 32 86 .28 -. 1 04 4.7 9.4 35 5.3 9.0 14.3 37 63 25.5 8 Western Early . . . . . .. 8.0 30 76 32 97 4.4 8.9 39 6.0 8.7 14.7 41 59 25.2 5P 9 Gorhams Lone Star... 8.0 30 87 26 1 06 5.1 8.3 32 8.1 11.2 19.3 42 58 21.2 g 10 Regular Ducona...... 8.0 29 82 29 1 00 4.4 9.3 36 5.7 9.4 15.1 38 62 31.1 ta l1 Mebane 804-50 . . . . .. 8.0 29 74 29 92 5.6 8.4 28 6.2 7.7 13.9 45 55 28.9 Q 12 Macha . . . . . . . . . . . . .. 8.0 28 72 29 88 5.4 8.7 36 6J6 11.0 17.6 38 62 25.2 g Average . . . . . . . . .. 7.50 29 5 .768 29.7 955 5.07 8.98 35.2 6 19 8.50 14 69 42 0 58.0 173 7 27 18 g DU > 1942 F‘ r11 13 Rogers Texacala. . . . . 5.5 31 67 40 92 4.1 9.9 45 3.1 7.5 10.6 29 71 175 28 0 2g 14 Hi-Bred . . . . . . . . . . . .. 5.5 26 54 34 72 6.3 8.9 40 9.6 4.7 14.3 67 33 253 27 4 rd 15 Greer 5-3 . . . . . . . . . .. 6.0 31 77 33 99 4.4 9.8 48 1.4 7.0 8.4 17 83 200 24 9 w 16 Deltapine 14 . . . . . . . .. 6.0 30 76 34 99 4.4 9.5 36 5.5 7.0 12.5 44 56 . . . . . .. 24 5 H 17 Gorhams Lone Star... 6.0 30 72 33 93 5.4 8.9 32 2.4 6.0 8.4 29 71 . . . . . .. 26 3 a 18 Mebane 804-50 . . . . .. 6.0 29 71 30 88 5.6 8.1 27 4.5 6.0 10.5 43 57 175 30 1 m 19 Holtz . . . . . . . . . . . . . .. 6.0 29 .75 34 98 5.3 9.8 38 2.5 6.3 8.8 28 72 200 26 3 g 20 Suntex . . . . . . . . . . . . .. 6.0 28 71 37 94 5.2 9.2 33 2.2 7.7 9.9 22 78 100 29 0 21 Okla. Triumph.. .. 6.5 30 .62 37 85 5.0 8.7 42 4.9 7.6 12.5 39 61 150 24 0 V) 22 Stoneville 2 B . . . . . . .. 7.0 31 76 34 99 4.5 9.5 43 8.1 6.9 15.0 54 46 175 27 0 E 23 Western Early . . . . . .. 7.0 30 .73 32 94 4.4 9.6 36 9.3 6.9 16.2 57 43 135 26 1 a 24 Roldo Rowden . . . . . .. 7.0 30 70 34 92 5.6 8.8 28 3.1 6.9 10.0 31 69 175 26 1 0-1 25 Macha . . . . . . . . . . . . .. 7.0 29 62 34 82 5.3 8.8 41 3.8 12.5 16.3 23 77 175 24 3 o 26 Regular Ducona...... 7.0 28 73 33 .95 4.6 10.0 36 3.1 8.2 11.3 27 73 . . . . . .. 30 9 z 27 Western Meb. 140.... 7.0 24 .62 31 80 5.6 8.8 29 3.7 10.6 14.3 26 74 154 26 1 Average . . . . . . .. 6.37 29 1 694 34.0 908 5 05 9.22 36.9 4.48 7 45 11 93 35.7 64 3 172 2 26 73 Rogers Texacala. . . . . Holtz . . . . . . . . . . . . . . . Okla. Triumph . . . . . . . Roldo Rowden . . . . . . . Suntex . . . . . . . . . . . . . . Western Early . . . . . . . Regular Ducona . . . . . . Western Meb. 140.... Arkansas B 5 . . . . . . . . Gorhams Lone Star. . . Deltapine l4 . . . . . . . . . Coker's Wilds 15 .. . . . Average . . . . . . . . Average for 3 seasons. . 1 943 *The cotton grades are designated as follows: "Pressley index may be converted to strength in 1,000 l Tensile strength =(l0.8l16 X Pressley index) —0. 2. Strict Good Middling (SGM) 3. Good Middling (GM) 4. Strict Middling (SM) 5. Middling (M) 6. 7. 8. 9. Strict Low Middling (SLM) Low Middling (LM) Strict Good Ordinary (SGO) Good Ordinary (GO) bs. per square inch by the formula: 12 5.0 29 66 41 92 3.7 9.5 41 4.8 5.1 9.9 48 52 175 26.3 5.5 28 61 39 84 5.0 9.3 29 6.5 618 13.3 49 51 76 25.4 6.0 30 63 36 87 4.1 9.2 42 6.0 5.8 11.8 51 49 67 28.0 6.0 29 65 35 86 5.4 9.1 29 5.7 5.2 10.9 52 48 137 26.3 6.0 29 68 31 85 4.9 9.0 31 7.3 3.9 11.2 65 35 100 26.1 6.0 28 60 41 84 3.7 9.1 44 5.9 10.4 16.3 36 64 99 26.3 6.0 28 69 35 92 3.8 9.9 49 5.0 7.5 12.5 40 60 66 26.5 6.0 28 59 31 79 4.9 8.9 32 6.7 4.9 11.6 58 42 147 28.1 6.0 26 56 43 82 4.6 8.9 38 6.4 7.4 13.8 46 54 94 25.8 6.5 28 61 42 89 3.7 9.5 41 7.5 7.5 15.0 50 50 60 19.8 7.0 28 69 38 85 3.9 9.0 40 5.7 11.8 17.5 33 67 97 26.1 7.5 35 83 39 1 10 2.9 9.9 50 14.2 15.5 29.7 48 52 . . . . . .. 28.4 6.12 28. .650 37.6 .879 4.22 9.28 38.8 6.81 7.65 14.56 48.0 52.0 111.9 26.09 6.64 29.1 .703 33.8 .914 4.80 9.16 37.0 5.72 7.84 13.56 41.4 58.6 148.1 26.67 NOLLOO MVH e10 LLYIVIID DNINVEITD Table 2. Physical properties of fibers, trash removed and plant height of varieties of cotton grown at Lubbock during 3 seasons Mean length Trash removed fi-om 100 grams ——i——-—-—--— Length Fineness Av. Numer- Staple Coef. of at 25% micro- Strength Imma- ~ From From Fiber plant No. Variety ical 32nd va - point grams index" turity seed From Total seed- From drag height grade inch Inches ability inch per inch % cotton lint cotton lint grams inches * % grams grams grams % % 1941 40 Lock. Mebane 140.... 4.5 29 .73 26 .88 5.6 9.2 35 3.7 3.7 7.4 50 50 . . . . . .. 24.0 40 Hi-Bred . . . . . . . . . . . .. 5.0 29 .75 27 .91 5.4 8.2 31 3.6 5.9 9.5 38 62 . . . . . .. 20.8 42 H.&H.x Acala..... 5.0 28 .72 32 .92 5.5 8.3 34 0.5 6.9 7.4 7 93 . . . . . .. 24.1 43 DuconaxLone Star.. 5.5 30 .85 30 1.03 5.0 8.0 34 4.2 5.7 9.9 42 58 . . . . . .. 20.0 44 Deltapine . . . . . . . . . .. 6.0 31 .82 38 1.05 4.5 8.4 34 4.4 5.2 9.6 46 54 . . . . . .. 26.7 45 Western Early . . . . . .. 6.0 30 .84 30 .90 4.4 8.7 33 5.7 5.7 11.4 50 50 . . . . . .. 25.5 46 Meb.804xMeb. 140. 6.0 30 .79 36 .99 4.6 9.0 32 4.7 5.4 10.1 46 54 . . . . . .. 23.5 47 ClarkxMeb.140..... 6.0 29 .73 29 .90 4.9 8.6 39 4.0 4.9 8.9 45 55 . . . . . .. 21.4 48 Ferguson 406 . . . . . . .. 6.0 29 .74 31 .92 5.6 7.1 32 4.2 4.8 9.0 47 53 . . . . . .. 25.0 49 Macha . . . . . . . . . . . . .. 6.5 29 .76 28 .91 5.5 8.0 33 6.3 6.1 12.4 51 49 . . . . . .. 23.5 50 Rogers Acala . . . . . . .. 7.0 29 .89 35 1.13 4.1 9.1 37 4.6 7.0 11.6 40 60 . . . . . .. 28.6 Average . . . . . . .. 5.77 29.4 .784 31.1 .958 5.01 8.42 34.0 4.17 5.57 9.74 42.0 58.0 . . . . . .. 23 92 1942 51 Okla. Tri.xCl.xCl.. 5.0 31 .80 35 1.03 4.3 8.3 37 6.2 7.0 13.2 47 53 145 23.8 52 Mach: (Jones) . . . . . .. 5.0 30 .81 37 1.03 3.8 9.0 38 4.6 7.1 11.7 39 61 125 33.3 53 Hi-Bred . . . . . . . . . . . .. 5.0 28 .66 40 .94 4.3 8.2 40 3.3 7.5 10.8 31 69 238 34.7 54 Western Early....... 5.5 31 .75 40 1.02 3.9 8.1 42 6.8 9.4 16.2 42 58 176 37.1 55 Sh.xH.&H.!Shafter 5.5 30 .72 43 1.04 3.7 8.4 60 4.2 7.6 11.8 36 64 160 46.3 56 Mocha x Acala . . . . .. 5.5 29 .74 40 1.03 4.0 8.4 42 6.6 14.0 20.6 32 68 139 44.5 57 Lock. Mebane 140.... 5.5 29 .75 36 .98 4.3 8.2 33 3.1 5.8 8.9 35 65 160 37.9 58 Ferguson 406 . . . . . . .. 5.5 26 .72 36 .98 4.2 7.3 43 4.2 6.0 10.2 41 59 136 38.9 59 Dllc.XCl.xDuc..... 6.0 33 .81 38 1.09 4.2 8.0 35 4.6 5.8 10.4 44 56 122 34.4 60 Deltapine............ 6.0 29 .72 41 .98 4.2 8.0 43 6.6 7.4 14.0 47 53 115 37.6 61 Macha (Macha). . . . . 6.0 29 .70 38 .94 4.6 7.8 37 6.4 10.3 16.7 38 62 200 37.4 62 St.xH.&H.xSt.11 6.0 29 .68 41 .96 4.0 8.4 44 6.4 9.5 15.9 40 60 205 36.9 63 St.xH.&H.xSt.1l1 6.0 28 .68 41 .96 4.1 8.5 36 6.2 g1 14.3 43 57 137 38.1 64 H.&H.xAcala . . . . .. 6.5 24 .65 46 .97 4.0 8.0 43 6.2 .9 16.1 38 62 176 33.6 Average . . . . . . .. 5.64 29.0 .728 39.4 .996 4.11 8.18 40.9 5.38 8.24 13.63 39.5 60.5 159.6 36.75 NOILV-LS LNEINIIIEIJXEI TVHHLTHOIHDV SVXHJ. 'L69 ‘ON’. EJ311118 194$ 65 Western Early 4/63.. 4.0 30 .68 35 92 5.0 8.8 28 4.8 4.4 9.2 52 48 . . . . . . . . . . . . . . 66 Macha x Acala 6/68-98 4.0 28 73 34 95 4.9 9.1 21 3. 4 4.8 8.2 42 58 . . . . . . . . . . . . . . 67 MachaxAcala 4/5 4.0 28 56 43 79 4.3 9.3 25 3.8 6.3 10.1 38 62 . . . . . . . . . . . . .. 68 0kl.TrixClxCl3/67 4.5 28 .62 32 81 5.4 8.7 19 3.6 6.5 10.1 36 64 . . . . . . . . . . . . .. 69 Hi-Bred . . . . . . . . . . . .. 4.5 26 62 29 78 5.2 8.9 22 3.6 2.6 6.2 58 42 228 17 2 70 Rogers Acala . . . . . . .. 5.0 33 76 38 1 02 4.4 10.0 24 3.1 4.4 7.5 41 59 . . . . . . . . . . . . . . 71 H.&H.xAcala1/7.. 5.0 32 72 35 95 4.7 9.4 30 3.2 4.0 7.2 44 56 . . . . . . . . . . . . .. 72 Macha 5/40......... 5.0 29 .68 36 91 4.2 8.8 29 6.7 5.6 12.3 54 46 . . . . . . . . . . . . .. 73 West. Early x Macha 2/14 . . . . . . . . . . . . .. 5.0 28 72 33 95 5.1 9.1 21 5.6 4.4 8.0 45 55 . . . . . . . . . . . . .. 74 Clark x Missdell 3/50 5.0 28 68 36 93 4.6 8.8 24 4.2 5.5 9.7 43 57 . . . . . . . . . . . . . . 75 MachaxAcala 4/7... 5.0 28 65 38 90 4.4 9.2 29 3.8 3.9 7.7 49 51 . . . . . . . . . . . . .. 76 Western Early 4/61. . 5.0 28 68 31 89 4.8 7.9 29 3.7 4.3 8.0 46 54 . . . . . .. 77 Western Early 4/60. . 5.0 28 69 28 87 5.2 8.4 22 4.6 6.6 11.2 41 59 . . . . . . . . . . . . .. 78 Duc x Cl x Duc x Duc 5/63 . . . . . . . . . . . . .. 5.0 26 70 30 88 5.2 8.5 21 4.5 2.2 6.7 67 33 . . . . . . . . . . . . .. 79 Western Early 5/65. . 5.0 26 67 29 84 5.2 8.4 19 3.5 3.3 6.8 52 48 . . . . . . . . . . . . .. 80 West. Early x Macha _ 4/40 . . . . . . . . . . . . .. 5.0 26 61 37 83 5.0 9.3 20 3.0 4.7 7.7 39 61 . . . . . . . . . . . . .. 81 Coker’s Wilds 15..... 5.5 36 82 32 1 09 3.4 9.8 35 6.0 5.3 11.3 53 47 109 21 2 82 St.xH.&H.xSt.1/28 5.5 28 69 35 90 5.4 9.0 18 4.8 3.4 8.2 58 42 . . . . . . . . . . . . .. 83 Macha 5/25 . . . . . . . .. 5.5 26 66 32 85 4.9 8.7 28 5.0 6.8 11.8 42 58 . . . . . . . . . . . . .. 84 Deltapine 14 . . . . . . . .. 6.0 30 .72 31 95 4.2 8.8 32 7.0 3.7 10.7 65 35 128 20 3 Average . . . . . . .. 4.92 28 6 683 33 7 900 4.78 8.94 24.8 4.30 4.64 8 93 48 2 50.8 155 0 19 57 Average for 3 seasons 5.36 28 9 722 34 8 944 4.63 8.58 32.1 4.60 5.99 10 59 44 0 55. 158 8 29 87 Av. for both stations. . 5.95 28.6 .713 34.3 .930 4.70 8.85 34.3 5. 12 6.84 11 97 42 8 57.0 157 3 28 01 *The cotton grades are designated as follow: 2. Strict Good Middling (SGM) 6. Strict Low Middling (SLM) 3. Good Middling (GM) 7. Low Middling (LM) 4. Strict Middling (SM) 8. Strict Good Ordinary (SGO) 5. Middling (M) ' 9. Good Ordinary (GO) **Pressley index may be converted to strength in 1,000 lbs. per square inch by the formula: Tensile strength =(10.8116 x Pressley index)—0. 12 ll Nommoo mvu .10 zunvnb snmvcmo Z1 Table 3. Range and frequency of the length, fineness, strength and immaturity of fibers from cotton varieties grown at College Station and Lubbock ~ w If‘ Staple Mean length _ Upper quartile length g Frequency ~ Frequency L Frequency E 32nd inch College . Both Inch College Both Inch College Both g Stations Lubbock stations Station Lubbock stations Station Lubbock stations -_ E 24.0—25.0.. 1 1 .54— 59..... 3 1 4 .72- .79... 2 2 4 " 26.0-27.0“ 3 6 .so- o5“... 9 5 14 .s0~ .s7... 11 5 l6 H 28.0-29.0.. 19 24 43 .66-.7l..... 4 8 l3 21 .88— .95... l6 20 36 a 30.0-31.0.. 13 10 23 .72—.77..... 13 17 30 .96—l.03... 6 13 19 u, 32.0-33.0. 2 3 5 3 6 9 1.04-1.11... 3 4 7 m 34.0—35.0.. 1 . . . . . . . . .. 1 3 3 6 1.12-1.19... 1 1 2 36.0-37.o.. . . . . . . . . .. 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. g Total No. 39 45 84 1 39 45 84 1 Total No. 39 45 84 g ‘é . . . H Fineness Strength lndex Immaturlty q '25 Frequency Frequency Frequency F Microgram College Both Pressley College l Both Percent College Both {q per inch Station Lubbock stations index Station Lubbock stations Station Lubbock stations N '11 I31 28—3.5..... 1 1 2 7.1- 7.4.. . . . . . . . . . .. 2 2 18.0—2l.0.. . . . . . . . . . .. 7 7 '37 s 6-4.3“... s 11 25 7.5- 7.8.. . . . . . . . . . .. 1 1 22.o-25.o.. . . . . . . . . . .. s a E 4 4-5.l..... 14 16 30 7.9- 8.2.. 1 10 ll 26.0-29.0“ 6 5 11 [l1 5 2—5.9..... 15 11 26 8.3- 8.6.. 4 ll l5 30.0-33.0.. 6 8 14 z 6 0-6.7...“ 1 . . . . . . . . .. 1 8.7- 9.0.. . 12 ll 23 34.0-37.0.. 9 ll 20 l-i 9.1- 9.4.. 9 8 17 38.0-41.0.. 10 3 13 m 9.5- 9.8.. 8 1 9 42.0-45.0. 5 6 ll lq 9.9—l0.2.. 5 1 6 46.0-49.0. 2 . . . . . . . . .. 2 l> 50.0-53.0. . . . . . . . . . . . . . . . . . . .. 1 g3 Total No. 39 45 84 Total No. 39 45 84 Total No. 39 45 84 g CLEANING QUALITY OF RAW COTTON l3 1* Table 4. Range and frequency of grade and waste of cotton grown at College Station and Lubbock Grade Total waste Frequency Frequency Numerical ' , grade Colle ge Both Percent College Both i Station Lubbock stations Station Lubbock stations ;sM a s-4.4 . . . . . . . .. 3 s 6.0-1.9 . . . . . . . .. 9 9 'M 4.5-5.4 1 19 20 8.0- 9.9 5 l2 17 SLM 5.5-6.4 16 20 36 10.0-11.9 10 14 24 LM 6 5-7.4 15 3 18 12.0—13.9 8 3 ll 8G0 7 5-8.4 . . . . . . . .. 7 14.0-15.9 8 3 11 16.0-17.9 5 3 8 18.0-19.9 2 . . . . . . . . . 2 20 . 0-21 . 9 . . . . . . . . . 1 1 251114.119" 1 . . . . . . . .. 1 i Total No. 39 45 84 Total No. 39 45 84 Z Waste removed from seed cotton Waste in 100 grams lint Frequency i Frequency Percent College Both . Percent College Both Station Lubbock stations Station Lubbock stations E a 6.0-11.9 . . . . . . . .. 1 1 2.0- 3.9 1 7 8 12.0-17.9 1 . . . . . . . .. 1 4.0- 5.9 6 19 25 18.0-23.9 2 . . . . . . . .. 2 6.0- 7.9 l8 13 31 24.0-29.9 5 . , . . . . . . .. 5 8.0- 9.9 7 4 ll 30.0-35.9 2 5 7 10.0-11.9 5 1 6 36.0-41.9 9 12 21 12.0-13.9 l . . . . . . . .. 1 42.0-47.9 9 15 24 14.0-15.9 1 1 2 48.0-53.9 5 7 12 54.0—59. 9 4 3 7 60 . 0— 65. 9 1 1 2 66.0—71 .9 1 1 2 3 Total No. 39 45 84 Total No. 39 45 84 Seasons Since 6 varieties at College Station and 5 at Lubbock were grown each of the 3 seasons, it is possible to compare differences due to the season (Tables 5 and 6). In 5 of the 6 varieties grown 3 seasons at College Station, there is a difference of 2 grades and in 1 (Oklahoma Triumph) a difference of 1 grade due to season (Table 5). In all 6 varieties, the grade is higher for 1943 than for 1941. In 4 of these 6 varieties there is more waste in 1941 than in either 1942 or 1943. All varieties grown at both stations for 3 seasons, with 1 excep- tion, were finer in 1943 than in 1941, with less difference between 1941 and 1942. Of the 6 varieties grown 3 seasons at College Station, those grown in 1941 were most mature followed by those grown in 1942 and 1943 respectively (Table 5). Of the 5 varieties grown 3 seasons at Lubbock, those varieties grown in 1943 were most mature followed by those grown in 1941 and 1942 respectively (Table 6). Table 5. Physical properties of fibers, trash removed and plant height of 12 varieties of cotton grown each of 2 or 3 seasons at College Station F‘ a Mean length Waste from 100 grams U008)‘ Fi‘ Average w Numer- Staple quartile micro- Strength Imma- Removed plant c; Variety Season ical 32nd length grams index turity Total from Removed Wt. in h ght y: grade inch inches Inch c. of v. per inch weight seed from 100 gms. inche b o % removed cotton lint of lint b! grams % % grams fi 1941 7.0 32 1.13 .88 34 4.1 9.7 35 12.4 36 64 7.9 29.2 z Rogers Texacala 1942 5.5 31 .92 .67 40 4.1 9.9 45 10.6 29 71 7.5 28.0 2e 1943 5.0 29 .92 .67 41 3.7 9.5 41 9.9 48 52 5.1 26.3 .0 Average 5.8 31 .99 .74 38.3 3.97 9.70 40 11.0 37.7 62.3 6.8 27.8 ff: 1941 7.0 29 .92 .72 33 5.6 8.4 39 14.5 43 57 8.2 29.2 h] Okla. Triumph 1942 6.5 30 .85 .62 37 5.0 8.7 42 12.5 39 61 7.6 24.0 H 1943 6.0 30 .87 .63 36 4.1 9.2 42 11.8 51 49 5.8 28.0 E Average 6.5 30 .88 .66 35.3 4.90 8.77 41 12.9 44.3 55.7 7.2 27.1 Z 1941 8.0 30 .97 .76 32 4.4 8 9 39 14.7 41 59 8.7 25.2 Q Western Early 1942 7.0 30 .94 .73 32 4.4 9 6 36 16.2 57 43 6.9 26.1 a 1943 6.0 28 .84 .60 41 3.7 9 44 16.3 36 64 10.4 26.3 a Average 7.0 29 .92 .70 35.0 4.17 9.20 40 15.7 44.7 55.3 8.7 25.9 5' 1941 8.0 32 1.04 .86 28 4.7 9.4 35 14.3 37 63 9.0 25.5 w Deltapine 1942 6.0 30 .99 .76 34 4.4 9.5 36 12.5 44 56 7.0 24.5 p 1943 7.0 28 .85 .62 38 3.9 9.0 40 17.5 33 67 11.8 26.1 b‘ Average 7.0 30 .96 .75 33.3 4.33 9.30 37 14.8 38.0 62.0 9.3 25.4 E2 1941 8.0 30 1.06 .87 26 5.1 8 32 19.3 42 58 11.2 21.2 a G. Lone Star 1942 6.0 30 .93 .72 33 5.4 8 9 32 8.4 29 71 6.0 26.3 1943 6.5 28 .89 .61 42 3.7 9 41 15.0 50 50 7.5 19.8 Average 6.8 29 .96 .73 33.7 4.73 8.90 35 14.2 _40.3 59.7 8.2 22.4 g 1941 8.0 29 1.00 .82 29 4.4 9 36 15.1 .38 62 9.4 31.1 a Regular Ducona 1942 7.0 28 .95 .73 33 4.6 10 0 36 11.3 27 73 8.2 30.9 E3 1943 6.0 28 .92 .69 35 3.8 9 49 12.5 40 60 7.5 26.5 p I-l Average 7.0 28 .96 .75 32.3 4.27 9.73 40 13.0 35.0 65.0 8.4 29.5 6 ’ _'_—_ Z Average for 1941 . . . . . . . . . . . . .. 7.7 30 1.02 .82 30.3 4.72 9.00 36 15.0 39.5 60.5 9.1 26.9 Average for 1942 . . . . . . . . . . . . .. 6.3 30 .93 .70 34.8 4.65 9.43 38 11.9 37.5 62.5 7.2 26.6 Average for 1943 . . . . . . . . . . . . . . 6.1 3.5-5 28 .88 .64 38.8 3.82 9.37 43 18.8 43.0 57.0 M Iii-Bred 1941 7.0 26 .80 .62 31 5.6 8.6 38 18.5 55 45 8.4 29.2 1942 5.5 26 .72 .54 34 6.3 8.9 40 14.3 67 33 4.7 27.4 Average 6.2 26 .76 .58 32.5 5.95 8.75 39 16.4 61.0 39.0 6.6 28.3 Meb. 804-50 1941 8.0 29 .92 .74 29 5.6 8.4 28 13.9 45 55 8.0 28.9 1942 6.0 29 .88 .71 30 5.6 8.1 27 10.5 43 57 6.0 30.1 Average 7.0 29 .90 .72 29.5 5.60 8.25 28 12.2 44.0 56.0 7.0 29.5 7 Macha 1941 8.0 28 .88 .72 29 5.4 8.7 36 17.6 38 62 11.0 25.2 1942 7.0 29 .82 .62 34 5.3 8.8 41 16.3 23 77 12.5 24.3 Average 7.5 28 .85 .67 31.5 5.35 8.75 38 17.0 30.5 69.5 11.8 24.8 Average for 1941 . . . . . . . . . . . . .. 28 .87 .69 29.7 5.53 8.57 34 16.7 46.0 54.0 9.1 27.8 Average for 1942 . . . . . . . . . . . . .. 28 .81 .62 32.7 5.73 8.60 36 13.7 44.3 55.7 7.7 27.3 Holtz 1942 6.0 29 .98 .75 34 5.3 9.8 38 8.8 28 72 6.3 26.3 1943 5.5 28 .84 .61 39 5.0 9.3 29 13.3 49 51 6.8 25.4 Average 5.8 28 .91 .68 36.7 5.15 9.55 34 11.0 38.5 61.5 6.6 25.9 Suntex 1942 6.0 28 .94 .71 37 5.2 9.2 33 9.9 22 78 7.7 29.0 » 1943 6.0 29 .85 .68 31 4.9 9.0 31 11.2 65 35 3.9 26.1 Average 6.0 28 .90 .70 34.0 5.05 9.10 32 10.6 43.5 56.5 5.8 27.6 Roldo Rowdeu 1942 7.0 30 .92 .70 34 5.6 ' 8.8 28 10.0 31 69 6.9 26.1 1943 6.0 29 .86 .65 35 5.4 9.1 29 10.9 52 48 5.2 26.3 Average 6.5 30 .89 .68 34.5 5.47 8.95 28 10:4 41.5 58.5 6.0 26.2, Average for 1942 . . . . . . . . . . . . .. .3 29 .95 .72 35.0 5.37 9.27 33 _.6 27.0 73.0 7.0 27.1 Average for 1943 . . . . . . . . . . . . .. .8 29 .85 .65 35.0 5.10 9.13 30 11.8 55.3 44.7 5.3 25.9 9|. NOLLOO AAVII JO LJLYIVIID ‘DNINVEITO 91 Table 6. Physical properties of fibers, trash removed and plant height of 10 varieties of cotton grown each of 2 or 3 seasons at Lubbock w Mean length Waste from 100 grams b‘ Upper Finenes Average i=1 Numer- Staple quartile micro- Strength Imma- Removed plant "3 Variety Season al 32nd length c. of v. grams index turity Total from Removed Wt. in height E grade inch inches Inch per inch weight seed from 100 gms. inches % % removed cotton lint of lint z grams "0 % grams 9 1941 5.0 28 .92 .72 32 5.5 8.3 34 7.4 7 93 6.9 24.1 g H. & H. x Acala 1942 6.5 24 .97 .65 46 4.0 8.0 43 16.1 38 62 9.9 33.6 ‘ 1943 5.0 32 .95 .76 35 4.7 9.4 30 7.2 44 56 4.0 . . . . . . .. g Average 5.5 28 .95 .71 3.7.7 4.73 8.56 36 10.2 29.7 70.3 6.9 28.8 E 1941 5.0 29 .91 .75 27 5.4 8.2 31 9.5 38 62 5.9 20.8 m Hi-Bred 1942 5.0 28 .94 .66 40 4.3 8.2 40 10.8 31 69 7.5 34.7 a’ 1943 4.5 26 .78 .62 29 5.2 8.9 22 6.2 58 42 2.6 17.2 g Average 4.8 28 .88 .68 32.0 4.97 8.43 31 8.8 42.3 _57.7 5.3 24.2 a 1941 6.0 31 1.05 .82 38 4.5 8.4 34 9.6 46 54 5.2 26.7 E Deltapine 1942 6.0 29 .98 .72 41 4.2 8.0 43 14.0 47 53 7.4 37.6 1943 6.0 30 .95 .77 31 4.2 8.8 32 10.7 65 35 3.7 20.3 5 Average 6.0 30 .99 .77 36.7 4.30 8.40 36 11.4 52.7 47.3 5.4 28.2 F 8 1941 6.0 30 .90 .84 30 4.4 8.7 33 11.4 50 50 5.4 25.5 a Western Early . . . . . . .. 1942 5.5 31 1.02 .75 40 3.9 8.1 42 16.2 42 58 9.4 37.1 I-g 1943 4.8 28 .88 .68 31 5.1 8.4 24 8.8 48 52 4.6 . . . . . . .. g Average 5.4 30 .93 .76 33.7 4.47 8.40 33 12.1 46.7 53.3 6.5 31.3 E 1941 6.5 29 .91 .76 28 5.5 8.0 33 12.4 51 49 6.1 23.5 H Macha 1942 6.0 29 .94 .70 38 4.6 7.8 37 16.7 38 62 10.3 37.4 E 1943 5.2 28 .88 .66 32 4.6 8.8 28 12.0 48 52 6.2 . . . . . . .. m Average 5.9 29 .91 .71 32.7 4.90 8.20 33 13.7 45.8 54.3 7.5 30.4 g Average for 1941 . . . . . . . . . . 5.7 29 .94 .78 31.0 5.06 8.32 33 10.1 38.4 61.6 5 24.1 g Average for 1942 . . . . . . . . . . . . .. 28 .97 .70 41 .0 4.20 8.02 41 14.8 39.2 60.8 36. Average for 1943 . . . . . . . . . . . . .. 5.1 29 .89 .70 31.6 4.76 8.86 27 9.0 52.6 47.4 .2 18.8 50 50 Mebane 140 1941 4.5 29 .88 .73 26 5.6 9.2 35 7.4 3.7 24.0 1942 5.5 29 .98 .75 36 4.3 8.2 33 8.9 35 65 5.8 37.9 Average 5.0 29 .93 .74 31.0 4.95 8.70 34 8.2 42.5 57.5 4.8 31.0 Rogers Acala 1941 7.0 29 1.13 .89 35 4.1 9.1 37 11.6 40 60 7.0 28.6 1943 5.0 33 1.02 .76 38 4.4 10.0 24 7.5 41 59 4.4 . . . . . . .. Average 6.0 31 1.08 .82 36.5 4.25 9.55 30 9.6 40.5 59.5 5.7 . . . . . . .. Okla. Tri. xCLxCl... 1942 5.0 31 1.03 .80 35 4.3 8.3 37 13.2 47 53 7.0 . . . . . . .. 1943 4.5 28 .81 .62 32 5.4 8.7 19 10.1 36 64 10.1 . . . . . . .. Average 4.8 30 .92 .71 33.5 4.85 8.50 28 11.6 41.5 58.5 8.6 . . . . . . .. _ Ferguson 406 1941 6.0 29 .92 .74 31 5.6 7.1 32 9.0 47 53 4.8 25.0 1942 5.5 26 .98 .73 36 4.2 7.3 43 10.2 41 59 6.0 38.9 Average 5.8 28 .95 .74 33.5 4.90 7.20 38 9.6 44.0 56.0 5.4 32.0 Macha x Acala 1942 5.5 29 1.03 .74 40 4.0 8.4 42 20.6 32 68 14.0 . . . . . . .. 1943 4.3 28 .88 .65 38 4.5 ’ 9.2 25 8.6 43 57 8.7 . . . . . . .. Average 4.9 28 .96 .70 39.0 4.25 8.80 34 14.6 37.5 62.5 11.4 . . . . . . .. LI bIO-IJOO MVH JO LLITVIID BNIINIVEITO is BULLETIN no. s97, TEXAS AGRICULTURAL EXPERIMENT STATION f For the 6 varieties grown for 2 seasons, either 1941 and 1, or 1942 and 1943, at College Station, the grade is higher for ~ later season, with 1 exception where it is the same for bothpseaso (Table 5). There is no difference in average staple between the" seasons, but the mean length is slightly shorter the second seas With 2 exceptions, there are no great differences between the w}, sons for fineness, strength and maturity. There are, however, si nificant differences in the percentages of waste removed from l’ seedcotton. A much higher percentage was removed from Hi-Brl and much lower from Macha in 1942 than in 1941. In all cas there was more waste for the 1941 than the 1942 seasons. For U; 3 varieties grown in 1942 and 1943, both the total waste and t“ percentage removed from the seedcotton were less in 1942 than ' 1943, although there are no great differences in fiber properties. The most striking seasonal differences occurred at Lubbock if Half and Half X Acala (Table 6). In 1942 the cotton was clas 1y; grades lower and 4/32 and 8/32 inches shorter than in 194i‘ and 1943 respectively. The fibers were much finer and less matu in 1942 and there was more than twice as much waste than for t? other 2 seasons. This same variety released approximately 7 p i’ cent of its trash in 1941 in contrast with 38 and 44 percent other seasons. The fiber properties suggest no explanation for thi apparent great difference in cleaning quality of this variety for th/i 3 seasons. * In general, there were improvements in grade with succeedin seasons for both stations. These improvements cannot be assign to changes in the methods of harvesting or cleaning and muse therefore, be attributed to seasonal or varietal differences. f Varieties _ Differences in cottons grown at each station within a given s son must be attributed to differences between varieties since all we a grown and harvested under the same conditions. Varieties differed by as much as 2% grades, 10/32 inch in s ple, 2.5 micrograms per inch for fineness, 27 percent in maturi and 2.1 by Pressley index in strength (Tables 1 and 2). Thus, it " seen that varieties of considerable difference in grade and 0a properties are included among the 84 cottons. ’ Relationship between Waste and Grade In comparing grades and waste certain facts must be kept mind. The classer judges the amount of waste chiefly by the at‘ it occupies in a sample, while it is given herein on the basis ~J CLEANING QUALITY OF RAW COTTON 19 iweight. Thus, waste by the two methods may not always agree. To p, illustrate, waste composed of leaves occupies a relatively large sur- ‘face area, but the same weight of sand, which occupies much less ‘i area, has less effect on grade than does the leaf trash. g. A portion of these cottons was classed by a board of cotton exam- iiners who assigned separate grades to leaf and color, 2 of the 3 p properties (leaf, color and preparation) which are included in grade. That there was a close relationship between waste and the grades of each grade as follows: Leaf Color Grade Waste Grade Waste % % 4 5.2 4.5 5.0 l5 4.3 5 5.6 6 5.6 6 7.2 7 8.5 7 16.5 8 22.0 Correlation coefficients for the composite grade (including leaf, -color and preparation) with waste for the 84 cottons are highly iisignificant. The multiple correlation coeflicient of grade as the de- ' pendent factor with both waste and the fiber properties is 0.73. The ?simple correlation between grade and waste is -o.58. The partial correlation coefficient between grade and waste, independent of the > fiber properties which were measured, is -0.5 5. This is little differ- , ent from the simple coefficient, indicating that of the factors studied, waste accounted for practically all of the differences in grades. Relationship between Waste and Classefs Staple There was found to be little relation between the waste or trash ;~ in the cotton and the classer’s estimate of the staple of the 84 cot- tons. The correlation coefiicient is 0.098, which is not significant. Forty-seven of these-cottons were classed as to staple by a board of cotton examiners (using unpaired samples) before and after the "trash was removed with the Shirley analyzer (Table 7). Thus, the differences in the classer’s staple may be attributed in part to the i, effect of cleaning. Cleaning did not change the staple of I2 of the 47 cottons. Six gained 1/32, and 1 gained 2/32 inch. Twenty lost 1/32 to 2/32 *inch and 8 lost from 3/32 to 5/ 32 inch. The average change was a “loss of slightly more than 1/32 inch. However, in 6o cottons re~ i‘ ported elsewhere (7) the average change in staple due to cleaning p=was less, 2/ 5 of 1/32 inch, which is not significant. ihe leaf and color is shown by comparison of the average waste for 20 BULLETIN NO. 697, TEXAS AGRICULTURAL EXPERIMENT STATION Table 7. Staple length of cotton fibers as given by classers before . after removal of waste by Shirley analyzer ' Staple ———————~——-— Numer- Change ical Fineness Variety by Before grade Waste Mean micro- cleaning cleaning before removed length grams/ 32nd 32nd cleaning % inch inch inch inch Western Early . . . . . . . . . . . . . . . . . 0 30 6.0 5. 7 .84 4.4 7.- Gorhams Lone Star . . . . . . . . . . . . 0 28 6. 5 7.5 .61 3.7 7; Ducona x Lone Star . . . . . . . . . . . . 0 30 5.5 5. 7 .85 5.0 6. Regular Ducona . . . . . . . . . . . . . . . . 0 28 6.0 7.5 .69 3.8 8. Deltapine 14 . . . . . . . . . . . . . . . . . .. 0 28 7.0 11.8 .69 3.9 7. Western Early 4/61 . . . . . . . . . . . . 0 28 5.0 4.3 .68 4.8 6. Macha 5/25 . . . . . . . . . . . . . . . . . .. 0 26 5.5 6.8 .66 4.9 7. Western Early . . . . . . . . . . . . . . . .. 0 28 6.0 10.4 .60 3.7 7. Clark x Missdale 3/50 0 28 5.0 5.5 .68 4.6 7. West. Early x Macha 4/40..... 0 26 5.0 4.7 .61 5.0 7. i. Machax Acala 4/5 . . . . . . . . . . . .. 0 28 4.0 6.3 .56 4.3 7. .. Western Early 5/65 . . . . . . . . . . .. 0 26 5.0 3.3 .67 5.2 6. Meb. 804 x Meb. 140 . . . . . . . . . . . —l 30 6.0 5.4 .79 4.6 7. . (‘lark x Meb. 140 . . . . . . . . . . . . . . —l 29 6.0 4.9 .73 4.9 7. Regular Ducona . . . . . . . . . . . . . . . . -1 29 8.0 9.4 .82 4.4 7. < Suntex . . . . . . . . . . . . . . . . . . . . . . .. ——1 29 6.0 3.9 . 68 4.9 7. Macha 5/40 . . . . . . . . . . . . . . . . . .. —1 29 5.0 5.6 .68 4.2 7. -_ Rogers Texacala . . . . . . . . . . . . . . . —-l 29 5.0 5.1 .66 3.7 7. . Hi-Bred . . . . . . . . . . . . . . . . . . . . . . . —-1 29 5.0 5.9 .75 5.4 6. i Lock. Mebane 140 . . . . . . . . . . . . . . —-1 29 4. 5 3. 7 . 73 5.6 7. Macha . . . . . . . . . . . . . . . . . . . . . . .. +1 29 6.5 6.1 .76 5.5 6. Ferguson 406 . . . . . . . . . . . . . . . . . . +1 29 36.0 4.8 .74 5.6 5. .. Rogers Acala . . . . . . . . . . . . . . . . .. +1 29 7.0 7.0 .89 4.1 7. -~ Oklahoma Triumph . . . . . . . . . . . . +1 29 7.0 8.2 . 72 5.6 6. T West. Early x Macha 2/14 . . . . .. +1 ' 23 5.0 4.4 .72 5.1 Meb. 804 x Meb. 140 . . . . . . . . . . . .+1 29 7.0 8.0 .72 5.3 8. Deltapine 44-51 . . . . . . . . . . . . . . . . —2 32 8.0 9.0 .86 4.7 7. i"; Arkansas B5....~..... . . . . . . . .. —2 26 6.0 7.4 .56 4.6 7. Holtz . . . . . . . . . . . . . . . . . . . . . .. —2 28 5.5 6.8 .61 5.0 7. 7 St.xH.&I-I.xSt.l/28 . . . . . . .. —2 28 5.5 3.4 .69 5.4 7. Ducona x Lone Star . . . . . . . . . . .. —2 30 7.0 6.6 .78 5.2 7. ~‘ H.&H. x Acala . . . . . . . . . . . . . .. -—2 30 7.0 5.9 .72 5.4 7.. H.&H.SA(:8la . . . . . . . . . . . . . .. ——2 28 5.0 6.9 .72 5.5 6.7’ Deltapine . . . . . . . . . . . . . . . . . . . . . —2 31 6.0 5.2 .82 4.5 6. l? Macha x Acala 4/7 . . . . . . . . . . . .. —2 ‘ 28 . 5.0 3.9 .65 4.4 7. ‘.2 Macha x Acala 6/68-98 . . . . . . . .. —2 28 4.0 4.8 .73 . 4.9 7. Western. Early 4/60 . . . . . . . . . . .. ~—2 ‘S 5.0 6.6 .69 5.2 6. Duc x Cl x Duc x Duc 5/63 . . . . . . —2 26 5.0 2.2 .70 5.2 6. l Okla. Tri. x Cl. x Cl. 3/67 . . . . . . . +2 28 4.5 6.5 .62 5.4 7. Roldo Rowden . . . . . . . . . . . . . . . .. —3 29 6.0. 5.2 .65 5.4 7. Rogers Acala . . . . . . . . . . . . . . . . . . -3 33 5.0 4.4 .76 4.4 8. i Western Early . . . . . . . . . . . . . . . . . —4 30 8. 0 8. 7 . 76 4. 4 7. . Oklahoma Triumph . . . . . . . . . . . . . —4 30 6.0 5.8 .63 4.1 7. Western Meb. 140 . . . . . . . . . . . . . —4 28 6.0 4.9 .59 4.9 7. H.&H.xAcalal/7 . . . . . . . . . . .. -—4 32 5.0 4.0 .72 4.7 7. Western Early 4/63 . . . . . . . . . . . . —4 30 4.0 4.4 .68 5.0 7. f Coker’s Wilds 15 . . . . . . . . . . . . . . ——_5 35 7.5 15.5 .83 2.9 8. __‘ Average . . . . . . . . . . . . . . . .. —1.17 28.9 5.78 6.17 .708 4.75 7. i The correlation coeflicient between waste and change in stapl ' of the 47 cottons is 0.40, which is highly significant. In general, i_ appears that the greater the percentage of waste the greater is g change in staple when the waste is removed. Two of the 5 cotto‘ which lost 4/ 32 inch in staple when cleaned, had 8.7 and 4 percei waste —- wastes no greater than for a number of cottons whi were classed either as having no change in staple, or as being lon 9 after cleaning. Correlation between Waste, Grade and Fiber Properties The relationships among grade, waste and fiber properties measured by correlation analysis are given in Table 8. CLEANING QUALITY OF RAW COTTON 21 iTable 8. Correlations between waste, grade and physical properties of cotton fibers y“ Imma- Mean Classer’s Waste turity Fineness length length Strength immaturity . . . . . . . . . . .541 ** A Fineness . . . . . . . . . . .. .302** .516** ». Mean length . . . . . . . .. .222* .323** .527** Classefs length . . . . .. .098 .257* .39l** .664** Strength . . . . . . . . . . . . . .027 .065 .237* .375** .304** 'Gl'8de............... .582** .367**( .016 .2l5* .162 .120 Waste with immaturity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 ** Independent of fineness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .472** Independent of mean length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .509** Independent of fineness and length . . . . . . . . . . . . . . . . . . . . . . . . . .469** Waste with fineness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302** Independent 0t’ immaturity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .031 Independent of length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .224* Independent of length and immaturity . . . . . . . . . . . . . . . . . . . . . . .006 Waste with mean length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222* Independent of fineness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .077 Independent of immaturity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .058 Independent of fineness and immaturity . . . . . . . . . . . . . . . . . . . . . .050 Grade with waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .582** Independent of immaturity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .490** Independent of fineness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .6l6** Independent of length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., . . . . . . .56l** Independent of immaturity and fineness . . . . . . . . . . . . . . . . . . . . . .5l6** Independent of fineness and length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .487** Independent of immaturity and length . . . . . . . . . . . . . . . . . . . . . . .61 9** Independent of fineness, immaturity and length . . . . . . . . . . . . . . .521 ** Length with immaturity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .323** Independent of fineness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .070 Length with fineness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .527** Independent of immaturity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .444** *Significant at 5% level **Significant at 1% level Among the 5 fiber properties, 3 were found to be closely related to waste. These are in order — immaturity, fineness and mean length. Neither the classer’s estimate of length, nor strength show a significant relationship to waste. The correlation coefficient be- tween grade and waste is 0.582. The correlation coefficient of 0.541 between waste and immatu- rity is not significantly changed when made independent of either fineness or length, or of both fineness and length. However, fine- ness was found to be closely associated with waste, but when inde- pendent of immaturity, the coefficient becomes 0.031, indicating that the relationship between waste and fineness was due to the rela- tionship of fineness to immaturity. Fineness, as given in this re- port, is based upon weight of the fiber; therefore, it is possible to I class as equally fine thin-walled coarse fibers and thick-walled fine fibers. Such a possibility emphasizes the importance of including maturity when determining other fiber properties, particularly fine- 11655. 22 BULLETIN NO. 697, TEXAS AGRICULTURAL EXPERIMENT STATION Although the correlation coefficient between waste and length is; statistically significant, removing the effect of fineness, of immatu-j rity, and of both fineness and immaturity, reduces it to 0.077, 0.058} and 0.050, respectively. Thus, it appears that any effect of length‘; on waste is due to the relationship of length to immaturity ani fineness. Length and immaturity have a coefiicient of 0.323, which independent of fineness becomes 0.070, indicating that their rela-} tionship is due to their common relationship with fineness. There: is close relationship between length and fineness, a coefiicient of 0.527, which, independent of immaturity, becomes 0.444. This showsé that irrespective of immaturity, length and fineness are closely re- y, lated. However, length as such had no effect upon the waste. I It appears then, based on these 84 cottons, that a high amount of trash retained by long, fine cottons is not due to the length and i fineness of the fibers but to the relatively high percentage of fibers 7 with thin walls (immature fibers) which occur in long, fine cottons. ' Fiber Drag and Waste Varieties of cotton differ greatly in their resistance to separation 1 of seeds. This resistance is called fiber drag or-inter-seed fiber drag (8). It has been suggested that there might be a relationship be- tween the fiber drag and the amount of waste in cotton and between the drag and certain of the fiber properties. The fiber drag for 43 of these cottons is given in Tables I and 2. The drag ranges from 60 to 253 grams with an average of 157 grams. Twenty-two of the cottons fall below and 21 above this average. Inspection of the data in the tables suggests that there may be a relationship between drag and fineness, but correlation coefficients show that drag is not related to any of the fiber prop- f erties nor to the waste in the cotton. The partial coefiicients range downward from -0.23 between drag and fineness to 0.02 for waste, .; which are not significant. Apparently, resistance which fibers offer to seed separation has j no effect upon the amount of trash found in the cotton. ‘ Plant Height and Waste It is commonly thought that those plants which are tall and have a many branches result in a seedcotton which contains more leaf, stem a and other plant trash than result from shorter, less branching plants. The plant height for 39 of the College Station and 28 of they. Lubbock cottons with corresponding waste are given in Tables 9 and 1o. ’ CLEANING QUALITY OF RAW COTTON College Station 23 The average plant heights and wastes for the 39 College Station cottons for each of the 3 seasons are respectively 27.2 inches and 14.7 percent for 1941, 26.7 inches and 11.9 percent for 1942, and 26.1 inches and 14.6 percent for 1943. For the 3 seasons, the aver- ages are 26.7 inches and 13.6 percent. There is little difference be- tween the averages of plant heights for the 3 seasons. The 1941 Table 9. Plant height and waste of varieties of cotton grown at College Station during 3 seasons Total Waste Waste Waste in Plant waste in removed removed 100 gms. Variety . . . . . . . . . . . . height 100 gms. from from (asclassed) inche seedcotton seedcotton lint grams grams % % 1941 Gorhams Lone Star . . . . . . . . . . . .. 21.2 19.3 42.0 58.0 11.2 Western Early . . . . . . . . . . . . . . . . . 25.2 14.7 40.8 59.2 8.7 Macha . . . . . . . . . . . . . . . . . . . . . . .. 25.2 17.6 37.5 62.5 11.0 H.&H.xAcala . . . . . . . . . . . . . . .. 25.5 11.2 47.3 52.7 5.9 Deltapine 44-51 . . . . . . . . . . . . . . .. 25.5 14.3 37.1 62.9 9.0 DuconaxLone Star . . . . . . . . . . . .. 27.0 11.4 42.1 57.9 6.6 Meb. 804xMeb. 140 . . . . . . . . . .. 28.9 13.4 40.3 59.7 8.0 Mebane 804-50 . . . . . . . . . . . . . . . . 28.9 13.9 44.6 55.4 7.7 Rogers Texacala . . . . . . . . . . . . . . . . 29. 2 12. 4 36.3 63 . 7 7. 9 Oklahoma Triumph . . . . . . . . . . . . . 29. 2 14 . 5 43.4 56. 6 8. 2 Hi-Bred . . . . . . . . . . . . . . . . . . . . . .. 29.2 18.5 54.6 45.4 8.4 Regular Ducona . . . . . . . . . . . . . . .. 31.1 15.1 37.7 62.3 9.4 Average . . . . . . . . . . . . . . . . .. 27.18 14.69 41 98 58 02 8.50 1942 Oklahoma Triumph . . . . . . . . . . . . . 24.0 12.5 39.2 60.8 7.6 Macha . . . . . . . . . . . . . . . . . . . . . . .. 24.3 16.3 23.3 76.7 12.5 Deltapine 14 . . . . . . . . . . . . . . . . . .. 24.5 12.5 44.0 56.0 7.0 Greer 5-3 . . . . . . . . . . . . . . . . . . . . .. 24.9 8.4 16.7 83.3 7.0 Western Early . . . . . . . . . . . . . . . .. 26.1 16.2 57.4 42.6 6.9 Roldo Rowden . . . . . . . . . . . . . . . .. 26.1 10.0 31._0 69.0 6.9 Western Meb. 140 . . . . . . . . . . . . . . 26.1 14.3 25.9 74.1 10.6 Gorhams Lone Star . . . . . . . . . . . .. 26.3 8.4 28:6 71 .4 6.0 Holtz . . . . . . . . . . . . . . . . . . . . . . . . .. 26.3 8.8 28.4 71.6 6.3 Stoneville 2B . . . . . . . . . . . . . . . . .. 27.0 15.0 54.0 46.0 6.9 Hi-Bred . . . . . . . . . . . . . . . . . . . . . .. 27.4 14.3 67.1 32.9 4.7 _ Rogers Texacala . . . . . . . . . . . . . . . . 28.0 10.6 29.2 70 8 7.5 Suntex . . . . . . . . . . . . . . . . . . . . . . .. 29.0 9.9 22.2 77.8 7.7 Mebane 804-50 . . . . . . . . . . . . . . . . . 30.1 10.5 42.9 57.1 6.0 Regular Ducona . . . . . . . . . . . . . . . . 30.9 11.3 27.4 72.6 8.2 Average . . . . . . . . . . . . . . . .. 26 73 11.93 35.82 64 18 7.45 1943 Gorhams Lone Star . . . . . . . . . . . .. 19.8 15.0 50.0 50.0 7.5 Holtz . . . . . . . . . . . . . . . . . . . . . . . . .. 25.4 13.3 48.9 51.1 6.8 ArkansasBS . . . . . . . . . . . . . . . . . .. 25.8 13.8 46.4" -53.6 7.4 Suntex . . . . . . . . . . . . . . . . . . . . . . .. 26.1 11.2 65.2 34.8 3.9 Deltapine 14 . . . . . . . . . . . . . . . . . .. 26.1 17.5 32.6 67.4 11.8 Rogers Texacala . . . . . . . . . . . . . . . . 26 . 3 9. 9 48 . 5 51 . 5 5. 1 Roldo Rowden . . . . . . . . . . . . . . . . . . 26.3 l0. 9 52.3 47.7 5.2 Western Early . . . . . . . . . . . . . . . . . . 26.3 16.3 36.2 63.8 10.4 Regular Ducona . . . . . . . . . . . . . . . . 26.5 12.5 40.0 60.0 7.5 Oklahoma Triumph . . . . . . . . . . . . . 28. 0 11 . 8 50 . 8 49. 2 5.8 Western Meb. 140 . . . . . . . . . . . . .. 28.1 11.6 57.8 42.2 4.9 Coker’s Wilda 15 . . . . . . . . . . . . . . . 28.4 29.7 47.8 52.2 15.5 Average . . . . . . . . . . . . . . . . . 26 09 14 56 48.04 51.96 7.65 Average for 39 cottons. . . . . . . . 26.67 13. 56 41 47 58. 53 7.84 I cotton the coeflicient is -0.01 3, neither of which is significant. There} 24 BULLETIN NO. 697, ‘TEXAS AGRICULTURAL EXPERIMENT STATION and I943 cottons contain approximately the same percentage wast} 14.7 from the tallest plants (27; inches) and 14.6 from the sho est plants (26.1 inches). Although the I942 plants were slightli taller than the I943 plants, the cotton contains much less waste. For the 39 College Station cottons the correlation coeflicient tween plant height and waste in the seedcotton is 0.074, and a tween height of plant and percentage waste removed from the seeder apparently was little relationship between the height of the plants and the waste from the College Station cottons. Lubbock _ For the Lubbock cottons the averages of the height and waste for. 1 I cottons in 1941 are 2 3.9 inches and 9.7 percent ; for 14 cottons’ Table 10. Plant height and waste of varieties of cotton grown at Lubbock during 3 seasons Total Wate Waste Waste in Plant waste in removed removed 100 gms. Variety height 100 gms. from from (asclassed) inches seedcotton seedcotton lint grams grams % % 1941 Dpcona x Lone Star . . . . . . . . . . . . . 20.0 9.9 42.4 57.6 5.7 Hl-Bred . . . . . . . . . . . . . . . . . . . . . .. 20.8 9.5 37.9 62.1 5.9 ClarkxMeb. 140 . . . . . . . . . . . . . .. 21.4 8.9 44.9 55.1 4.9 Meb.804XMeb.140 . . . . . . . . . .. 23.5 10.1 46.5 53.5 5.4 Macha . . . . . . . . . . . . . . . . . . . . . . .. 23.5 12.4 50.8 49.2 6.1 Lock. Mebane 140 . . . . . . . . . . . . . . 24.0 7.4 50.0 50.0 3.7 H.&H.xAcala . . . . . . . . . . . . . . .. 24.1 7.4 6.8 93.2 6.9 Ferguson 406 . . . . . . . . . . . . . . . . . . 25.0 9.0 46.7 53.3 4.8 Western Early . . . . . . . . . . . . . . . . . . 25. 5 11.4 50.0 50.0 5. 7 Deltapine . . . . . . . . . . . . . . . . . . . . . . 26.7 9.6 45.8 54.2 5.2 Rogers Acala . . . . . . . . . . . . . . . . . .. 28.6 11.6 39.7 60.3 7.0 Average . . . . . . ...._ . . . . . . . 23.92 9.74 41 95 58 05 5.57 1942 Okla. TrLXCLXCI . . . . . . . . . . . .. 23.8 13.2 47.0 53.0 7.0 Macha (Jones) . . . . . . . . . . . . . . . . . 33.3 11.7 39.3 60. 7 7. 1 H.&H.xAcala . . . . . . . . . . . . . . .. 33.6 16.1 38.5 61.5 9.9 Duc.xCl.xDuc . . . . . . . . . . . . . . .. 34.4 10.4 44.2 55.8 5.8 Hi-Bred . . . . . . . . . . . . . . . . . . . . . .. 34.7 10.8 30.6 69.4 7.5 . Sh! H.&H.xSt.117. . . . . . . . .. 36.9 15.9 40.3 59.7 9.5 ' Western Early . . . . . . . . . . . . . . . .. 37.1 16.2 42.0 58.0 9.4 Macha (Macha) . . . . . . . . . . . . . . .. 37.4 16.7 38.3 61.7 10.3 % Deltapine . . . . . . . . . . . . . . . . . . . . . . 37.6 14.0 47.1 52.9 7.4 . Lock. Mebane 140 . . . . . . . . . . . . .. 37.9 8.9 34.8 65.2 5.8 Sh! H.&H.XSL111 . . . . . . . . .. 38.1 14.3 43.4 56.6 8.1 ; Ferguson 406 . . . . . . . . . . . . . . . . . . 38.9 10.2 41.2 58.8 6.0 i Macha x Acala . . . . . . . . . . . . . . . . . 44.5 20.6 32.0 68.0 14.0 5 Sh.xH.&H.x Shafter . . . . . . . .. 46.3 11.8 35.6 64.4 7.6 5' Average . . . . . . . . . . . . . . . . . 36. 75 13 63 39 59 60 41 8.24 '1 1943 Hi-Bred . . . . . . . . . . . . . . . . . . . . . .. 17.2 6.2 58.1 41.9 2.6 Deltapine 14 . . . . . . . . . . . . . . . . . . . 20.3 10.7 65.4 34.6 3.7 Coker’s Wilds 15 . . . . . . . . . . . . . . . 21.2 11 3 53.1 46.9 5.3 Average . . . . . . . . . . . . . . . .. 19.57 9.40 58.87 41.13 3.86 Average for 28 cottons . . . . . . . . . . . 29.87 11 . 65 42.58 57.41 6. 72 CLEANING QUALITY OF RAW COTTON 25 in 1942, 36.8 inches and 13.6 percent; and for 3 varieties in 1943 ‘iwere 19.6 inches and 9.4 percent. For the 28 Lubbock cottons the averages of height and waste are 29.9 inches and 11.65 percent. The greatest waste occurs in 1942 when the plants were the high- p est as a result of heavy applications of fertilizer and water. Har- vesting in 1942 was done after frost when the branches and leaves iwere dry and brittle. There were approximately equal wastes for 1941 and 1943 when the plant heights differ more than 4 inches. i In contrast with the 39 College Station cottons, the correlation coefficient between the height and the waste in the seedcotton for the 28 Lubbock cottons is 0.629, which is highly significant (at the 1 percent level); and the coefficient between plant height and the ' percentage of waste removed from the seedcotton is —0.4o4; which is .3 significant (at the 5 percent level). These results indicate that more data are needed before it can be definitely stated that there is a close relationship between the height of the plant and the amount of trash harvested. It is possi- i’ ble that the number and length of the branches and the brittleness j of the stems and leaves may have a greater effect on the amount of E i E E t l l i‘ l E i E. 7 trash harvested and the percentage removed than does the height E of theiplant. Rainfall and Waste The rainfall for each of the 3 seasons at each of the 2 stations is ‘ given in Table 11. Table 11. Rainfall at College Station and Lubbock, 1941-43 College Station Lubbock 1941 1942 1943 1941 1942 1943 Inches Inches Inches Inches Inches Inches ‘ January . . . . . . . . . . . . . 1.55 .56 2. 98 .55 .04 .04 February . . . . . . . . . . .. 3.64 1.15 .18 .61 .18 .02 _ March . . . . . . . . . . . . .. 6.63 1.27 2.17 3.56 .51 .25 April . . . . . . . . . . . . . . .. 7.91 7.79 .67 2.23 3.25 .53 May . . . . . . . . . . . . . . .. 3.06 3.91 7.04 12.69 .35 2.71 June . . . . . . . . . . . . . . .. 6.39 5.36 1.76 4.13 1.74 2.37 July . . . . . . . . . . . . . . .. 5.49 2.58 5.66 3.68 2.58 3.17 August . . . . . . . . . . . . .. 2.76 3.05 .50 1.85 4.97 0 September . . . . . . . . . .. 2.67 6.17 3.14 4.47 7.61 1.16 October . . . . . . . . . . . .. 6. 75 2.05 .77 5.89 3.39 .10 November . . . . . . . . . .. 1.61 5.18 2.44 .17 .01 .62 December . . . . . . . . . .. 2.12 2.32 3.19 72 2.70 1.87 Total . . . . . . . .. 44.58 41.39 30.50 40.55 27.33 12.84 Average for 57 years 38. 82 inches Average for 35 years 19. 21 inches _ June, July and August 14.64 10.99 7.92 July. August and I September . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 15. 16 4.33 26 BULLETIN NO. 697, TEXAS AGRICULTURAL EXPERIMENT STATION College Station Both the annual rainfall and that during the growing season at College Station were much greater in 1941 than in 1942 or 1943 and greater in 1942 than in 1943. In 5 of the 6 varieties grown 3i seasons, the greatest waste was found in 1941 when the rainfall " was heaviest. The waste was also greater in 1941 than in 1942 for the 3 varieties grown both in 1941 and 1942. However, in 4 of the _ l 6 varieties grown 3 seasons the waste was greater for 1943 than I for 1942, although the rainfall was greater in 1942. There does i not appear to be a close relationship between total rainfall and the ‘ amount of waste in the College Station cotton. Lubbock There were wide differences among the 3 seasons in the annual rainfall at Lubbock, 2 of which were considerably above and I be- low the 35-year average. The average total waste and the total rainfall for each season are as follows: 9.7 grams and 40.6 inches for 1941, 13.6 grams and 27.3 inches for 1942, and 8.9 grams and 12.8 inches for 1943. The greatest waste occurred in 1942 when the annual rainfall was less than in 1941, but more than in 1943. However, the rainfall during the growing season was higher in 1942 than in either 1941 or 1943 i and, in addition, there were heavy applications of fertilizer and irrigation water. The plants were unusually rank and brittle, which l probably accounts in part for the greater total waste in the cotton for I the 1942 season. In 1942, the cottons had a higher percentage immaturity than ; in either of the other seasons, which probably accounts for the greater waste. When rainfall or irrigation is heavy, immaturity is _ greater; therefore, waste is greater. Etfect of Method of Harvesting on Fiber Properties The question is frequently asked if there are any differences be- ' tween the properties of the fibers of cotton harvested by different methods. It has always been assumed that there were none To determine if the assumption is valid, 3 of the varieties, which were harvested by picking, snapping, and stripping, were analyzed as to fiber properties for each of the 3 methods of harvesting. The results are given in Table 12. As expected, there are differences in grade. In each variety the grade is higher for the picked than for the stripped, and the picked higher than for the snapped in every case but one, where the ¢W-._.,,._..... Table 12. Physical properties of fibers of 3 varieties of cotton harvested by 3 methods at College Station in 1942 Mean length Waste removed from 100 grams _ Method Numer- Staple -—-———-—-———-———— Length Fineness Variety of ieal 32nd Coef. of at 25% micro- Strength Imma- From From harvesting grade inch vari- point grams index turity seed- From Total seed- From Inches ability inch per inch % cotton lint grams cotton lint _ % grams grams % % Picked 5.0 24 .57 33 .75 5.6 9.1 36 . . . . . . .. 5.3 . . . . . . . . . . . . . . . . . . . . . . .. Hi-Bred Snapped 6.0 26 .52 36 .71 6.0 8.9 40 . . . . . . _. 11.1 . . . . . . . . . . . . . . . . . . . . . . .. Stripped 5.5 26 .54 34 .72 6.3 8.9 40 9.6 4.7 14 3 67 33 Picked 5.5 30 .76 34 1.03 4.2 9.7' 36 . . . . . . .. 5.3 . . . . . . . . . . . . . . . . . . . . . . .. DLP l4 Snapped 7.0 30 .76 33 1.02 4.5 9.4 37 . . . . . . .. 8.0 . . . . . . . . . . . . . . . . . . . . . . .. Stripped 6.0 30 .76 34 .99 4.4 9.5 36 5.5 7.0 12 5 44 56 Picked 6.0 30 .77 34 1.00 4.4 9.1 38 . . . . . . .. 4.6 . . . . . . . . . . . . . . . . . . . . . . .. Western Early . . . . . . Snapped 6.0 29 .69 35 .92 4.4 9.3 41 . . . . . . . . 7.0 . . . . . . . . . . . . . . . . . . . . . . . . Stripped 7.0 30 .73 32 .94 4.4 9.6 36 9.3 6.9 16 2 57 43 LZ NOLLOO MVH JO LJLITVIID DNINVIITO 28 BULLETIN NO. 697, TEXAS AGRICULTURAL EXPERIMENT STATION snapped and picked are the same grade. There are no signifi -, differences in the fiber properties. It is concluded, therefore, t if any selection of cotton due to the method of harvesting does n materially affect the fiber properties. i Summary and Conclusions The relationship between the properties of the cotton fiber . the cleaning quality of cotton has been studied in 84 cottons, wh' were grown during 3 seasons in 2 regions of Texas. In general, for the 3 seasons the cottons grown at College S tion were lower in grade, of approximately equal length, slighii coarser, stronger,“ more immature, and contained more trash t the cottons grown at Lubbock the same seasons. There were wide differences in fiber properties of the cotto, grown at ‘each station, which are attributed to season and to varied Although there is no apparent close relationship between the amo of rainfall and fiber properties, rainfall plus heavy irrigation fertilizer at Lubbock in 1942 resulted in a larger plant, more and more immature fibers. It has been observed that seasons Y heavy rainfall produce a higher percentage of immature fibersj Of the fiber properties studied, only 3 — immaturity, leng and fineness — appear to be closely associated with the clean' quality of the cotton. The longer, the finer, and the less matur cotton the greater is the amount of trash retained by the u‘ However, statistical analyses show that the effects of length I fineness are due to their close relationship with immaturity. Of ' 3 properties, only immaturity, as such, affects the waste. It app that the difliculty of removing trash from long, fine cottons is due to the length and fineness of the fibers but to the relatively hid percentage of thin-walled or immature fibers which occur in l0,’ fine cottons. lThose varietal and seasonal factors which produce l0 fine fibers may also produce immature fibers which retain w’ _ Heavy rainfall, heavy applications of fertilizer and irrigation p i, ably acted in 2 ways in increasing the waste: first, the plants ?” came rank with a relatively large number of leaves and bran . and a large amount of trash was harvested; second, there higher percentage of immature fibers due to the large amount? water. When there is heavy rainfall or irrigation during the of the formation of the secondary layers of the fibers, relativ‘ large numbers are observed to be thin-walled or immature. there were more immature fibers, more trash was harvested, more trash was retained by the immature fibers than in seasons- less rainfall. l CLEANING QUALITY OF RAW COTTON 29 This study raises the question whether there are factors which have greater influence than fiber properties on the cleaning quality of cotton. It seems quite probable that the nature of the trash may have greater influence on the quantity clinging t0 the fiber after cleaning than do the properties of thefiber. The shape, size, num- ber and thickness of leaves, the pubescence of leaves and stems, number and size of branches, nature of bracts and-burs, and other physical properties of the plant may have greater effect on the ex- t tent to which trash and fibers adhere than do the length, fineness, strength or other properties of the fiber. This possibility should be investigated. Acknowledgments Grateful acknowledgment is made of the assistance of H. P. Smith of the Department of Agricultural Engineering; D. T. Killough of the Department of Agronomy; and D. L. Jones, superintendent of the Lubbock station, for furnishing the cottons used in the study. The data on height of plants, fiber drag, and waste removed through those processes including ginning, were furnished by H. P. Smith. Thanks are due J. M. Ward 0f the Department of Agri- cultural Economics and Sociology for classing the cottons, and R. E. Patterson, assistant director of the Texas Agricultural Experi- ment Station, for helpful suggestions in the statistical interpreta- tion of the data. Bibliography 1. Smith, H. P., Killough, D. T., Jones, D. L., Byrom, M. H., 1939. Me- chanical harvesting of cotton as affected by varietal characteristics and other factors. Tex. Agr. Expt. Sta. Bul. N0. 58o. 2. A.S.T.M. Committee D-13, 1946. Standards on textile materials. 3. Grimes, Mary Anna, 1942. Measuring fiber fineness. Textile Research XIII, 1, November 1942, pp. 12-18. 4. Pressley, E. H., 1942. A cotton fiber strength tester. A.S.T.M. Bul. No. 118, pp. 13-17, Oct. 1942. s. Grimes, Mary Anna, 1944. Two methods of determining the maturity of cotton fibers. Tex. Agr. Expt. Sta. Progress Report No. 915. 6. Pfeiffenberger, George W., 1944. The Shirley Analyzer. Textile Research Vol. XIV, No. 2, Feb. 1944, pp. 50-54. 7. Grimes, Mary Anna, 1945. The effect of foreign matter on the grade, staple and price of cotton. Tex. Agr. Expt. Sta. Progress Report No. 954. 8. Smith, H. P., Killough, D. T., Jones, D. L., 1946. Factors affecting the per- formance of mechanical cotton harvesters (stripper type), extractors and cleaners. Tex. Agr. Expt. Sta. Bul. No. 686. 9. Smith, H. P., Rouse, Joseph T., Killough, D. T., Jones, D. L., 1946. Com- parison of different methods of harvesting cotton. Tex. Agr. Expt. Sta. Bul. No. 683.