\ TEXAS AGRICULTURAL EXPERIMENT STATIQN R. D. LEWIS. Director. College Station, Texas pa». 7A,? $3..“ .1 f?£,,‘,, ‘\I~* >4 v4 >4; Lé-siil z? -v u; ‘.:L n1 YYH b; ‘J-J 4 -_~'\ Fr €~ 15;" 53g The C|eaning of Mechanicauy Harvested Cotton >1? i $3 F AR‘? ‘ » 3" Y. ' " { ‘Efjkifi! (3 ,1 i» 31-. w é i “ I ‘A ‘n’ L}? V" ‘~ w» w‘ * =~ ~ ' H. P. SMITH, D. L. JONES and H. F. MILLER, JR. i?‘ The TEXAS AGRICULTURAL AND MECHANICAL COLLEGE SYSTE ‘E cuss GILCHRIST, Chancellor [Blank Page in Original Bulletin] Preface For many years cotton growers in the High Plains area have found that cotton harvested late in the season contained an excessive amount of foreign matter, and that the quality of the cotton was much lower than that of cotton harvested early in the season. This bulletin gives the results of a study conducted at Lubbock and College Station to determine the amounts of different kinds of foreign matter removed in the extracting, cleaning, ginning and spinning of cotton mechanically stripped and mechanically picked at early, mid-season and late dates. Several varieties of cotton with different fiber qualities were harvested with strippers, designated as Nos. 15 and 16 machines, and with a spindle- type picker. At Lubbock, the stems in late-harvested cotton increased 175 percent and the dirt and sand increased 209 percent over early-harvested cotton when the No. 15 stripper was used. Where the cotton stripper was equipped with a tractor-mounted field extractor, termed the No. 16 machine, the total foreign matter removed averaged less than half the amount removed from cotton stripped with the No. 15 machine without an extractor. The cleaner removed an average of approximately 7 percent foreign matter from_ machine-stripped cotton and from machine-p-icked cotton that was poorly defoliated. At Lubbock, in late-harvested cotton, the dirt and sand removed by the cleaner increased 166 percent over early-harvested cotton stripped with the No. 15 machine. Higher percentages of foreign matter were removed by the cleaner from the normal boll than from the stormproof types of cotton. The average total foreign matter removed in extracting, cleaning and ginning of cottons machine-stripped at Lubbock at early, mid-season and late harvest dates was 28.2, 31.1 and 34.6 percent, respectively. At College Station, the total was 46.5, 42.9 and 41.1 percent, respectively, of the original sample. When the No. 16 machine was used at Lubbock, the total was 15.6, 19.2 and 17.5 percent, respectively. At both Lubbock and College Station, the strength of 22 yarn in all but one of the varieties became weaker as the harvest was made later. The yarn from the stromproof strain, CA 89A, became stronger as the harvest was delayed. CONTENTS U Page Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Equipment Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 Method of Separating the Foreign Matter . . . . . . . . . . . . . . . . . . . . . . . . .. 9 Varieties Used . . . . . . . . . . . . . . . . . . . . . . .._. . . . . . . . . . . . . . . . . . . . . . . . . .. 11 Dates of Harvest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11 i: Defoliation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 ‘ Foreign Matter Removed from Machine-stripped Cotton . . . . . . . . . . . .. l2 Foreign Matter Removed by the Extractor . . . . . . . . . . . . . . . . . . . .. 14 Foreign Matter Removed by the Cleaner . . . . . . . . . . . . . . . . . . . . . .. Foreign Matter Removed by Ginning . . . . . . . . . . . . . . . . . . . . . . . . . .. 23A Total Pounds of Foreign Matter Removed in Extracting, Cleaning f, and Ginning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27“}i Foreign Matter Removed in Spinning Tests . . . . . . . . . . . . . . . . . . .. 31 n: Grade of Machine-stripped Cotton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35b; Staple Length of Machine-stripped Cotton . . . . . . . . . . . . . . . . . . . . . . . . .. 36— Strength of 22 Yarn from Machine-stripped Cotton . . . . . . . . . . . . . . . .. 361 Appearance of Yarn from Machine-stripped Cotton . . . . . . . . . . . . . . . . .. 38~ Neps in the Card Web 0-f Machine-stripped Cotton . . . . . . . . . . . . . . . . .. Maturity of Fiber in Machine-stripped Cotton . . . . . . . . . . . . . . . . . . . . .. 39_ Foreign Matter Removed from Machine-picked Cotton . . . . . . . . . . . . . .. Foreign Matter Removed by the Cleaner . . . . . . . . . . . . . . . . . . . . . .. 4i Foreign Matter Removed by Ginning . . . . . . . . . . . . . . . . . . . . . . . . . .. Foreign Matter Removed in Spinning Tests . . . . . . . . . . . . . . . . . . . .. Grade of _Machine-picked_ Cotton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Appearance of 22 Yarn from Machine-picked Cotton . . . . . . . . . . . . . . . . . 43$ Staple Length of Machine-picked Cotton . . . . . . . . . . . . . . . . . . . . . . . . . . .. Neps in Card Web and Maturity of Fiber in Machine-picked Cotton . . . Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. - M34-350-3500-L1; ’ BULLETIN 720 MARCH 1950 The Cleaning of Mechanically Harvested Cotton H. P. SMITH, D. L. JONES and H. F. MILLER, JR.* HE cleaning of mechanically harvested cotton is one of the most important problems confronting the cotton farmer and the ginner. More trash or foreign matter is collected with the ~ cotton by the mechanical stripper than by the mechanical » picker. The stripper removes all bolls. Insect and frost-damaged , immature bolls are removed along with the Well-open fully- . matured bolls. Stripped cotton, therefore, must first be separated from the p. burs by the extractor-cleaner equipment. It is then subjected to . further cleaning before entering the gin roll box. The more com- pletely the various kinds of trash, dirt and sand are removed the higher will be the quality of the cotton, if a good job of , ginning is done. Most machine-picked cotton shouldbe dried to remove excess moisture before cleaning begins. As machine-picked cotton does ' not contain a large quantity o-f burs, most of the trash will usually be parts of leaves, bracts and grass stems. After drying, ~ the cotton is passed through the cleaning equipment to the gin roll box. The amount of different kinds of foreign matter removed in the cleaning process, for both machine-stripped and machine-picked cotton of different varieties harvested at different dates, is of considerable interest to the ginner and the farmer. The data reported in this bulletin show the average percent- ages of different kinds of trash and foreign matter removed from machine-stripped and machine-picked cotton harvested at College Station and at Lubbock early in the season, at mid-sea- son and late in the season. Varieties of cotton having different fiber characteristics were planted at each location. *Respectively, professor, Department of Agricultural Engineering, Col- lege Station, Texas; superintendent, Substation No. 8, Lubbock, Texas; and assistant professor, Department of Agricultural Engineering, College Station, Texas. Figure. 1. The N0. 15 stripper harvesting cotton at Lubbock. This machine was not equipped with a tractor-mounted field extractor. Figure 2. The No. 1.6 stripper was equipped with a tractor- mounted field extractor. THE CLEANING OF MECHANICALLY HARVESTED COTTON 7 EQUIPMENT USED A regular and commonly used two-row tractor-mounted com- mercial cotton stripper was used to harvest the samples of stripped cotton at both College Station and Lubbock. This ma- chine Was not equipped with a field extractor. It is known to the trade as the No. 15 cotton stripper (Figure 1). In one of at the series of tests, the No. 15 stripper Was modified and a field Figure 3. Cotton picking machine ‘harvesting cotton at College Sta- tion. The plants were poorly defoliated. 8 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 4. Stationary bur extractor used in processing samples of machine-stripped cotton. Notice the burs falling out under the machine and the cotton dropping from the elevator. Figure 5. Cleaner used to clean samples of ma- chine-stripped and picked cotton. The housing was opened and the remaining material removed with an air jet after A c" __ processing each sample. i THE CLEANING OF MECHANICALLY HARVESTED COTTON 9 extractor mounted on the rear of the tractor. When the stripper was used in combination with the mounted extractor the ma- chine was termed a No. 16 machine (Figure 2). The machine- picked samples were harvested with a commercial one-row tractor-mounted cotton picker (Figure 3). The machine-stripped cotton at both College Station and Lub- bock was extracted on the Texas Station Bur Extractor (Fig- ure 4). This machine has been described in Texas Station Bul- letin 511. The Texas Station Vertical Cleaner, also described in Texas Station Bulletin 511, was used to clean all samples of machine- stripped cotton after the burs had been extracted (Figure 5). The machine-picked samples were cleaned on the same machine. All the samples were ginned on a laboratory 20-saw plain- breasted gin. METHOD OF SEPARATING THE FOREIGN MATTER The following procedure was used in separating the foreign matter into the different classifications: After extracting the burs from the stripped cotton, the stems, sticks and other bulky foreign matter were picked out of the remaining trash by hand (Figure 6). The remaining mass of burs, trash and dirt were screened over a 1/4-inch hardware cloth screen (Figure 7). The material that remained on the Figure 6. Slepaaration of the stems from the burs was done by an . 10 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION screen was classed as burs. The material passing through the 14-inch hardware cloth was sifted over a 50-inch mesh screen (Figure 8). The material remaining on the screen was classed ‘ as fine trash and the material that passed through was classed e as dirt and sand (Figure 9). The different kinds 0f trash were weighed and the difference between the sum of the total trash and the original sample of foreign matter was termed invisible loss. ; The extracted seed co-tton was passed through the cleaner. All foreign matter was carefully collected by cleaning the cleaner l with a jet of air and by sweeping the floor around the cleaner. The foreign matter collected was separated into the different l classes inthe same manner as the extractor trash. Figure 7. The fine trash, dirt and Figure 8. Dirt and sand were sep- l sand were separated arated from the _ fine from the burs by sifting trash by sifting with a < with a 14-inch mesh 50-mesh screen. screen. Figure 9. Dirt and sand were col- lected in a pan attached to the screen. THE CLEANING OF MECHANICALLY HARVESTED COTTON 11 After each sample was ginned, the gin was cleaned and the dirt and trash collected from the floor. This trash was separated into two classes: motes and trash, and dirt and sand. The waste removed by the pickers and cards in preparing the fiber for spinning was collected, weighed and the percentage calculated. In all cases, the percentages of trash removed in each process was calculated against the weight of the sample at the begin- ning of that particular process. For example, the percentage of burs, stems, fine trash, dirt and sand removed by the extrac- tor was calculated against the field harvest weight of the sam- ple. The weight of the extracted and uncleaned seed cotton was the base for the cleaner calculations. Likewise, the Weight of the cleaned seed cotton was the base for the ginning waste. The weight of the lint sample sent to the spinning laboratory was the base for calculating the percentage of picker and card waste. VARIETIES USED Four varieties with wide differences in fiber characteristics were selected for the study. These were Deltapine 14, Mebane 140, Stoneville 2B and CA 122; the latter is a stormproof strain developed at Lubbock. Several other varieties having suitable stripping qualities were included in the study at Lubbock. DATES OF HARVEST Previous studies and observations in the High Plains area around Lubbock showed that the amount of foreign matter col- lected by mechanical strippers increased as harvest was delayed. Therefore, the cotton in the tests was harvested at approxi- mately monthly intervals. The first harvest was classed as early, the second as mid-season and the third as late. The actual dates of harvest, as shown in Table 1, were influenced by the ma- turity of the cotton and the date of the first killing freeze at Lubbock. At College Station, the early date was influenced by wet ground and the rapidity of defoliation after the applica- tion of a defoliant. Only two dates of harvest were made at Lubbock in 1946 because of a late killing freeze. DEFOLIATION Defoliant chemicals were applied to the cotton at College Station in late August or early September, depending on the maturity of the cotton and the ability to get into the fields with tractors. Low rainfall in 1946 caused the plants to become inactiyeggand dust defoliants gave poor results. There was a 9-inch rain on August 26, 1947. This delayed the application BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Table 1. Date-s of harvest at College Station and Lubbock Time College Station Lubbock of harvest 1946 1947 1948 1946 1947 1948 Early . . . . . . . . . . . . . . . Sept. 20 Sept. 23 Sept. 8 . . . . . . . . . . Nov. 5 Oct. 10 Mid-season . . . . . . . . . . Oct. 8 Oct. 20 Oct. 1 Dec. 2 Nov. 26 Nov. l1 Late . . . . . . . . . . . . . . . . Oct. 28 Nov. 24 Nov. 1 Dec. 23 Dec. 29 Dec. 3 of defoliants. The old leaves shed from the plant after the de- foliant was applied, but the heavy rainfall caused the plant to ; revive. New growth was so rapid that full foliage conditions Were encountered when the first harvest was made. Additional I applications of defoliant were not effective until the late har- a vest. The fall of 1948 was dry and neither dust nor spray de- , foliants was very effective. a a At Lubbock, defoliants Were applied before the first killing a freeze in an effort to reduce leaf trash in the stripped cotton. a Most of the leaves shed but perfect defoliation was not obtained due to drouth conditions. FOREIGN MATTER REMOVED FROM MACHINE-STRIPPED . COTTON Foreign matter in the machine-stripped cotton was removed in four separate operations consisting of the extracting, clean- g ing, ginning and spinning processes. As the cotton Was stripped With two types of machines, the results are discussed under the headings of the No. 15 machine at College Station and the Nos. 15 and 16 machines at Lubbock. It should be kept in mind ‘scalvvvvv " _ _ Figure 10. A grill-like bottom for the conveyor and perforations in the bottom of the cross-auger housing eliminate large amounts of fine trash, dirt and sand, and some bur sections. i l i i a i i i i 3 i 5 a i 2% l l THE CLEANING OF MECHANICALLY HARVESTED COTTON 13 Foreign matter, consisting of leaes and stems removed by the screen or grill on. the bottom of the conveyor. A total of 7.4 pounds was removed in 425 feet of row. Figur 11. that a large amount of foreign matter is separated from the seed cotton by the stripper itself as the cotton is conveyed from the stripping units to the trailer. Figure 1O shows for- eign matter falling through the bottoms of the co-nveyer unit and also through perforations in the cross auger housing. Fig- ure 11 shows 7.4 pounds of foreign matter collected from under the conveyer in 425 feet of row. As the cotton harvested with the No. 16 machine passed through an extractor before being conveyed to the trailer, larger quantities of foreign matter were removed in the field with this machine than with the No. 15 machine, which was not equipped with an extractor. Figure 12 shows a comparison of the trash content of cotton harvested with the two machines at Lubbock. Left—-cotton harvested by No. 16 machine which was equipped With extractor. Right——cotton harvested by the No. 15 machine. Figure 12. 14 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Table 2. Average percentages of different kinds of foreign matter removed extractor from varieties of cotton machine-stripped with N0. 15 ma ’ early, mid-season and late harvests at College Station, 1946-48 Variety Seed cotton Fine Dirt and Invisible i (uncleaned) Burs _ Stems trash sand loss Early harvest Deltapine 14 . . . . . . . . . . . . . .. 63.5 31.4 1.1 3.0 .8 .2 Stoneville 2B . . . . . . . . . . . . . .. 63.5 29.0" .6 5.5 .8 .6 ‘ Mebane 140 . . . . . . . . . . . . . .. 62.4 29.5 1.3 5.6 .8 .4 CA 122 . . . . . . . . . . . . . . . . . . .. 64.4 31.8 1.0 1.3 1.0 .5 CA89A . . . . . . . . . . . . . . . . . .. 49.4 27.5‘ 2.5 19.8 .6 .2 Average . . . . . . . . . . . . . . . . . .. 60.6 29.9 1.3 7.0 0.8 0.4 Mid-season harvest Deltapine 14 . . . . . . . . . . . . . .. 63.9 29.8 1.4 3.3 1.4 .2 Stoneville 2B . . . . . . . . . . . . .. 63.2 32.1 .6 3.0 .8 .3 Mebane140 . . . . . . . . . . . . . 66.7 27.3 .9 3.9 1.1 .3 CA 122 . . . . . . . . . . . . . . . . . . 66.8 29.0 .8 2.0 1.2 .2 CA89A . . . . . . . . . . . . . . . . . . .. 56.7 27.9 3.0 12.0 .3 .1 4 Average . . . . . . . . . . . . . . . . . .. 63.5 29.2 1.3 4.8 1.0 0.2 Percent change from early harvest . . . . . . . . . . . . . . .. +4.8 —-2.4 0.0 —45.8 +25.0 . . . . . . .. Late harvest Deltapine 14 . . . . . . . . . . . . . .. 64.9 30.3 1.6 1.8 1.0 .4 Stoneville2B............... 62.9 33.4 .8 1.4 .8 .7 Mebane 140 . . . . . . . . . . . . . .. 65.4 29.2 1.0 2.3 1.8 .3 CA 122 . . . . . . . . . . . . . . . . . . .. 64.1 30.0 1.6 2.0 1.8 .5 CA89A . . . . . . . . . . . . . . . . . . .. 60.9 33.8 1.0 3.7 .5 .1 Average . . . . . . . . . . . . . . . . . .. 63.6 31.3 1.2 2.3 1.2 0.4 ' Percent change from early harvest . . . . . . . . . . . . . . .. +5.0 +4.7 —8.3 —-204.4 +50.0 . . . . . . .. Percent change from mid- i season harvest . . . . . . . .. +0.2 +7.2 —8.3 -—l08.7 +20.0 . . . . . . .. Foreign Matter Removed by Extractor College Station: N0. 15 Machine. Early harvested strip cotton contained more foreign matter than did cotton harves 8' at mid-season and late in the season (Table 2). The avera total percentages of foreign matter removed from five varieti‘ for early, mid-season and late harvests were 39.4, 36.5 a1 36.4, respectively. This decrease Was due primarily to be defoliation at the latter dates and, consequently, less trash w" harvested with the cotton. This is reflected in the rate of ’_ crease in the percentage of fine trash for the three harv dates (Figure 13). The average percentages of fine trash moved were 7.0, 4.8 and 2.3, respectively, for the three da_ (Table 2). As expected, there Was a small increase in t amount of dirt and sand at the late harvest. THE CLEANING OF MECHANICALLY HARVESTED COTTON 15 A Lubbock: N0. 15 Machine. Table 3 shows the percentage of the different kinds of foreign matter removed by the extractor from 11 varieties harvested early, mid-season and late. These pwere 21.4, 25.4 and 28.2 percent, respectively. The amount of 1' 3. Average percentage of dilferent kinds of foreign matter removed by the extractor from varieties 0f cotton machine stripped with No. 15 machine at early, mid-season and late harvests at Lubbock, 1946-48 Total percent foreign Variety _ Seed cotton Fine Dirt and Invisible matter (uncleaned) Burs Stems trash sand loss removed Early harvest lne14 . . . . . . . . . . . . . .. 74.6 20.7 1.0 1.5 2.0 2 25.4 vllle 2B . . . . . . . . . . . . . .. 75.7 20.6 .6 1.7 1.2 2 24.3 110140 . . . . . . . . . . . . . .. 75.4 19.2 1.0 2.2 1.8 4 24.6 2 . . . . . . . . . . . . . . . . . . .. 77.9 17.6 1.1 2.6 .6 2 22.1 A . . . . . . . . . . . . . . . . . .. 80.8 16.0 .4 2.1 .5 2 19.2 ern Star . . . . . . . . . . . . .. 77.5 19.2 .8 1.4 1.0 1 22.5 er . . . . . . . . . . . . . . . .. 73.4 22.0 .6 2.2 1.5 3 26.6 _ d . . . . . . . . . . . . . . . . . .. 78.0 18.1 1.0 1.6 1.2 1 22.0 proofNo.1 . . . . . . . . . .. 81.1 16.0 .8 1.2 .6 3 18.9 'master . . . . . . . . . . . . . .. 85.3 11.0 .6 2.0 .9 2 14.7 Early . . . . . . . . . . . . . .. 84.6 12.3 .6 1.4 .9 2 15.4 ge . . . . . . . . . . . . . . . . . .. 78.6 17.5 0.8 1.8 1.1 0.2 21.4 Mid-season harvest pine l4 . . . . . . . . . . . . . .. 69.4 23.6 2.8 2.1 1.5 6 30.6 vllle 2B 64.4 29.4 3.0 1.4 1.2 6 35.6 ne 140 . . . . . . . . . . . . . .. 68.4 22.0 1.2 6.5 1.5 4 31.6 22 . . . . . . . . . . . . . . . . . . .. 77.1 19.2 .9 2.0 .7 1 22.9 9A . . . . . . . . . . . . . . . . . . .. 74.7 21.0 1.5 2.5 .7 6 25.3 ern Star . . . . . . . . . . . . .. 77.3 19.2 .8 1.1 1.2 4 22.7 ster . . . . . . . . . . . . . . . .. 69.7 25.1 1.0 1.8 1.9 5 30.3 ed . . . . . . . . . . . . . . . . . .. 74.4 21.6 .6 1.2 1.8 4 25.6 proofNo.1 . . . . . . . . . .. 81.0 16.7 .7 .9 1.0 7 20.0 _master . . . . . . . . . . . . . .. 82.3 14.2 .7 1.2 1.2 4 17.7 aEarly . . . . . . . . . . . . . .. 82.5 14.4 .7 1.0 1.0 4 17.5 ge . . . . . . . . . . . . . . . . . .. 74.6 20.6 1.3 2.0 1.2 0.5 25.4 nt change from early harvest . . . . . . . . . . . . . . .. —5.0 +l7.7 +625 +11.l +9.1 . . . . . . .. +18 7 Late harvest pine 14 . . . . . . . . . . . . . .. 66.6 23.3 3.4 2.3 3.6 8 33 4 ville 2B . . . . . . . . . . . . . .. 60.9 30.8 2.5 1.6 3.8 4 39 1 ne140 . . . . . . . . . . . . . .. 68.4 23.5 1.8 2.6 3.3 4 31 6 22 . . . . . . . . . . . . . . . . . . .. 75.7 16.8 2.3 2.3 2.4 5 24 3 9A . . . . . . . . . . . . . . . . . . .. 73.1 18.7 2.4 1.9 3.0 9 26.9 ern Star . . . . . . . . . . . . .. 70.8 21.8 1.5 1.7 3.8 4 29 2 aster . . . . . . . . . . . . . . . .. 67.7 23.1 2.3 2.4 3.7 8 32 3 ed . . . . . . . . . . . . . . . . . .. 67.4 24.0 1.7 1.8 4.3 8 32.6 proofNo. 1 . . . . . . . . . .. 76.6 16.0 2.2 1.0 3.6 6 23.4 master . . . . . . . . . . . . . .. 81.3 12.0 2.0 .8 3.3 6 18.7 a Early . . . . . . . . . . . . . .. 81.5 12.2 2.0 1.2 2.7 4 18.5 ge . . . . . . . . . . . . . . . . . .. 71.8 20.2 2.2 1.8 3.4 0.6 28 2 nt change from early harvest . . . . . . . . . . . . . . .. ——9.5 +l5.4 +l75.0 0.0 +209.l . . . . . . .. +31.8 ent change from mid- season harvest . . . . . . . .. ——3.9 —2.0 +69.2 —11.1 +183.3 . . . . . . .. +l1.0 1e BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION \\ . w. \ ~\ Figure 13. Comparison of the amounts of different kinds of foreign matter removed by the extractor from a stormproof and a normal boll variety. The amount of fine trash Was smaller in the late harvests. The piles of dirt and sand are smaller for the stormproof (CA 122) variety than for the normal boll (Deltapine 14) variety. foreign matter removed at mid-season increased 18.7 percent over the early harvest. The amount of foreign matter at the late harvest increased 31.8 percent over that at the early har- vest. The increase in foreign matter removed at the late har- vest, however, Was only 11.0 percent over that at mid-season Figure 14. Comparison of amounts of different kinds of foreign matter removed by the extractor from a stormproof and a normal boll variety harvested at Lubbock. Notice the increase in the amount of stems for the late-harvested cottons. THE CLEANING OF MECHANICALLY HARVESTED COTTON 17 (Table 3). The greater increase in the total amount of foreign » matter removed from the early to the mid-season harvest is attributed to the plants being limber and tough at the early harvest and dry and brittle at the mid-season and late harvests. This is shown in the increase in the percentages of stems re- moved at the two later harvests (Figure 14). The increase in stems amounted to 175 percent (Table 3). There was also a 209 percent increase in the percentages of dirt and sand re- moved at the late harvest o-ver that removed at the early har- I vest (Figure 14). This trend is also shown in Texas Station » Progress Report 1134. There is a noticeable difference in the percentage of foreign matter removed from different varieties. Paymaster had the highest percentage of burs and the highest total amount of foreign matter removed at the early harvest. Stoneville 2B had the largest amount of burs and total foreign matter at both the mid-season and late harvests. Stoneville 2B and Delta- pine 14 had the largest amounts of stems at the mid-season and late harvests. All of the stormproof varieties, consisting of CA 122. CA 89A, Stormproof No. 1, Stormmaster and Macha Early, had relatively small amounts of burs and total foreign matter re- moved at all three harvests in comparison with the normal boll varieties, Deltapine 14, Stoneville 2B, Mebane 140, Northern Star, Paymaster and Hi-Bred. This is attributed to more difficult extracting qualities of the stormproof varieties. The stormproof varieties had small amounts of dirt "and sand at the early harvest and averaged less at the mid-season and late harvests. This may be attributed to the difference in the flufiiness of cotton in the bolls. Lubbock: N0. 16 Machine. Where a field tractor-mounted field extractor was used in combination with the stripper, the amounts of the different kinds and the total foreign matter removed averaged less than half the amount removed from regularly stripped cotton (Tables 3 and 4). The average total percentages. for all 11 varieties at the three harvests Were 9.1, 13.2 and 12.3, respectively (Table 4). With the No. 15 machine, the comparable averages were 21.4, 25.4 and 28.2 percent, re- spectively. Table 4 shows that the increase in stems from the early har- vest to the mid-season harvest was 350 percent and the increase of the late harvest over the early harvest was 500 percent. There was, however, only a 33.3 percent increase in the percentage of stems between the late and mid-seaso-n harvests. Tables 3 and 4 definitely show that the amounts of stems, dirt and sand, and the total trash removed, increases greatly when machine-stripping is delayed in the High Plains region until the plants have become dry and brittle and winds have blown dirt and sand into the locks of cotton. 18 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Table 4. Average percentages of ditferent kinds of foreign matter removji extractor from varieties of cotton machine-stripped with No. 16 .3 early, mid-season and late harvests at Lubbock, 1946-47 II e Variety Seed cotton Fine Dirt and Invial‘ (uncleaned) Burs Stems trash sand loan; Early harvest Deltapine 14 . . . . . . . . . . . . . .. 89.4 7.5 .3 1.1 1.6 Stonevflle 2B . . . . . . . . . . . . . .. 92.0 4.8 .2 1.0 1.5 Mebane140 . . . . . . . . . . . . . .. 94.4 3.2 .3 .8 1.1 CA 122 . . . . . . . . . . . . . . . . . . .. 90.5 7.7 .2 1.1 .3 CA89A . . . . . . . . . . . . . . . . . . .. 91.6 6.8 .2 1.0 .2 Northern Star . . . . . . . . . . . . .. 89.7 7.8 .2 1.2 1.0 Paymastel’ . . . . . . . . . . . . . . . .. 88.6 8.3 .3 1.2 1.3 Hi-Bred . . . . . . . . . . . . . . . . . .. 93.7 3.9 .3 .7 1.3 Stormproof No. 1 . . . . . . . . . . . 89.2 9.1 .2 1.0 .3 Stormmaster . . . . . . . . . . . . . . . 92.6 6.2 . 1 .5 .5 Macha Early . . . . . . . . . . . . . .. 88.5 9.6 .3 1.0 .5 Average . . . . . . . . . . . . . . . . . .. 90.9 6.8 0.2 . 1.0 0.9 0. Mid-season harvest Deltapine 14 . . . . . . . . . . . . . .. 82.3 12.8 2.0 1.7 1.0 Stoneville2B............... 86.1 9.1 .7 2.1 1.5 Mebane 140 . . . . . . . . . . . . . .. 86.5 9.8 1.2 1.6‘ .6 CA.122 . . . . . . . . . . . . . . . . . . .. 85.1 11.5 1.2 1.5 .3 CA.89A . . . . . . . . . . . . . . . . . . .. 84.6 12.6 1.1 1.1 .4 Northern Star . . . . . . . . . . . . . . 88.1 9.6 .4 .5 .6 Paymaster . . . . . . . . . . . . . . . . . 88.7 9. 3 . 5 .8 .4 Hi-Bred . . . . . . . . . . . . . . . . . .. 88.0 7.7 .8 1.8 1.2 Stormproof No. 1 . . . . . . . . . . . 86. 7 10. 7 . 7 . 6 . 3 1 Stormmaster . . . . . . . . . . . . . .. 91.2 7.2 .3 .5 .3 Macha Early . . . . . . . . . . . . . .. 87. 5 10.3 . 5 .5 .3 Average . . . . . . . . . . . . . . . . . .. 86.8 10.0 0.9 1.2 0.6 0., Percent change from early harvest . . . . . . . . . . . . . . . . +4. 7 +47. 1 +3500 +20.0 —50.0 Late harvest Deltapine 14 . . . . . . . . . . . . . .. 84.6 9.4‘ 2.6 1.2 1.7 Stoneville 2B . . . . . . . . . . . . . .. 91.2 4.6 1.5 .6 1.5 Ddebane 140 . . . . . . . . . . . . . .. 89.8 6.3 1.4 _1.2 1.1 CA 122 . . . . . . . . . . . . . . . . . . .. 86.8 10.5 1.0 1.0 .6 CA.89A . . . . . . . . . . . . . . . . . . .. 84.8 10.7 1.4 1.6 1.0 Northern Star . . . . . . . . . . . . . . 87.3 9.4 .8 .9 1.4 k Paymaster . . . . . . . . . . . . . . . .. 86.1 10.9 1.1 .5 1.3 " Hi-Bred . . . . . . . . . . . . . . . . . .. 88.3 7.8 1.3 .7 1.3 ; Stormproof No. 1 . . . . . . . . . . . 88.3 9. 6 .7 .6 .7 .- ;j Stormmaster . . . . . . . . . . . . . . . 90. 5 7.1 .4 . 6 .9 ‘ g Macha Early . . . . . . . . . . . . . .. 87.4 10.2 .8 .8 .6 Average . . . . . . . . . . . . . . . . . .. 87.7 s.s 1.2 0.9 1.1 o; Percent‘ change from early harvet . . . . . . . . . . . . . . . . ——3.6 +29.4 +500. 0 —1.1 +22.2 . . . . . a Percent change from mid- season harvest . . . . . . . . . +1 . 0 —13. 6 +33 . 3 —33 . 3 +83 . 3 Foreign Matter Removed by Cleaner College Station: N0. 15 Machine. The samples of extr J seed cotton contained burs, stems, fine trash and dirt and 1' that were not removed in the extracting process (Figure I l L’ I 99359? l -l ‘EIBIOPZQG EUIEVIPIOOZQU THE CLEANING OF MECHANIGALLY HARVESTED COTTON 19 Table 5 shows the percentages of the different kinds of foreign matter removed and the total percentage removed for the three , harvests at College Station. The to-tal percentages of foreign i matter removed decreased consistently from the early harvest z i through the mid-season to the late harvest, or 11.7, 10.5 and ' ' 7.2, respectively. This rate of decrease is comparable with the l? decrease of foreign matter removed in the extracting process ' i (Table 2). The percentage o-f fine trash removed in cleaning decreased more than any other kind of foreign matter con- tained in the cotton (Figure 15). This, apparently, was due to the excessive amounts of green leaf harvested with the cotton because of poor defoliation at the earlier harvests. The average percentages of burs and stems, and dirt and sand for all five varieties did not change greatly for the three harvests at Col- lege Station. The greatest differences among varieties Were in the percentage of fine trash removed. Stoneville 2B had a con- sistently high amount of fine trash removed in each harvest. le 5. Average percentages of dilferent kinds of waste removed by the cleaner from varieties of cotton machine stripped with N0. 15 machine at early, mid-season and late harvests at College Station, 1946-48 Total percent Variety Motes, foreign Clean seed burs and Fine Dirt and Invisible matter cotton stems trash sand loss removed Early harvest pine 14 . . . . . . . . . . . . . . . . . . . . .. 88.6 4.1 6.0 .8 .5 11.4 evllle 2B . . . . . . . . . . . . . . . . . . . .. 83.4 4.8 10.3 .6 .9 16.6 anel40 . . . . . . . . . . . . . . . . . . . . .. 90.2 3.9 4.7 .6 .6 9.8 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 92.9 3.1 3.2 .6 .2 7.1 89A. . . . . . . . . . . . . . . . . . . . . . . . .. 86.2 5.6 7.0 .3 .9 13.8 age . . . . . . . . . . . . . . . . . . . . . . . . .. 88.3 4.3 6.2 0.6 0.6 11.7 Mid-season harvest pine 14 . . . . . . . . . . . . . . . . . . . . .. 89.3 4.5 4.7 .9 6 10.7 evllle 2B . . . . . . . . . . . . . . . . . . . .. 87.9 4.2 6.4 .9 .6 12.1 ane 140 . . . . . . . . . . . . . . . . . . . . .. 89.7 3.5 5.3 1.0 .5 10.3 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 93.3 3.2 2.6 .8 .1 6.7 89A . . . . . . . . . . . . . . . . . . . . . . . . .. 87.3 5.0 6.9 .3 5 12.7 age . . . . . . . . . . . . . . . . . . . . . . . . .. 89.5 4.1 5.1 0.8 0.5 10.5 cent change from early harvest. . +1.4 ——4. 9 —2l.6 +33.3 . . . . . . . . . . -—1l.4 Late harvest tapine 14 . . . . . . . . . . . . . . . . . . . . .. 91.7 4.1 3.2 .8 .2 8.3 eville2B . . . . . . . . . . . . . . . . . . . .. 92.2 3.9 3.2 .6 .1 7.8 bane 140 . . . . . . . . . . . . . . . . . . . . .. 93.1 3.6 2.2 .8 .3 6.9 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 92.4 4.1 2.4 1.0 .1 7.6 89A . . . . . . . . . . . . . . . . . . . . . . . . .. 94.6 2.9 2.1 .3 .1 5.4 rage . . . . . . . . . . . . . . . . . . . . . . . . .. 92.8 3.7 2.6 0.7 0.2 7.2 cent change from early harvest. . . +5.1 —16.2 —l38. 5 +16. 7 -—200.0 —62.5 cent change from mid-season i harvest . . . . . . . . . . . . . . . . . . . . . .. +3 - 7 —10-8 —96-2 —14-3 —150-0 —45-3 20 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Lubbock: N0. 15 Machine. Table 6 shows the percentages of the different kinds of foreign matter removed by the cleane . from samples of extracted cotton for 11 varieties machine-f. stripped early, mid-season and late at Lubbock. The averagf total percentage of foreign matter removed for all varieti Table 6. Average percentages 0f difierent kinds of foreign matter removed cleaner from varieties of cotton machine stripped with No. 15 ma early, mid-season and late harvests at Lubbock, 1946-48 Variety Motes, Clean seed burs and Fine Dirt and Invisible cotton stems trash sand loss r l Early harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . . .. 92.0 2.4 3.9 1.4 .3 l‘ Stoneville 2B . . . . . . . . . . . . . . . . . . . .. 90.0 3.2 5.5 1.0 .3 l‘ Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 92.0 2.6 3.5 1.4 .5 CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 93.7 2.3 3.2 .6 .2 CA 89A . . . . . . . . . . . . . . . . . . . . . . . . .. 94.8 2.3 2.2 .5 .2 Northern Star . . . . . . . . . . . . . . . . . . . .. 91.2 4.2 3.2 1.0 .4 Paymaster . . . . . . . . . . . . . . . . . . . . . . .. 91.0 3.0 4.2 1.5 .3 Hi-Bred . . . . . . . . . . . . . . . . . . . . . . . . .. 93.3 2.4 3.0 1.0 .3 Stormproof No. 1 . . . . . . . . . . . . . . . . . . 94.0 2.4 2. 7 .5 .4 Stormmaster . . . . . . . . . . . . . . . . . . . . . . 95. 4 2. 2 1 . 6 .5 .3 Macha Early . . . . . . . . . . . . . . . . . . . . .. 95.1 2.2 2.0 .6 .1 Average . . . . . . . . . . . . . . . . . . . . . . . . .. 93.0 2.6 3.2 0.9 0.3 Mid-season harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . . .. 90.9 3.4 3.9 1.6 .2 Stoneville 2B . . . . . . . . . . . . . . . . . . . .. 89.6 5.4 3.0- 1.7 .3‘ . Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 92.3 3.2 2.8 1.4 .3 '3 CA122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 95.5 1.7 2.2 .5 .1 * CA89A . . . . . . . . . . . . . . . . . . . . . . . . .. 95.0 2.3 1.9 .6 .2 Northern Star . . . . . . . . . . . . . . . . . . . .. 93.0 1.9 3.2 1.6 .3 Paymaster . . . . . . . . . . . . . . . . . . . . . . .. 91.8 2.1 3.8 1.8 .5 _ 93.2 2. 4 2 . 4 1 . 7 . 3 l- Storrnproof No. 1 . . . . . . . . . . . . . . . . . . 94. 9 2.6 1.3 .8 .4 "l? Stormmaster . . . . . . . . . . . . . . . . . . . . . . 96. 4 1.2 1 . 6 .5 .3 ** Macha Early . . . . . . . . . . . . . . . . . . . . .. 96.2 1.6 1.6 .4 .2 Average . . . . . . . . . . . . . . . . . . . . . . .. 93.5 2.5 2.5 1.2 0.3 Percent change from early harvest. . +. 5 ——4.0 ~28. 0 +33.3 . . . . . . . . . . Late harvest Deltapine 14 . . . . . . . . . . . . . . . . . . .. 89.3 3.5 3.6 3.1 .5 Stoneville 2B . . . . . . . . . . . . . . . . . . . .. 85.8 5.4 4.8 3.4 .6 Mebane 140 . . . . . . . . . . . . . . . . .. .. 91.6 3.0 2.8 2.3 .3 CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 94.4 2.2 1.9 1.3 .2 CA89A . . . . . . . . . . . . . . . . . . . . . . . . .. 94.1 2.0 1.9 1.7 .3 _ Northern Star . . . . . . . . . . . . . . . . . . . .. 90. 7 3.7 2.2 2.8 .6 I Paymaster . . . . . . . . . . . . . . . . . . . . . . .. 88.6 4.0 3.4 3.2 .8 5 Hi-Bred . . . . . . . . . . . . . . . . . . . . . . . . .. 90.0 4.0 2.7 2.9 .4 Stormproof No. 1 . . . . . . . . . . . . . . . . .. 93. 1 2.4 1.8 2.3 .4 Stormmaster . . . . . . . . . . . . . . . . . . . . . . 95.2 1 . 8 1 . 0 1. 5 .5 Macha Early . . . . . . . . . . . . . . . . . . . . .. 94.8 2.4 1.3 1.3 .2 Average . . . . . . . . . . . . . . . . . . . . . . . . .. 91.6 3.1 2.5 .4 0.4 Percent change form early harvest.. . ——1.5 +l9.2 -——28.0 +166. 7 . . . . . . . . .. Percent change from mid-season harvest . . . . . . . . . . . . . . . . . . . . . .. ——2. l +24. 0 0 0 +100. 0 . . . . . . . . . . THE CLEANING OF MECHANICALLY HARVESTED COTTON 21 f was the lowest for the mid-season harvest. These percentages \ were 7.0, 6.5 and 8.4, respectively. The late-harvested cotton gave up 20 percent more foreign matter than the early har- vested cotton. This, apparently, was due to the excessive amounts of foreign matter collected in harvesting at the late dates and the inability of the extractor to remove the large amounts of foreign matter present in the cotton. The greatest increase in the kinds of foreign matter removed was in the dirt and sand. The average percentages of dirt and sand removed for all varieties for the three harvests were 0.9, 1.2 and 2.4, respectively. The percentage of dirt and sand re- moved at the mid-season harvest was 33.3 more than the earlier harvest. The late harvest had 166 percent more dirt and sand than the early harvest and 100 percent more than the cotton stripped in mid-season. The climate, rainfall and frequency of storms accompanied by high winds are factors in the amount of dirt and sand in the cotton at any date of harvest. The highest Pfircentage of total foreign matter was removed from Stoneville 2B for all three harvests. The amount of for- eign matter removed by the cleaner increased with later harvestings, and was 10.0, 10.4 and 14.2 percent, respectively. There was more fine trash removed than" any other kind of for- eign matter. ‘ The lowest percentage of total foreign matter removed by the cleaner for all three harvests was from Stormmaster, and was 4.6, 3.6 and 4.8, respectively. More burs and stems were removed at the early and late harvests than any other kind of foreign matter. A slightly higher percentage of fine trash than of burs and stems was removed at the mid-season harvest. Table 6 shows that, as a general rule, the normal bo-ll types of cotton gave up more foreign matter in cleaning than the stormproof types (Figure 16). This was apparently because more burs were left in the seed cotton of the stormproof cottons by the extractor than in the normal boll types. On the other hand, more fine trash was left in the seed cotton of the normal boll types than in the stormproof types. It is obvious that small particles of fine leaf trash can be removed by cleaning equip- ment from seed cotton more easily than large particles of burs. Tables 2, 3, 5 and 6 show that more foreign matter was col- lected at College Station in machine stripping, where green foliage was on the plants from poor defoliation, than from cottons harvested at Lubbock after a killing freeze. Lubbock: N0. 16 Machine. Table 7 shows the percentages of difierent kinds of foreign matter removed by the cleaner from cotton that had been partially extracted by a tractor- mounted field extractor and finished by a stationary laboratory 22 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 15. Comparison of the amounts of different kin s of foreign matter removed by the cleaner from cotton stripped early, mid-season and late at College Station. The piles of fine trash become smaller with later har- vesting. extractor. Only 0.7 percent less total foreign matter Was r moved by the cleaner from cotton harvested by the No. 1 machine at the early and mid-season harvests (Table 7), tha Twas removed from the cotton harvested by the No. 15 machin’ (Table 6). The No. 15 machine, at the late harvest, remov 3.4 percent more total foreign matter than the No. 16 machin This seems to indicate that the No. 16 machine removed con siderable amounts of foreign matter at the late harvest. Figure 16. Comparison of the amounts of foreign matter removed by the cleaner from a stormproof and a normal boll variety stripped at College Station. THE CLEANING OF MECHANICALLY HARVESTED COTTON 23 it 7. Average percentages of difl"erent kinds of foreign matter removed by the cleaner from varieties 0f cotton machine stripped with No. 16 machine at early, mid-season and late harvests at Lubbock, 1946-47 Total percent Variety Motes, foreign Clean seed burs and Fine Dirt and Invisible matter cotton stems trash sand loss removed Early harvest ne 14 . . . . . . . . . . . . . . . . . . . . .. 92.5 2.5 2.6 2.0 .4 7.5 ville2B . . . . . . . . . . . . . . . . . . . .. 93.3 2.1 2.9 1.5 .2 6.7 ne 140 . . . . . . . . . . . . . . . . . . . . .. 93.9 2.3 2.2 1.2 .4 6.1 2 . . . . . . . . . . . . . . . . . . . . . . . . . .. 94.9 2.5 1.4 1.1 .1 5.1 A . . . . . . . . . . . . . . . . . . . . . . . . .. 95.2 2.7 1.6 .2 .3 4.8 ern Star . . . . . . . . . . . . . . . . . . . .. 89.9 5.3 2.9 1.2 .7 10.1 ster . . . . . . . . . . . . . . . . . . . . . . .. 91.5 3.0 3.6 1.2 .7 8.5 e . . . . . . . . . . . . . . . . . . . . . . . . .. 94.6 1.7 1.5 1.7 .5 5.4 proofNo.1 . . . . . . . . . . . . . . . . .. 94.5 3.1 1.7 .6 .1 5.5 master . . . . . . . . . . . . . . . . . . . . .. 95.7 2.5 1.1 .5 .2 4.3 jEarly . . . . . . . . . . . . . . . . . . . . .. 94.8 2.2 2.2 .3 .5 5.2 e . . . . . . . . . . . . . . . . . . . . . . . . .. 93.7 2.7 2.2 1.0 0.4 6.3 Mid-season harvest plne 14 . . . . . . . . . . . . . . . . . . . . .. 92.8 2.3 4.0 7 .2 7.2 vllle 2B . . . . . . . . . . . . . . . . . . . .. 91.1 4.7 2.9 7 .6 8.9 ne 140 . . . . . . . . . . . . . . . . . . . . .. 92.4 3.2 3.2 8 .4 7.6 22 . . . . . . . . . . . . . . . . . . . . . . . . . .. 93.6 2.2 3.2 6 .4 6.4 . . . . . . . . . . . . . . . . . . . . . . . . .. 94.0 2.4 2.9 5 .2 6.0 ern Star . . . . . . . . . . . . . . . . . . . .. 94.4 1.9 2.7 8 .7 5.6 aster . . . . . . . . . . . . . . . . . . . . . . .. 94.9 2.0 1.8 1 0 .3 5.1 ‘ed . . . . . . . . . . . . . . . . . . . . . . . . .. 94.5 2.7 1.8 7 .3 5.5 proofNo. 1 . . . . . . . . . . . . . . . . .. 95.8 .2 3.0 4 .6 4.2 master . . . . . . . . . . . . . . . . . . . . .. 96.6 1.6 1.1 3 .4 3.4 ’aEarly . . . . . . . . . . . . . . . . . . . . .. 96.0 2.1 1.2 3 .4 4.0 ige . . . . . . . . . . . . . . . . . . . . . . . . .. 94.2 2.3 2.5 0.6 0.4 5.8 _ ent change from early harvest. . +.5 ——17. 4 +l3.6 —-66.7 . . . . . . . . . . —8.6 Late harvest pme 14 . . . . . . . . . . . . . . . . . . . . .. 93.0 2.6 2.6, 1.4 .4 7.0 evllle 2B . . . . . . . . . . . . . . . . . . . .. 90.6 4.7 2.4 1.5 .6 9.2 ‘ne 140 . . . . . . . . . . . . . . . . . . . . .. 94.0 2.4 2.2 1.0 .4 6.0 2 . . . . . . . . . . . . . . . . . . . . . . . . . .. 95.2 2.3 1.8 .3 .4 4.8 89A . . . . . . . . . . . . . . . . . . . . . . . . .. 94.8 2.4 2.2 .5 .1 5.2 _hern Star . . . . . . . . . . . . . . . . . . . .. 97.6 1.6 .4 .1 .3 2.4 aster . . . . . . . . . . . . . . . . . . . . . . .. 97.8 1.3 .4 .2 .3 2.2 Bred . . . . . . . . . . . . . . . . . . . . . . . . .. 94.8 2.3 1.7 .9 .3 5.2 mproofNo. 1 . . . . . . . . . . . . . . . . .. 95.6 2.4 .9 .6 .5 4.4 mmaster . . . . . . . . . . . . . . . . . . . . .. 95.7 2.0 .8 .8 .7 4.3 haEarly . . . . . . . . . . . . . . . . . . . . .. 95.5 2.5 .9 .5 .6 4.5 ‘ge . . . . . . . . . . . . . . . . . . . . . . . . .. 95.0 2.4 1.5 0.7 0.4 5.0 ent change from early harvest. . +1.4 ~12. 5 —46. 7 —42. 9 . . . . . . . . . . ——26.0 “cent change from mid-season harvest . . . . . . . . . . . . . . . . . . . . .. +0.9 —4.3 —-66.7 +16.7 . . . . . . . . . . —l6.0 Foreign Matter Removed by Ginning College Station: N0. 15 Machine. Table 8 shows that the average percentage of the different kinds of foreign matter removed from the five varieties stripped at College Station was only 1.4 for both early and mid-season harvests. There Was, 24 BULLETIN 720, TEXASiAGRlCULTURAL EXPERIMENT STATION however, a 14.3 percent decrease in fine trash for the late har-i vest. This is in line with the decreased amounts of fine trash; removed from the samples. in the extracting and cleaning,‘ PPOCGSSGS. Lubbock: N0. 15 Machine. The average percentages 0f dif-j ferent kinds of foreign matter removed by ginning from 11 a: varieties of cotton stripped with the No. 15 machine early;- mid-season and late at Lubbock are shown in Table 9. There; was no difference in the average amounts of fine trash removed; by ginning for all three harvests. Only 0.06 percent less dirtv“ and sand was removed at the mid-season than for the early and late harvests. The percentages of dirt and sand removed by ginning fromi the samples of the 11 varieties for all three harvests averaged Table 8. Average percentages of dilferent kinds of foreign matter removed in, ning, the percentages of seed and lint, the grade and staple of _, machine-stripped with N o. 15 machine at early, mid-season and late h‘ . at College Station, 1946-48 " s Total _ Variety Fine Dirt and Invisible trash ; trash sand loss loss Seed Lint Grade* x Early harvest Deltapine 14...’ . . . . . . . . . . .. .7 .2 .5 1.4 61.7 36.9 1.3 Stoneville 2B . . . . . . . . . . . . .. .8 .2 .2 1.2 64.8 34.0 8.5 Mebane 140 . . . . . . . . . . . . . .. .8 .3 .4 1.5 60.1 38.4 6.8 CA 122 . . . . . . . . . . . . . . . . . . .. .8 .3 .5 1.6 61.4 37.0 7.0 CA89A . . . . . . . . . . . . . . . . . .. .7 .1 .2 1.0 61.6 37.4 9.0 Average . . . . . . . . . . . . . . . . . .. 0.8 0.2 0.4 1.4 61.9 36.7 7.8 ' Mid-season harvest Deltapine14 . . . . . . . . . . . . . .. .8 .2 .6 1.6 61.3 37.1 8.0 Stoneville 2B . . . . . . . . . . . . .. 1.0 .1 .5 1.6 65.8 32.6 8.5 Mebane 140 . . . . . . . . . . . . . .. .7 .2 .5 1.4 60.0 38.6 8.2 CA 122 . . . . . . . . . . . . . . . . . . .. .8 .2 .3 1.3 61.5 37.2 7.5‘ CA89A . . . . . . . . . . . . . . . . . .. .7 .1 .2 1.0 65.6 33.4 9.0 _ Average . . . . . . . . . . . . . . . . . .. 0.8 0.2 0.4 1.4 62.8 35.8 8.2 Percent change from early harvest . . . . . . . . . . . . . . .. 0.0 0.0 0.0 0.0 +1.4 —2.5 . . . . . . . .. Late harvest Deltapine 14 . . . . . . . . . . . . . .. .7 .2 .3 1.2 61.5 37.3 8.0 Stoneville 2B . . . . . . . . . . . . .. .6 .2 .2 1.0 65.3 33.7 8.5 Mebane 140 . . . . . . . . . . . . . .. .9 .3 .2 1.4 58.8 39.8 8.2 CA 122 . . . . . . . . . . . . . . . . . . .. 1.0 .2 .5 1.7 59.6 38.7 7.5 .~ CA89A . . . . . . . . . . . . . . . . . .. .5 .1 .1 .7 64.5 34.8 9.0 Average . . . . . . . . . . . . . . . . . .. 0.7 0.2 0.3 1.2 61.9 36.9 8.2“ Percent change from early harvest . . . . . . . . . . . . . . .. —14.3 0.0 —33.3 -—l6.7 0.0 +0.5 . . . . . . . . .. Percent change from mid- season harvest . . . . . . . . . —l4.3 0.0 —33.3 —16. 7 -—1 . 4 +3.1 . . . . . . . . . *5=M 6=SLM 7=LM 8=SGO 9=G0 10 =BG THE CLEANING OF MECHANICALLY HARVESTED COTTON ' 25 0.2 for the early and late harvest and 0.06 for the mid-season harvest. The percentages of fine trash ranged from 0.4 to 0.9 for the different varieties at the early harvest and from 0.4 to 0.8 at the mid-season and late harvests. Slightly higher per- centages of fine trash were removed from the sto-rmproof types, CA 122, CA 89A, Stormproof No. 1, Stormmaster and Macha lble 9. Average percentages of difierent kinds of foreign matter removed in gin- ning, the percentages of seed and lint and the grade and stapile of cotton v machine-stripped with No. 15 machine at early, mid-season and late harvests at Lubbock, 1946-48 ‘ Total u Variety Fine Dirt and Invisible trash f]. trash sand loss loss Seed Lint Grade Staple ‘,3 _ Early harvest tapine 14 . . . . . . . . . . . . . .. .4 .2 .5 1.1 59.5 39 4 7.5 29 neville 2B . . . . . . . . . . . . .. .8 .2 .5 1.5 63.2 35 3 9.0 31 ane140 . . . . . . . . . . . . . .. .5 .2 .5 1.2 59.6 39 2 8.0 28 122 . . . . . . . . . . . . . . . . . . .. .7 .2 .2 1.1 61.9 37 0 7.0 30 89A . . . . . . . . . . . . . . . . . .. .8 ,1 .2 1.1 61.5 37.4 7.0 30 thern Star . . . . . . . . . . . . .. .4 .2 .4 1.0 61.0 38.0 8.0 29 master . . . . . . . . . . . . . . . .. .7 .2 .4 1.3 60.6 38.1 7.5 28 Bred . . . . . . . . . . . . . . . . . .. .4 .2 .5 1.1 56.5 42.4 6.5 26 mproofNo. 1 . . . . . . . . . .. .6 .2 .5 1.3 59.6 39.1 8.0 26 mmaster . . . . . . . . . . . . . .. .9 .2 .6 1.7 61 0 37.3 8.0 30 ha Early . . . . . . . . . . . . . .. .7 .2 .6 1.5 63.1 35.4 7.5 29 rage . . . . . . . . . . . . . . . . . .. 0.6 0.2 0.4 1.2 60.7 38.1 7.6 28.7 Mid-season harvest tapine 14 . . . . . . . . . . . . . .. .5 .2 .2 .9 59.1 40.0 10.0 32 eville 2B . . . . . . . . . . . . .. .5 .2 .2 .9 61.0 38.1 10.0 30 ane 140 . . . . . . . . . . . . . .. .5 .1 .4 1.0 59.7 39.3 9.0 26 122 . . . . . . . . . . . . . . . . . . .. .7 .1 .6 1.4 60.6 38.0 8.0 29 89A . . . . . . . . . . . . . . . . . .. .6 .1 .4 1.1 60.7 38 2 10.0 30 hern Star . . . . . . . . . . . . .. .4 .2 .8 1.4 60.5 38 1 10.0 30 master . . . . . . . . . . . . . . . .. .5 .1 .4 1.0 59.6 39 4 10.0 ,28 Bred . . . . . . . . . . . . . . . . . .. .4 .1 .6 1.1 57.2 417 9.0 26 mproofNo. 1 . . . . . . . . . .. .6 .2 .5 1.3 59.9 38.8 9.0 28 mmaster . . . . . . . . . . . . . .. .8 .2 .5 1.5 60.7 37 8 10.0 28 ha Early . . . . . . . . . . . . . .. .8 .1 .5 1.4 62.3 36.3 9.0 , 29 ‘ ge . . . . . . . . . . . . . . . .. 0.6 o 14 0.5 1.2 60.1 38.7 9.3 29.0 ent change from early harvest . . . . . . . . . . . . . . .. 0.0 ——42.8 . . . . . . . . .. 0.0 —1.0 +1.6 . . . . . . . . . . . . .. Late harvest pine 14 . . . . . . . . . . . . . .. .6 .2 .2 1.0 59.8 39.2 9.0 29 eville 2B . . . . . . . . . . . . .. .8 .2 .2 1.2 62.8 36.0 10.0 31 ane 140 . . . . . . . . . . . . . .. .4 .2 .4 1.0 61.0 38.0 8.0 26 122 . . . . . . . . . . . . . . . . . . .. .6 .1 .6 1.3 61.5 37.2 7.5 30 89A . . . . . . . . . . . . . . . . . .. .6 .2 .4 1.2 61.6 37.2 10.0 30 hern Star . . . . . . . . . . . . .. .5 .2 .5 1.2 61.3 37.5 8.0 30 aster . . . . . . . . . . . . . . . .. .6 .2 .1 .9 60.8 38.3 10.0 28 red . . . . . . . . . . . . . . . . . .. .4 .2 .7 1.3 57.3 41.4 8.0 26 mproofNml . . . . . . . . . .. .4 .2 .6 1.2 60.9 37.9 8.0 29 mmaster . . . . . . . . . . . . . .. .8 .2 .4 1.4 61.6 37.0 9.0 .28 ha Early . . . . . . . . . . . . . .. .8 .2 .7 1.7 63.7 34 6 8.0 30 V ge . . . . . . . . . . . . . . . . . .. 0.6 0.2 0.4 1.2 61.1 37 7 8.6 28.9 ient change from early harvest . . . . . . . . . . . . . . .. 0.0 0.0 . . . . . . . . .. 0.0 +0.7 —l.1 . . . . . . . . . . . . .. nt change from mid- p‘ season harvest . . . . . . . .. 0.0 +42.8 . . . . . . . . .. 0.0 +1.7 —2.6 . . . . . . . . . . . . .. 26 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Early than from the ‘normal boll types, Deltapine 14, Stoneville 2B, Mebane 140, Northern Star, Paymaster and Hi-Bred. The “ short staple Hi-Bred and Mebane 140 varieties were consist- ently 10W for all three harvest dates. The variation in the percentages of fine trash remove-d by ginning may be attributed t0 the degree of cleanliness of the Table 10. Average percentages of different kinds 0f foreign matter removed in t ning, the percentages of seed and lint and the grade and staple of c machine-stripped with N0. 16 machine at early, mid-season and late vests at Lubbock, 1946-47 Total Variety Fine Dirt and Invisible trash trash sand loss loss Seed Lint Grade Early harvest Deltapine 14 . . . . . . . . . . . . . .. .3 .1 .3 .7 59.9 39.4 7.0 Stoneville 2B . . . . . . . . . . . . . . .2 .1 .5 .8 61.2 38.0 6.0 Mebane140 . . . . . . . . . . . . . .. .2 .1 .1 .4 59.3 40.3 5.0 CA 122 . . . . . . . . . . . . . . . . . . .. .5 .1 .6 1.2 61.5 37.3 7.0 CA89A . . . . . . . . . . . . . . . . . . .. .5 .1 .4 1.0 63.5 35.5 6.0 Northern Star . . . . . . . . . . . . . . .5 . 1 .2 .8 60.5 38.7 5.5 Paymaster . . . . . . . . . . . . . . . .. .4 .1 .5 1.0 59.6 39.4 5.5 Hi-Bred . . . . . . . . . . . . . . . . . .. .3 .1 .9 1.3 57.6 41.1 5.0 Stormpro0fN0.1 . . . . . . . . . .. .5 .1 .6 1.2 59.2 39.6 6.0 Stormmaster . . . . . . . . . . . . . .. .6 .1 .8 1.5 61.6 36.9 6.0 Macha Early . . . . . . . . . . . . . .. .7 .1 .3 1.1 63.2 35.7 5.5 Average . . . . . . . . . . . . . . . . . .. 0.4 0.1 0.5 1.0 60.6 38.4 5.9 - Mid-season harvest Deltapine 14 . . . . . . . . . . . . . .. .4 .2 .6 1.2 58.8 40.0 8.5 Stoneville 2B . . . . . . . . . . . . .. .4 . 1 .9 1.4 60.3 38.3 10.0 Mebane140 . . . . . . . . . . . . . .. .3 .1 .7 1.1 58.7 40.2 7.0 CA 122 . . . . . . . . . . . . . . . . . . .. 1.0 .2 .5 1.7 60.2 38.1 6.0 CA 89A . . . . . . . . . . . . . . . . . .. .5 .2 .3 .8 60.3 38.8 7.5 NorthernStar . . . . . . . . . . . . .. .5 .1 1.0 1.6 60.4 38.0 7.0 Paymaster . . . . . . . . . . . . . . . .. .5 .2 .9 1.6 59.0 39.4 7.0 Hi-Bred . . . . . . . . . . . . . . . . . .. .3 .1 O 1.0 1.4 55.1 43.5 7.0 StormproofNml . . . . . . . . . .. .6 .1 .8 1.5 59.0 39.5 6.0 Stormmaster . . . . . . . . . . . . . .. .6 .1 .7 1.4 61.3 37.3 6.5 Macha Early . . . . . . . . . . . . . .. .7 .1 1.1 1.9 63.0 35.1 6.0 Average . . . . . . . . . . . . . . . . . .. 0.5 0.1 0.8 1.4 59.7 38.9 7.2 Percent change from early harvest . . . . . . . . . . . . . . .. +25.0 0.0 +60.0 +40.0 —1.5 +1.3 . . . . . . . . .. Late harvest Deltapine 14 . . . . . . . . . . . . . .. .4 .2 .4 1.0 59.5 39.5 9.0 Stoneville 2B . . . . . . . . . . . . .. .4 . 1 .3 .8 61.4 37.8 10.0 Mebane 140 . . . . . . . . . . . . . .. .4 .1 .2 .7 59.2 40.1 8.0 CA 122 . . . . . . . . . . . . . . . . . . .. .6 .2 .4 1.2 60.8 38.0 6.5 CA89A . . . . . . . . . . . . . . . . . .. .5 .1 .4 1.0 61.0 38.0 7.5 Northern Star . . . . . . . . . . . . .. .4 .1 .1 .6 61.4 38.0 8.0 Paymaster . . . . . . . . . . . . . . . .. .4 .1 .1 .6 61.0 38.4 8.0 Hi-Bred . . . . . . . . . . . . . . . . . .. .3 .1 .5 .9 57.0 42.1 8.0 StormproofNml . . . . . . . . . .. .6 .1 .6 1.3 59.9 38.8 7.0 Stormmaster . . . . . . . . . . . . . .. .8 .1 .8 1.7 62.7 35.6 6.0 Macha Early . . . . . . . . . . . . . .. .7 .1 .8 1.6 64.2 34.2 7.0 Average . . . . . . . . . . . . . . . . . .. 0.5 0.1 0.4 1.0 60.8 38.2 7.7 Percent change from early harvest . . . . . . . . . . . . . . .. +25.0 0.0 ——25.0 0.0 +0.3 —0.5 . . . . . . . . . .. Percent change from mid- _ season harvest . . . . . . . .. 0.0 0.0 —l00.0 0.0 +1.8 —l.8 . . . . . . . . .. THE CLEANING OF MECHANICALLY HARVESTED COTTON 27 seed cotton. Hi-Bred and Mebane 140 have good cleaning qual- ities while the stormproof varieties contain large amounts of burs because of their poor extracting qualities. The 20-saw laboratory gin had only one set of ribs, a plain-breasted gin, while the standard size gin is equipped with two sets of ribs and is called a do-uble-breasted gin. It also has huller rolls to take out most of the burs. A double-breasted huller gin would remove higher percentages of burs and fine trash than the laboratory gin use-d in these studies. Lubbock: N0. 16 Machine. Table 1O shows the percentages of foreign matter removed in ginning from cotton stripped with the No. 16 machine. The differences in the amounts of foreign matter removed from the 11 varieties harvested early, mid-season and late are similar to those obtained for the No. 15 machine. Higher percentages of foreign matter were re- moved from the stormproof types than from the normal bo-ll types. Total Pounds 0f Foreign Matter Removed in Extracting, Cleaning and Ginning The foregoing data have shown the percentage of foreign matter removed from the sample Weight at the beginning of each processing step. Tables 11, 12 and 13 show the average Weights of the original sample, and the actual total weights of the foreign matter removed in extracting, cleaning and gin- ning of the machine-stripped cotton at College Station and Lubbock for the three harvests. The foreign matter removed in the spinning tests for lint samples of machine-stripped cotton could not be added to that removed in extracting, cleaning and ginning because all of the lint was not used in the spinning tests. College Station: No. 15 Machine. The average weights of the samples of stripped cotton at the early, mid-season and late harvests were 56.5, 58.5 and 54.3 pounds, respectively (Ta- ble 11). The average foreign matter removed by the extractor was 22.1, 21.1 and 19.7 pounds, respectively. The average weights of the foreign matter removed by the cleaner were 3.6, 3.3 and 2.3 pounds, respectively, while the amounts re- moved in ginning were 0.3, 0.4 and 0.3 pound, respectively. The average total foreign matter removed was 26.0, 24.8 and 22.3 pounds, respectively, for the five varieties stripped at early, mid-season and late harvests. The percentages of the total foreign matter removed of the original sample were 46.5, 42.9 and 41.1, respectively. The amount and percentage of foreign matter decreased for the later harvests because better defoliation was obtained. 28 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION j It is of interest to note that, at College Station, from 4 l to 46.5 percent of the material harvested Was removed as f a; g eign matter in the extracting, cleaning and ginning process» l Lubbock: N0. 15 Machine. Table 12 shows that the avert sizes of the sample 0-f machine-stripped cotton for the thr_ harvests were 37.5, 40.0 and 39.5 pounds, respectively, for i; No. 15 machine. The total average weights of foreign ma K removed by extracting, cleaning and ginning Were 10.6, 1 ' and 13.5 pounds, respectively. The average percentages of t‘ total foreign matter removed of the original sample were 28. 31.1 and 34.6 pounds, respectively. It is noted here, as abov that at late harvest there was an increase in the amount R percentage of foreign matter removed. a .7, Table 11. Average weight of original sample and waste removed by ext cleaner and gin from machine stripped cotton at College Station? N0. 15 machin.e, 1946-47 l a Total . Foreign matter removed by foreign =._ Variety Original matter P _ i sample Extractor Cleaner Gin removed o 1 (lbs.) (lbs.) (lbs.) (lbs.) (lbs.) an Early harvest Deltapine 14 . . . . . . . . . . . . . .. 62.2 22.7 3.6 .4 26.7 Stoneville 2B . . . . . . . . . . . . . .. 50.0 18.0 5.5 .3 23.8 Mebane 140 . . . . . . . . . . . . . .. 55.9 20.8 2.8 .4 24.0 CA 122 . . . . . . . . . . . . . . . . . . .. 64 2 23.5 2.4 .4 26.3 CA89A . . . . . . . . . . . . . . . . . . .. 50 0 253 3.5 .2 29.0 i Average . . . . . . . . . . . . . . . . . .. 56.5 22.1 3.6 0.3 26.0 ' i l Mid-season harvest Deltapine 14 . . . . . . . . . . . . . . . 63.8 22.6 3.3 5 26.4 Stoneville 2B . . . . . . . . . . . . . . . 50.0 18.4 4.0 4 22 8 Mebanel40................ 62.7 20.2 3.3 3 238 CA 122 . . . . . . . . . . . . . . . . . . .. 66.2 22.8 2.2 4 25 4 CA89A . . . . . . . . . . . . . . . . . . .. 50.0 21.7 3.7 3 257 I Average . . . . . . . . . . . . . . . . . .. 58.5 21.1 3.3 0.4 24 8 Percent change from early harvest . . . . . . . . . . . . . . .. +3.5 —4.7 —-9.1 +3.3 —4.8 Late harvest i Deltapine 14 . . . . . . . . . . . . . . . 73.3 25.8 2.7 3 28.8 Stoneville 2B . . . . . . . . . . . . . .. 50.0 18.2 2.5 4 21 . l Mebane 140 . . . . . . . . . . . . . . .. 44.8 15.6 1.9 4 17.9 CA122 . . . . . . . . . . . . . . . . . . .. 53.6 19.4 2.4 4 22.2 CA89A . . . . . . . . . . . . . . . . . . .. 50 0 19.5 1.7 2 21.4 Average . . . . . . . . . . . . . . . . . .. 54.3 19.7 2.3 0.3 22.3 Percent change from early harvest . . . . . . . . . . . . . . .. —4.0 —12.2 —56.5 0.0 ‘ —l6.6 Percent change from mid- season harvest . . . . . . . . . —7. 7 —7. 1 ~43 . 5 ——33 . 3 —ll . 2 . _ 1 Foreign matter removed by foreign Variety Original ~~ matter Percent of sample Extractor Cleaner Gin removed original (lbs.) (lbs.) (lbs.) (lbs.) (lbs.) sample Early harvest Deltapine 14 . . . . . . . . . . . . . .. 37.4 9.6 2.2 .3 12.1 32.4 Stoneville 2B . . . . . . . . . . . . . .. 39. 7 9.7 3.0 .4 13.1 33.0 ' Mebane140 . . . . . . . . . . . . . .. 37.2 9.1 2.3 .3 11.7 31.4 CA 122 . . . . . . . . . . . . . . . . . . .. 34.7 7.7 1.7 .2 9.6 27.7 CA89A . . . . . . . . . . . . . . . . . . .. 36.8 7.0 1.5 .3 8.8 23.9 Northern Star . . . . . . . . . . . . .. 38.8 8.8 2.7 .3 11.8 30.4 Paymaster . . . . . . . . . . . . . . . .. 36.4 9.7 2.4 .4 12.5 34.3 >Hl-Bl'6d . . . . . . . . . . . . . . . . . .. 39.0 8.6 2.0 .3 10.9 28.0 »StormproffNo.1............ 36.9 7.0 1.8 .4 9.2 24.9 Stormmaster . . . . . . _ . . . . . . .. 40.2 5.8 1.6 .6 8.9 19.9 Macha Early . . . . . . . . . . . . . .. 35.8 6.4 1.6 .5 8.5 23.7 Average . . . . . . . . . . . . _ . . _ _ 31.5 l s.1 l 2.1 0.4 i 10.6 l 28.2 Mid-season harvest Deltapine 14 . . . . . . . . . . . . . .. 41.6 12.3 2.7 .4 15.4 37.0 Stoneville 2B . . . . . . . . . . . . . .. 32.7 11.5 2.4 .2 14.1 43.1 _ Mebane 140 . . . . . . . . . . . . . . .. 37.8 12.4 2.0 .3 14.7 38.9 CA 122 . . . . . . . . . . . . . . . . . . .. 44 4 10.1 1.5 .4 12.0 27.0 CA89A . . . . . . . . . . . . . . . . . . .. 43.1 10.9 1.5 .3 12.7 29.5 Northern Star . . . . . . . . . . . . . . 38.5 8.7 2.2 .4 11.3 29._4 Paymaster . . . . . . . . . . . . . . . .. 35.6 10.8 2.0 .2 13.0 36.5 Hi-Bred . . . . . . . . . . . . . . . . . .. 34.6 8.8 1.9 .3 11.0 31.8 ‘StormproofNmI . . . . . . . . . ._ 44.3 9.0 1.8 .4 11.2 25.3 Stormmaster . . . . . . . . . . . . . .. 41.8 7.5 1.2 .5 9.2 22.0 p Macha Early . . . . . . . . . . . . . .. 45.4 8.0 1.4 .5 9.9 21.8 Average . . . . . . . . . . . . . . . . . .. 40.0 i 10.0 1.9 i 0.3 12.2 31.1 Percent change from early ‘ harvest . . . . . . . . . . . . . . . . . . . . . . . . .. +23.5 —10.5 —33.3 +15.1 +10.3 Late harvest Deltapine 14 . . . . . . . . . . . . . .. 40.9 13.9 2.8 .2 16.9 41.3 Stoneville 2B . . . . . . . . . . . . . .. 32.8 12.8 2.8 .2 15.8 48.2 Mebane140................ 41.8 13.2 2.2 .2 15.6 37.3 CA 122 . . . . . . . . . . . . . . . . . . .. 43.7 10.8 1.7 .4 12.9 29.5 CA89A . . . . . . . . . . . . . . . . . . .. 43.7 11.9 1.8 .3 14.0 32.0 Northern Star . . . . . . . . . . . . .. 40.5 11.9 2.6 .2 14.7 36.3 Payrnaster . . . . . . . . . . . . . . . .. 34.2 10.5 2.6 .2 13.3 38.9 Hi-Bred . . . . . . . . . . . . . . . . . .. 34.6 11.4 2.4 .2_ 14.0 40.5 Stormproof No. 1 . . . . . . . . . .. 37.8 8.9 2.0 ,4 11.3 29.9 Stormmaster . . . . . . . . . . . . . .. 44.2 8.2 1.7 .4 10.3 23.3 Macha Early . . . . . . . . . . . . . .. 40.4 7.5 1.8 .4 9.7 24.0 Average . . . . . . . . . . . . . . . 39.5 11.0 2.2 .3 13.5 34.3 Percent change from early harvest . . . . . . . . . . . . . . . . . . . . . . . . . . +35.8 +4.8 --33.3 +27.4 +22.7 Percent change from mid- season harvest . . . . . . . . . . . . . . . . . .. +10.0 +15.8 0.0 +10.7 +11.2 THE CLEANING OF MECHANICALLY HARVESTED COTTON 29 As explained above, this is attributed to the cotton plants being limber and tough at the early harvest and dry and brittle at the two later harvests. Table 12 shows that most of the foreign matter was removed in the extracting process. h Table 12. Average weight of original sample and foreign matter removed by the extractor, cleaner and gin from cotton machine-stripped at Lub- bock with No. 15 machine, 1946-48. l Total 30 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Lubbock; N0. 16 Machine. Tables 12 and 13 show that t average Weight of the sample from the No. 16 machine ran tf from 5.1 to 9.5 pounds less than from the No. 15 machi’ Consequently, comparisons are made 0n the percentage of .6 total foreign matter removed from the original samples. I Table 13. Average weight of original sample and foreign matter removl. extractor, cleaner and gin from machine-strip with N0. 16 machine, 1946-47 ped- cotton at Lu Total _ Foreign matter removed by foreign Variety Original matter Pere sample Extractor Cleaner Gin removed . ~ (lbs.) (lbs.) (lbs.) (lbs.) (lbs.) s: " Early harvest Deltapine 14 . . . . . . . . . . . . . .. 30.5 3.3 2.1 .2 5.5 Stoneville 2B..... 30.2 2.4 1.9 .2 4.5 Mebane140..... 30.1 1.6 1.8 .1 3.5 CA 122 . . . . . . .. 30.0 2.8 1.4 .3 4.5 CA 89A . . . . . . .. 30.0 2.5 1.3 .3 4.1 Northern Star.. 30.2 3.1 2.8 .2 6.1 Paymaster . . . . . . . . . . . . . . . .. 30.5 3.4 2.3 .2 6.0 Hi-Bred . . . . . . . . . . . 30.4 1.9 1.5 .3 3.7 Stormproof No. 1 . . . . . . . . . .. 30.4 3.3 1.5 .3 5.1 Stormmaster . . . . . . . . . . . . . .. 31.1 2.3 1.2 .4 3.9 Macha Early . . . . . . . . . . . . . .. 30.6 3.5 1.4 .2 5.2‘ Average . . . . . . . . . . . . . . . . . .. 30.4 2.7 1.8 0.2 4.7 Mid-season harvest Deltapine14 . . . . . . . . . . . . . .. 35.8 6.4 2.1 .3 8.8 Stoneville 2B . . . . . . . . . . . . . .. 30.0 4.2 2.2 .3 6.7 Mebane 140 . . . . . . . . . . . . . .. 33.5 4.5 2.2 .2 6.9 CA 122 . . . . . . . . . . . . . . . . . . .. 33.5 4.8 1.8 .4 7.0 CA89A . . . . . . . . . . . . . . . . . . .. 42.8 6.8 1.9 .2 8.9 Northern Star . . . . . . . . . . . . .. 33.2 4. 0 1. 6 .4 6.0 Paymaster....... . . . . . . . . .. 32.0 3.6 1.4 .4 5.5 Hi-Bred . . . . . . . . . . . . . . . . . .. 32.6 3.9 1.6 .4 5.9 Stormproof No. 1 . . . . . . . . . . . 35.6 4.8 1.3 .4 6.5 Stormmaster . . . . . . . . . . . . . . . 39.2 3.5 1 . 2 .5 5.1 Macha Early . . . . . . . . . . . . . .. 36.2 4.5 1.3 .6 6.4 Average . . . . . . . . . . . . . . . . . .. 34.9 4.6 1.7 0.4 6.7 Percent change from early ' harvest . . . . . . . . . . . . . . . . . . . . . . . . .. +70.4 —~5. 9 +l00.0 +42.6 + -J Late harvest Deltapine 14 . . . . . . . . . . . . . .. 31.2 4.8 1.9 .2 6.9 Stoneville 2B . . . . . . . . . . . . . .. 16.9 1.5 1.5 .1 3.1 Mebane 140 . . . . . . . . . . . . . . .. 32.0 3.3 1.7 .2 5.2 CA 122 . . . . . . . . . . . . . . . . . . .. 33.0 4.5 1.4 .2 6.1 CA 89A . . . . . . . . . . . . . . . . . . .. 32.9 5.0 1.4 .3 6.7 Northern Star . . . . . . . . . . . . . . 32. 9 4.2 .6 .2 5.0 Paymaster . . . . . . . . . . . . . . . .. 28.3 4.0 .5 .1 4.6 Hi-Bred . . . . . . . . . . . . . . . . . .. 30.0 3.5 1.4 .2 5.1 Stormproof No. 1 . . . . . . . . . .. 31.0 3.6 1.2 .3 5.2 Stormmaster . . . . . . . . . . . . . . . 30.2 2.9 1.2 .4 4.5 Macha Early . . . . . . . . . . . . . .. 32.1 4.0 1.3 .4 5.7 . Average . . . . . . . . . . . . . . . . . .. 30.0 4.0 1.3 0.2 5.3 P Percent change from early , ~ ' harvest . . . . . . . . . . . . . . . . . . . . . . . . .. +48.2 —-38.5 0.0 +12 8 + Percent change from mid- season harvest. . . . . . . . . —.—l5-0 —30-8 —100-0 —26-4 THE CLEANING OF MECHANICALLY HARVESTED COTTON 31 average percentages of foreign matter removed by the N0. 16 machine for the three harvests were 15.6, 19.2 and 17.5, re- spectively. Smaller amounts of foreign matter were removed from the No. 16 machine stripped and extracted cotton than from the No. 15 stripped cotton not extracted in the field. The differences in the average percentages of foreign matter for the No. 15 and 16 machines for the three harvests were 12.6, 11.9 and 17.1, respectively. The rate of increase in the total foreign matter removed was greater between the mid-season and early harvests than be- tween the mid-season and late harvests. The general trend in increased amounts of foreign matter removed for the late har- vest is similar for both the No. 15 and 16 machines. Foreign Matter Removed in Spinning Tests College Station: N0. 15 Machine. The first column in Table 14 shows: the percentage of foreign matter removed from lint samples of five varieties of machine-stripped cotton at College Station. There was no apparent significant difference in the average foreign matter removed from them for the three har- vests, as the percentages were 20.4, 21.9 and 21.6, respectively. The percentages of foreign matter removed from the differ- ent varieties harvested at early, mid-season and late were not consistent. The highest percentage of foreign matter, 23.8, was removed from Stoneville 2B at the early harvest. The highest percentages of foreign matter removed from any variety for the mid-season and late harvests were 23.8 and 24.0, respec- tively, from CA 122, a stormproof variety. The foreign matter removed from lint samples of Mebane 140 averaged the lowest for all three harvests. This variety has good cleaning qualities as it gives up foreign matter readily. Tables 14 and 15 show that considerably higher percentages of foreign matter were removed by the picker and cards in the spinning tests from cotton machine-stripped at College Station than at Lubbock. Tables 2, 3, 5, 6, 11 and 12 show that larger amounts of foreign matter were removed by the extractor and cleaner from cottons stripped with the No. 15 machine at Col- lege Station than at Lubbock. Lubbock: N0. 15 Machine. The first column of Table 15 shows the percentages of foreign matter removed by the picker and cards in spinning tests of lint samples from 11 varieties of machine-stripped cotton at Lubbock at early, mid-season and late harvests. The average percentages of foreign matter removed from all varieties at the three harvests were 16.9, 18.9 and 17.2, respectively. Higher percentages were removed from cottons harvested at mid-season than at the early and late har- vests. Table 6 shows that lower percentages of foreign matter 32 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION were removed by the cleaner from cottons stripped at mid-f season than from the early and late-harvested cotton. This may ' be the cause of higher percentages of foreign matter being removed by the picker and cards in the spinning tests. '7 Table 15 shows that the Mebane 140 and Hi-Bred varieties, which have a short and coarse fiber, were consistently lower i in the amounts of ‘foreign matter removed in the spinning tests. Table 15 also shows that higher average percentages of foreign matter were removed from the stormproof varieties CA 122, ;_ CA -89A, Stormproof No. 1, Stormmaster and Macha Early than from the normal boll varieties. These differences can be largely attributed to the more difiicult extracting qualities of Z the stormproof varieties and the good cleaning qualities of }f_ Mebane 140 and Hi-Bred. 1 Table 14. Average waste removed in spinning tests, the nep-s, strength and A appearance of 22 yarn, and the maturity of the fiber in cotton machine-stripped with N0. 15 machine at early, mid-season and i? late harvests at College Station, 1946-48 Percent of waste _ Variety removed 22 yarn Percent »_ by picker strength, Neps in card Appearance of fiber j and cards lbs. webl of 22 yarn maturityj Early harvest Deltapine 14 . . . . . . . . . . . . . . 20.8 103.1 30 h? C + 71 Stoneville 2B . . . . . . . . . . . . . 23. 8 102.4 46 vh3 C 66 Mebane 140 . . . . . . . . . . . . . . 18.1 87.8 17 av4 B 74 CA 122 . . . . . . . . . . . . . . . . .. 18.8 106.7 22 av C + 72 CA 89A . . . . . . . . . . . . . . . . .. 20.5 98.7 37h C+ 68 Average . . . . . . . . . . . . . . . . . 20.4 99. 7 30 h C + 70 Mid-season harvest Deltapine l4 . . . . . . . . . . . . . 22. l 100.0 23 av C + 72 Stoneville 2B . . . . . . . . . . . . . 22.8 97.2 44 vh C 65 Mebane 140 . . . . . . . . . . . . . . 20.0 82.5 15 l5 B 71 _ CA 122 . . . . . . . . . . . . . . . . .. 23.8 98.3 30 h B 79 CA 89A . . . . . . . . . . . . . . . . .. 20.7 99.4 36h C+ 68 Average . . . . . . . . . . . . . . . . . 21.9 95. 6 30 h C + 71 t h l‘ early Perch2rvgsl‘.n.gfi.i.?fn...... +8.4 —4.3 .0 . . . . . . . . . . .. +1.4 Late harvest n Dlt ' e14 . . . . . . . . . . . .. 22.9 98.7 23av C+ Sthnzlvlilile 2B . . . . . . . . . . . . . 21.6 93.0 24 av C + Mebane 140 . . . . . . . . . . . . . . 21.3 79. 7 20 av B CA 122 . . . . . . . . . . . . . . . . .. 24.0 96.4 26av C+ CA 89A . . . . . . . . . . . . . . . .. 1s.0 101.7 28h C+ Average . . . . . . . . . . . . . . . . . 21 . 6 93.9 24 av C + Percent change from early harvest . . . . . . . . . . . . . . +5- 9 -5-2 —25-9 - - - - - - - - - - - - Percent change from mid- ' season harvest . . . . . . . . —l . 4 ——l . 8 —25. 0 . . . . . . . . . . . . . . . . . . . . f . lPgr square 100 inches. Zhigh. 3very high. 4average. 510w. THE CLEANING OF MECHANICALLY HARVESTED COTTON Lubbock‘: N0. 16 Zlfachine. 33 Five varieties of varying fiber and storm resistance qualities were selected from the 11 varieties harvested for the spinning and fiber tests. The first column of Table 16 shows that the foreign matter removed from cottons Table 15. Average waste removed in spinning tests, the neps, strength and appearance of 22 yarn and the maturity of the fiber in cotton machine-stripped with N0. 15 machine at early, mid-season and late harvests at Lubbock, 1946-48 Percent of waste Variety removed 22 yarn Percent by picker strengt Neps in card Appearance of fiber and cards lbs. web] of 22 yarn maturity Early harvest Deltapine 14 . . . . . . . . . . . .. 14.7 105.23 32 hfi C + 76 Stoneville 2B . . . . . . . . . . . . . 16. 6 104. 53 33 h C + 72 Mebane 140 . . . . . . . . . . . . .. 12.9 89.43 1517 B 75 CA 122 . . . . . . . . . . . . . . . . .. 19.1 98.53 14] B+ 77 CA 89A . . . . . . . . . . . . . . . . .. 19.1 96.03 22 av3 B 72 Northern Star . . . . . . . . . . .. 16.7 110.84 11 l C + 71 Paymaster . . . . . . . . . . . . . . . 14. 5 103 .44 19 av C + 78 Hi-Bred . . . . . . . . . . . . . . . . . 14.9 85. 34 24 av B 82 Stormproof No. 1. . 16.4 94.84 17 av 13+ 73 Stormmaster . . . . . . . . . . . . . 21.1 101 . 54 33 h C + 72 Macha Early . . . . . . . . . . . . . 20.2 105.94 27 av C + 72 Average................. 16.9 100.0 22av B— 74 Mid-season harvest Deltapine 14 . . . . . . . . . . . . . 17.0 100.04 33 h C 73 Stoneville 2B . . . . . . . . . . . . . 19.4 97.23 28 h C + _ 72 Mebane 140 . . . . . . . . . . . . .. 13.3 83.74 18 av B 78 CA 122 . . . . . . . . . . . . . . . . .. 19.6 98.32 34 h B 68 CA 89A . . . . . . . . . . . . . . . . .. 17.4 100.54 28h C+ 70 Northern Star . . . . . . . . . . . . 19. 6 109.24 17 av C + 79 Paymaster . . . . . . . . . . . . . . . 18. 4 100. 24 36 h C 76 Hi-Bred . . . . . . . . . . . . . . . .. 15.0 88.74 151 C+ 80 Stormproof No. 1 . . . . . . . . . 18.4 97.84 25 av B 70 Stormmaster . . . . . . . . . . . . . 24.9 101.54 21 av C + 70 Macha Early . . . . . . . . . . . .. 25.0 101.94 22 av C + 74 Average . . . . . . . . . . . . . . . . . 1s. 9 \ as. 1 25 av c + 14 Percent change from early ‘ harvest . . . . . . . . . . . . .. +l1.8 —1.8 +13.6 . . . . . . . . . . .. 0.0 Late harvest Deltapine 14 . . . . . . . . . . . .. 15.5 97.24 36 h C 72 Stoneville 2B . . . . . . . . . . . . . 18. 7 96.43 34 h C 70 Mebane 140 . . . . . . . . . . . . . . 13.5 85. 93 141 B 77 CA 122 . . . . . . . . . . . . . . . . . . 18.1 97.02 23 av B 68 CA 89A . . . . . . . . . . . . . . . . . . 17.7 101.14 28 av C+ 70 Northern Star . . . . . . . . .. 17. 7 109.15 21 av C + 60 Paymaster . . . . . . . . . . . . . . . 18.5 97.85 40 h C 74 Hi-Bred . . . . . . . . . . . . . . . . . 15.3 88. 85 29 h C + 74 Stormproof No. 1 . . . . . . . . . 14.5 97.95 31 h B 68 Stormmaster . . . . . . . . . . . . . 20.5 107.35 l9 av B 69 Macha Early . . . . . . . . . . . . . 19.6 103.45 24 av C —|— 69 Average . . . . . . . . . . . . . . . . . 17.2 98. 4 27 av _C + 70 Percent change from early harvest . . . . . . . . . . . . .. +1.8 —l.l +22.7 . . . . . . . . . . .. +5.7 Percent change from mid- season harvest . . . . . . . ——9.9 +0.7 +8.0 . . . . . . . . . . .. +5 7 lPer 100 square inches. 31947 only 51948 only 7Low 21946 only 41946-1947 5High sAverage l i 34 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION harvested at Lubbock with the N0. 16 machine followed t same trends as shown for the No. 15 machine (Table 15 . Higher percentages were removed from cotton harvested mid-season than at the early and late harvests. The lowest percentage of foreign matter removed from a ” one variety for all three harvest dates was from Mebane 14 The stormproof varieties CA 122 and CA 89A gave up highg percentages of foreign matter than did the normal boll vari; ties, Deltapine 14, Stoneville 2B and Mebane 140. The causl of these differences are apparently the same as given for t differences in the foreign matter removed for the cottons ha . vested with the No. 15 machine. All the cotton harvested with the No. 16 machine gave u‘ lo-Wer percentages of foreign matter in the spinning tests f Table 16. Average waste removed in spinning tests, the nepsfand stren and appearance of 22 yarn in cotton machine-stripped with N 16 machine at early, mid-season and late harvests at Lubb 1946-47 Percent of waste Variety removed 22 yarn by picker strength, Neps in Appearanc and cards lbs. card webl of 22 yar Early harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . . .. 12.7 101.9 34 h? C+ Stoneville 2B . . . . . . . . . . . . . . . . . . . . . 12. 0 102.2 27 h C-l- Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 10.6 86.4 1413 B CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 18.9 101.0 27h C+ CA 89A . . . . . . . . . . . . . . . . . . . . . . . . . . 17.8 99.8 21 av4 B Average . . . . . . . . . . . . . . . . . . . . . . . . . . 14.4 98.3 25 av C + Mid-season harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . . . . 16.0 99.2 22 av B Stoneville 2B . . . . . . . . . . . . . . . . . . . . . 17.6 100.1 42 vh5 C Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 13.3 85.6 l4 h B CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 16.6 96.8 31h C+ CA 89A . . . . . . . . . . . . . . . . . . . . . . . . . . 16 9 100.0 39 h C Average . . . . . . . . . . . . . . . . . . . . . . . . .. 16.1 96.3 30 h C+ Percent change from early harvest. . +1l.8 —-2 1 +20.0 . . . . . . . . . . . .. Late harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . . . . 14.8 98. 5 24 av C + Stoneville 2B . . . . . . . . . . . . . . . . . . . . . 15.2 96. 7 36 h C + Mebane 140 . . . . . . . . . _ . . . . . . . . . . . .. 12.8 85.6 161 B CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 15 5 98.7 34 h C CA 89A . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1 102. 1 26 av B _ Average . . . . . . ... . . . . . . . . . . . . . . . .. 15.1 96.3 27 av C+ Percent change from early harvest. . +4. 9 -2.1 +8.0 . . . . . . . . . . . . Percent change from mid-season harvest . . . . . . . . . . . . . . . . . . . . . . . ——6. 6 .0 -—-11.1 lPer 100 square inches. ?High. 3Low. 4Average. 5Very high. THE CLEANING OF MECHANICALLY HARVESTED COTTON 35 all three harvests than did the cottons harvested with the N0. 15 machine (Tables 15 and 16). There was no difference for Mebane 140 at the mid-season harvest. These differences indicate clearly that where cotton is stripped and extracted before the foreign matter, particularly the fine trash, is worked into the fiber, that higher percentages of the foreign matter are removed in the extracting process. GRADE OF MACHINE-STRIPPED COTTON The grade of the machine-stripped cottons for each variety at the three harvests for College Station and Lubbock is shown numerically in Tables 8, 9 and 10. College Station: No. 15 Machine. Table 8 shows the numer- ical grade for the cottons stripped at College Station early, mid- season and late. There was little difference in the average grade for the varieties harvested at early, mid-season and late dates, 7.8, 8.2 and 8.2, respectively. This is quite a low grade as 8.0 is strict good ordinary. The early-harvested cottons aver- aged .4 higher, or almost one-half grade, than the mid-season and late-harvested cottons. CA 122, a stormproof strain, gave a grade from one-half to one grade higher than the average for all three harvest dates, while CA 89A, another stormproof strain, averaged one grade lower. This is attributed to better response to defoliation of the CA 122 than the CA 89A, and that there was less green leaf trash in the CA 122 cotton (Table 2). Lubbock: No. 15 Machine. Table 9 shows the numerical av- erage grade for the early harvested cottons was 7.6, (SGO-k), while the mid-season harvest averaged 9.3, (GO—), and the late harvest averaged 8.6, (GO-k). At the early harvest, Hi-Bred gave the highest grade, 6.5 (LM-lr) , while Stoneville 2B gave the lowest grade of 9.0 (GO). This is a difference of 2.5 grades between the lowest and high- est grade. Hi-Bred is a good cleaning cotton while Stoneville 2B has poor cleaning qualities. At the mid-season and late harvests, CA 122 graded 8.0 (SGO) and 7.5 (SGO-k), respectively, the highest grade of all the varieties for these dates. Both Hi-Bred and Mebane 140 gave grades slightly higher than the average for mid-season and late harvests. Stoneville 2B, Deltapine 14, Northern Star arid bBaygmaster gave grades, generally, lower than the average a e . Lubbock: N0. 16 Machine. Table 10 shows that the average grade for each harvest with the N0. 16 machine was one to two grades higher than the cotto-n harvested with the No. 15 HIM"; -‘ “aie-née~_<_~v=-.c<. ‘ ‘ ‘ ‘ ‘ 36 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION machine. The average grade, where the cotton was harves early, mid-season and late with the No. 16 machine, was 5;, (SLM), 7.2 (LM) and 7.7 (SGO+), respectively, as compare with 7.6 (SGO+), 9.3 (GO—) and 8.6 (GO+), respective] when harvested with the N0. 15 machine. Each variety h vested with the No. 16 machine early and mid-season al" graded higher than when harvested with-the No. 15 machi (Tables 9 and 10). When harvested with the No. 15 machi" at mid-season, 6 0f the 11 varieties gave BG (below grade grades, but when harvested with the No. 16 machine only on variety was below grade. At the late harvest, the cotton fr _ three varieties graded BG when harvested with the No. P machine, while only one gave BG cotton when harvested wi the No. 16 machine. ' “5 The grade differences show that the use of the field extract; resulted in higher grades at the early and mid-season harves ~ and. gave equal 0r better grades at the late harvest. The grades shown in Table 10 indicate that when the ha . vest is late the foreign matter is more difficult to remove an; the grade of the lint is lowered. STAPLE LENGTH OF MACHINE-STRIPPED COTTON Tables 8, 9 and 10 do not show any indication of injury 4 the staple, or that the staple is significantly affected by delayi 1 the harvest until late in the season. The average staple len for each harvest is approximately the same. As expected, howf ever, the average staple length at College Station for the sam varieties is slightly longer than at Lubbock. l; STRENGTH OF 22 YARN FROM MACHINE-STRIPPED COTTON The lint samples were spun into 22 yarns after the foreign; matter was removed by the picker and cards. Yarns were spunggi from samples for each of the 11 varieties harvested early, mide seas-on and late with the No. 15 machine at Lubbock. Wher‘? the cotton was harvested at Lubbock with the No. 16 machine, the same five varieties harvested at College Station with the? No. 15 machine were selected for the spinning tests. = College Station: No. 15 Malchine. The second column in? Table 14 shows the strength of 22 yarn spun from five varieties? harvested early, mid-season and late at College Station. The“; strength of the yarn for the early-harvested cotton was highest? with an average of 99.7 pounds for the five varieties. The} co-tton harvested in mid-season produced a yarn having a;l~; strength of 95.6 pounds, while the late-harvested cotton pro- duced a yarn having a strength of 93.9 pounds. Thus, the? strength of the yarn decreased for the late-harvested cotton. [ THE CLEANING OF MECHANIGALLY HARVESTED COTTON 37 This trend is shown for Deltapine 14, Stoneville 2B, Mebane 140 and CA 122 but not for CA 89A as the yarn, for this variety became increasingly stronger for the mid-season and late harvests, or 98.7, 99.4 and 101.7 pounds, respectively. Deltapine had the highest average yarn strength, 103.1, 100.0 and 98.7 pounds, respectively, for the three harvests, while the short-staple Mebane 140 had the weakest yarn for each of the three harvests, 87.8, 82.5 and 79.7 pounds, respectively (Tables 8 and 14). The strain CA 89A had the highest yarn strength of any variety at the late harvest. Lubbock: N0. 15 Machine. Table 15 shows that the average yarn strength for the 11 varieties harvested with the No. 15 machine at Lubbock was the lowest for the mid-season harvest. The late-harvested cotton produced a yarn that averaged slight- ly stronger than the mid-season cotton, but. slightly weaker than the early harvested cotton. The average yarn strength for the three harvests were 100.0, 98.1 and 98.4 pounds, re- spectively. As at College Station, the trend appeared to be that yarn from normal boll varieties became weaker, but the yarn from some of the stormproof varieties became stronger as the sea- son advanced (Table 15). The long staple cottons produced a stronger yarn than the short staple cottons (Tables 9 and 15). For example, Delta- pine 14 had a staple length of 29, 32 and 29 thirty-seconds. of i an inch, respectively, for early, mid-season and late harvests, while Hi-Bred had a staple length of 26 for all three harvests (Table 9). The yarn strength for Deltapine 14 was 105.2, 100.0 and 97.2 pounds, respectively, while the yarn strength for Hi- Bred was 85.3, 88.7 and 88.8 pounds, respectively, or an average difference of 13.2 pounds (Table 15). When the averages for all 11 varieties are considered, there is a greater difference in the yarn strength between varieties than between the harvest dates. Lubbock: N0. 16 Machine. The yarn strength data for the five varieties listed in Table 16 and the yarn strength data for these same varieties in Table 15 show that there is little dif- ference in the average yarn strength where the cotton was harvested with the Nos. 15 and 16 machines. The cotton from both machines received the same treatment, with the exception that the field extractor of the No. 16 ma- chine removed almost 50 percent of the to-tal foreign matter in the field. 38 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION APPEARANCE OF 22 YARN FROM MACHINE-STRIPPED COTTON Y The fourth columns of Tables 14, 15 and 16 show the classi- l; fication for the appearance of the 22 yarn. The grade 0f the yarn appearance is in letters, with “A” being the best and the descending letters of the alphabet being lower in grade. College Station: N0. 15 Machine. Table 14 shows that the average grade of yarn appearance for all three harvests was C—|—. The yarn spun from Mebane 140 cotton graded B for all _, three harvests, while Deltapine 14 and CA 89A graded C-|-.‘ » The yarn grade for Stoneville 2B and CA 122 ranged from C to B for the three harvests. ~ -: Lubbock: No. 15 Machine. The average grade for all Var-f. rieties harvested with the No. 15 machine was B— at the early l harvest and C-l- forthe mid-season and late harvests. The yarn g appearance for Mebane 140, CA 122 and Stormproof No. 1 graded B for all three harvests. Northern Star and Macha Early graded C+ for the three harvests. Hi-Bred‘ graded B at the early harvest and C-l- for the mid-season and late harvests. Lubbock: No. 16 Machine. The yarn appearance for the cottons harvested with the N0-. 16 machine averaged C-l- for all three harvests. The average grade of yarn appearance for the same five varieties harvested with the No. 15 machine did not differ significantly from the average grade shown for the No. 16 machine. “é r ._ .=~_ (‘I The yarn from Mebane 140 graded B for all three harvests, - r while the yarn grade for the other varieties ranged from C to B with no definite trend between the harvests. NEPS IN THE CARD WEB OF MACHINE-STRIPPED » all; COTTON The third columns of Tables 14, 15 and 16 show the average 5; nep classification in the card web. The neps are classed as low (1 to 15), average (16 to 25), high (26 to 40) and very high (41 and above). College Station: No. 15 Machine. The average neps for all varieties was 30 for the early and mid-season harvests and 24 for the late harvest (Table 14). Mebane 140 had the least neps, while Stoneville 2B had the highest quantity of neps for all ‘gl. three harvests. Lubbock: No. 15 Machine. Table 15 shows that the average neps in the card web for al varieties was 22, 25 and 27, re- spectively, for the early, mid-season and late harvests. The neps were consistently loW in the card web for Mebane 140 A and Northern Star and rather consistently high for Deltapine '1: THE CLEANING OF MECHANICALLY HARVESTED COTTON 39 14 and Stoneville 2B. The quantity of neps for the other va- rieties fluctuated and did not follow a definite trend in the harvest dates. Lubbock: N0. 16 Machine. Table 16 shows a similar trend for the same varieties as Table 15. That is, the neps in the card web for Mebane 140 are consistently low While the neps in Deltapine 14 and Stoneville 2B are consistently high for all three harvests. MATURITY OF FIBER IN MACHINE-STRIPPED COTTON The fifth co-lumns of Tables 14 and 15 show the fiber ma- turity for each variety harvested early, mid-season and late at College Station and Lubbock. The percentage of mature fibers was slightly higher at Lub- bock than at College Station. There was not enough difference between the average maturity of the fibers for all varieties for the three harvests to affect yarn strength and appearance significantly. At College Station, the average fiber maturity was 70 per- cent at the early and late harvests and 71 percent at the mid- season harvest (Table 14). This table shows that Deltapine 14, Mebane 140 and CA 122 had the highest percentage of mature fiber at all three harvests, while Stoneville 2B and CA 89A had the lowest percentages. At Lubbock, the average fiber maturity for all 11 varieties was 74 percent at the early and mid-season harvests and 70 percent at the late harvest. r Hi-Bred had the highest percentage of mature fibers at the early and mid-season harvests, 82 and 80, respectively, but dropped to 74 percent at the late harvest. The percentage of fiber maturity was fairly consistent for most varieties at each of the three harvests and had little sig- nificant effect on the yarn strength, appearance and neps. FOREIGN MATTER REMOVED FROM MACHINE-PICKED COTTON The machine-picked cotton was harvested with a regular com- mercial cotton picking machine (Figure 3). The dates of har- vest were approximately the same dates as for the machine- stripped cotton. Samples of machine-picked cotton were not obtained for Lubbock as a mechanical picker was not available at that location. 40 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Foreign Matter Removed by the Cleaner The samples of machine-picked cotto-n Were not run throu the extractor as they had few burs. Table 17 shows the u.’ centages of three kinds 0f foreign matter removed from m", chine-picked samples. There were slight increases, for the mi, season and late harvests, in the average amount of motes, bu ‘i and stems, 1.6, 1.7 and 2.1 percent, respectively. A hig average percentage of fine trash was removed from the fi varieties harvested at mid-season than at the early harve The lowest amount of fine trash was removed from the la ‘ harvested cotton. The average percentage of dirt and sand J creased consistently for the mid-season and late harvests, 4. 3.0 and 2.7 percent, respectively, for the three dates. Dirt p sand were the main types of foreign matter removed that i, fiuenced the total average percentages of 8.1, 7.9 and 7.2, i spectively, for the three harvests. Table 17. Average percentages of different kinds of foreign matter moved by the cleaner from varieties of cotton machine-pi .~ early, mid-season and late at College Station, 1947-48 , Total perc Variety Clean Motes, Fine Dirt Invisible forei I seed burs and trash and loss ma. . cotton stems sand remov Early harvest i t Deltapine 14 . . . . . . . . . . . . . . . . . . . .. 93.3 1.4 2.7 2.5 .1 Stoneville 2B . . _ . . . . . . . . . . . . . . . .. 91.0 1.2 1.8 5.4 , .6 Mebane 140 . . . . . . . . . . . . . . . . . . . .. 91.2 1.4 1.0 6.1 .3 CA 122 . . . . . . . . . . . . . . . . . . . . . . . . .. 92.1 2.2 2.6 2.5 .6 Average . . . . . . . . . . . . . . . . . . . . . . . .. 91.9 1.6 2.0 4.1 0.4 Mid-season harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . .. 92.0 1.8 2.6 3.0 .6 Stoneville 2B . . . . . . . . . . . . . . . . . . .. 91.6 1.6 2.6 3.4 .8 Mebane 140 . . . . . . . . . . . . . . . . . . . .. 92.2 1.6 2.8 3.0 .4 CA 122 . . . . . . . . . . . . . . . . . . . . . . . . .. 92.5 1.8 2.4 2.8 .5 Average . . . . . . . . . . . . . . . . . . . . . . . .. 92.1 1.7 2.6 3.0 0.6 Percent change from early harvest.. +.2 +6.2 +30.0 —36. 7 . . . . . . . . Late harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . .. 91.6 2.5 1.9 3.4 .6 Stoneville 2B . . . . . . . . . . . . . . . . . . .. 93.9 1 . 7 1.6 2.5 .3 Mebane140 . . . . . . . . . . . . . . . . . . . .. 93.3 1.6 1.2 3.5 .4 A122 . . . . . . . . . . . . . . . . . . . . . . . . .. 92.6 2.6 2.7 1.5 .6 Average . . . . . . . . . . . . . . . . . . . . . . . .. 92.8 2.1 1.9 2.7 0.5 Percent change from early harvest. +1. 0 +31 . 2 +5.3 ——5l . 8 . . . . . . . . Percent change from mid-season harvest . . . . . . . . . . . . . . . . . . . . . . +0.8 +23.g5 —36.8 ——ll . l . . . . . . . . THE CLEANING OF MECHANICALLY HARVESTED COTTON 41 The decrease in the amount of foreign matter removed, ap- parently, Was due to there being less dirt and sand collected in the cotton. At the early harvest, Deltapine 14 was picked be- fore rains had fallen on the open cotton, While Stoneville 2B and Mebane 140 were picked after the rain. Therefore, the amount of dirt and sand removed from Deltapine 14 was 2.5 percent, in comparison with 5.4 and 6.1, respectively, for Stone- ville 2B and Mebane 140. CA 122 contained less dirt and sand than Deltapine 14, Stone- ville 2B and Mebane 140 for all three harvests. On the other hand, the stormproof varieties had relatively high percentages of motes and burs, and fine trash. The data indicate that the amount of foliage and the condi- tion of the open cotton as influenced by rains will afiect the percentage of foreign matter collected in harvesting with the mechanical picker. ' l8 18. Average percentages of different kinds of foreign matter removed in gin- ning, the percentages of seed and lint, the grade and staple of cotton ma- chine-picked early, mid-season and late at College Station, 1947-48 Total Dirt foreign Variety Fine and Invisible matter trash sand loss loss Seed Lint Grade Staple Early harvest tapinel4 . . . . . . . . . . . . . .. .5 .2 .4 1.1 66.8 32.1 7.5 28 neville2B . . . . . . . . . . . . .. .5 .5 .1 1.1 63.4 35 5 7.0 30 bane 140 . . . . . . . . . . . . . .. .4 .2 .5 1.1 61.6 37.3 5.5 28 122 . . . . . . . . . . . . . . . . . . .. .5 .2 .6 1.3 64.7 34.0 6.5 29 erage . . . . . . . . . . . . . . . . . .. 0.5 0.3 0.4 1.2 64.1 34.7 6.6 28.8 Mid-season harvest tapine 14 . . . . . . . . . . . . . .. .5 .2 .2 .9 61.8 37.3 7.2 28 neville2B . . . . . . . . . . . . .. .4 .1 .4 .9 63.6 35.5 7.2 29 .bane140 . . . . . . . . . . . .. .4 .2 .2 .8 61.8 374 7.0 27 122 . . . . . . . . . . . . . . . . . . .. .6 .3 .7 1.6 64.3 34.1 7.0 28 erage . . . . . . . . . . . . . . . . . .. 0.5 0.2 0.3 1.0 62.9 36.1 7.1 28.0 l cent change from early harvest . . . . . . . . . . . . . . .. 0.0 —50.0 ——33.3 ——20.0 —l.9 +4.0 —7.6 . . . . . . .. Late harvest ltapine 14 . . . . . . . . . . . . . .. .6 .2 .5 1.3 63.0 35.7 7.5 28 oneville2B . . . . . . . . . . . . .. .4 .2 .5 1.1 67.8 31.1 7.5 28 ebane 140 . . . . . . . . . . . . . .. .5 .3 .6 1.4 61.3 37.3 7.0 26 . . . . . . . . . . . . . . . . . . . .. .5 .2 .6 1.3 64.8 33.9 7.0 28 erage . . . . . . . . . . . . . . . . . .. 0.5 0.2 0.6 1.3 64.2 34 5 7.2 27.5 - cent change from early harvest................ 0 0 —50 0 +501) +8.3 +0.2 —-0.6 —9.1 . _ . _ , , ,_ ercent change from mid- season harvest . . . . . . . .. 0.0 0.0 +l00.0 +30.0 +2.1 —5.0 —l.4 . . . . . . .. 42 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Foreign Matter Removed by Ginning Table 18 shows that the amount of fine trash averaged i same for the five varieties at each harvest date, 0.5 perce‘ The amount of dirt and sand averaged 0.1 percent more for t ; early harvest than for the mid-season and late harvests. y l total average amount of foreign matter, which included the '_ ; visible loss, was highest, 1.3 percent, for the late harvest and l § lowest, 1.0 percent, for the mid-season harvest. The difference} {a the amount of foreign matter removed from varieties is ~ ’ ’ small that no conclusion can be drawn from them. The cleani‘, . of the dirt and trash from the floor and experimental err l could well account for the small differences. ‘ Foreign Matter Removed in Spinning Tests The first column in Table 19 shows that the percentages foreign matter removed from the five varieties for the th i, Table 19. Average percentages of foreign matter removed in spinning tes neps, strength and appearance of 22 yarn, and the maturity w‘ fiber in cotton machine-picked early, mid-season and late at C\ Station, 1947-48 Percent of E foreign ; matter ; i‘ Variety removed by Per ‘ ‘ , picker and 22 yarn Neps of Appearance p 3 cards strength card webl of 22 yarn ma Early harvest a Deltapine 14 . . . . . . . . . . . . . . . . . . . . .. 15.8 105.8 24 av? C + . Z Stoneville 2B . . . . . . . . . . . . . . . . . . . . . 14.5 110. 8 20 av C + i Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 12.2 92.6 7 l3 B CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 13.3 113.4 lll B Average . . . . . . . . . . . . . . . . . . . . . . . . .. 14.0 105.6 16 I B- Mid-season harvest _' Deltapine 14 . . . . . . . . . . . . . . . . . . . . . . 14.2 102.2 22 av B 1 Stoneville 2B . . . . . . . . . . . . . . . . . . . .. 12. 7 106.8 28 h4 B Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 13.0 89.4 19 av B ‘ L i CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 16.9 107.0 151 B ‘ Average . . . . . . . . . . . . . . . . . . . . . . . . .. 14.2 101.4 21 av B 1’ Percent change from early harvest. . +1.4 —4. 1 +31 .2 . . . . . . . . . . ' ' Late harvest Deltapine 14 . . . . . . . . . . . . . . . . . . . . .. 14.1 101. 9 14 h C + 7 ; Stoneville 2B . . . . . . . . . . . . . . . . . . . . . 15.4 100. 4 16 a-v C + 6_ i Mebane 140 . . . . . . . . . . . . . . . . . . . . .. 13. 4 83.7 81 B 7 . CA 122 . . . . . . . . . . . . . . . . . . . . . . . . . .. 15.6 107.3 21 av B é Average . . . . . . . . . . . . . . . . . . . . . . . . .. 14.6 98.3 151 B- Percent change from early harvest.. . +4.3 ——7. 4 —6. 7 . . . . . . . . . . -—- I Percent change from mid-season harvest . . . . . . . . . . . . . . . . . . . . . . . +2. 8 —3.2 —40.0 . . . . . . . . . . lPer 100 square inches. 2Average. 3Low. 4High. THE CLEANING OF MECHANICALLY HARVESTED COTTON 43 {harvests were 14.0, 14.2 and 14.6, respectively. There was a slight increase in the foreign matter removed at the two later harvests. The increase, however, is s0 small that no conclusion can be drawn. The lowest percentage of foreign matter was removed from ‘ j Mebane 140 for the early and late harvests, while Stoneville _ 2B gave up the least amount at the mid-season harvest. CA 122 1 gave up the highest percentage at the early harvest. These differences may indicate the amount of foreign matter left in the seed cotton in cleaning and also that there is a dif- ference in the cleaning qualities of the varieties. GRADE OF MACHINE-PICKED COTTON Table 18 shows the numerical grade for four varieties of ~ machine-picked cotton at College Station. The average grades at the early, mid-season and late harvests were 6.6 (LM+), 7.1 (LM) and 7.2 (LM), respectively. ' The early-harvested cotton averaged about one-half grade higher than the cotton harvested at mid-season and late. There was only a slight difference in the average grade of the cottons at mid-season and late harvests. At the early harvest, Mebane 140 was one grade higher, 5.5 (SLM+) than the next best grade for CA 122, 6.5 (LM+). Deltapine 14 and Stoneville 2B gave grades of 7.5 (SGO+) and 7.0 (LM), which were one to two grades lo-wer than Me- bane 140 and CA 122. There was little difference in the grades for each of the varieties at the mid-season and late harvests (Table 18). APPEARANCE OF 22 YARN FROM MACHINE-PICKED COTTON The fourth column of Table 19 shows the appearance of 22 yarn spun from machine-picked cotton at College Station. The average grades of the yarns. for the early, mid-season and late harvests were B—, B and B—, respectively. Deltapine 14 and Stoneville 2B graded C-I» at the early and late harvests. There- fore, there were no significant differences in the appearance of the yarns for the varieties for the three harvest dates. The yarn from machine-picked cotton graded slightly higher than that from the machine-stripped cotton, or B— for the former and C—|— for the latter, for the early and late harvests (Table 14 and 19). _ tons shown in Table 8 is compared with the staple length the machine-picked cottons in Table 18, it is seen that i, 44 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION __ STAPLE LENGTH OF MACHINE-PICKED COTTON§ The average staple length of the machine-picked cotton vij came slightly shorter at the late harvest. This trend was i‘ ticeable for all varieties except Deltapine 14 which had _ same staple length for each of the three harvests (Table 18). l, difference in staple length is so slight that it cannot be co‘, sidered significant. When the average staple length of the machine-stripped co former are about one-thirty-second of an inch longer than latter, for all three harvests. This difference may be attribu to the extractor throwing out a high percentage of the ha knotty, partially-open bolls. Tables 14 and 19 show that the machine-picked cotton had slightly higher percentage of mature fibers at the early a '1 mid-season harvests than the machine-stripped cotton. Ther was no difference in the average maturity of the fibers for thf* two methods of harvest at the late harvest. - é? These data, therefore, are not conclusive enough to explain; these slight differences in staple length between machine-picked? and machine-stripped cottons. NEPS IN CARD WEB AND MATURITY OF FIBER IN MACHINE-PICKED COTTON The third and fifth columns in Table 19 show neps in the!‘ card web and the percentage of mature fibers in machine-j, picked cotton. The average neps per square inch of card webg was low for the early and late harvests and average for the}; mid-season harvest. The average percentage of mature fibers was 72, 75 and 70, respectively, for the early, midseason and late harvests. i As the number of neps and the percentage of mature fibers followed no definite trend, no conclusions can be drawn from these data. a ACKNOWLEDGMENTS The authors wish to express their appreciation to Deere andoi; I Company for the loan of the cotton strippers used at both g _ College Station and Lubbock; to the International Harvester-l; Company for picking the samples of machine-picked cotton ates College Station; and to the Cotton Testing Laboratory, Pro- duction and Marketing Administration, U. S. Department of Agriculture at College Station, for making the spinning and 1‘ fiber tests. 7 THE CLEANING OF MECHANICALLY HARVESTED COTTON 45 SUMMARY AND CONCLUSIONS Cotton was mechanically harvested with strippers at both College Station and Lubbock. The stripper at Lubbock was used with and without an extractor. A mechanical picker was used only at College Station. Cotton was harvested on dates considered early, mid-season and late for the location. The late harvest at College Station was usually made before the earliest harvest at Lubbock. Samples of the machine-stripped cotton were extracted. The foreign matter was removed and separated into four classes, burs, stems, fine trash, and dirt and sand. The percentage of each class was calculated against the weight of the original sample. The seed cotton from the extracting process was cleaned. The foreign matter was removed and separated into three classes, motes, burs and stems; fine trash; and dirt and sand. The percentage of each class was calculated against the weight of the seed cotton sample. The foreign matter was collected after ginning each sample and was separated into two classes, fine trash, and dirt and sand. The percentage of each class was calculated against the weight of the clean seed cotton. The foreign matter removed in the spinning tests was cal- culated against the weight of the lint samples. This sample did not always consist of all the lint ginned. Foreign matter from the machine-picked cotton was handled similar to the machine-stripped cotton. This cotton, of course, was not run through the extractor. At College Station, the early harvested stripped cotton con- tained more foreign matter than did cottons harvested in mid- season and late. This was due to poor defoliation at the early harvest. The average total percentages of foreign matter re- moved from five varieties by the extractor at College Station for the early, mid-season and late harvests were 39.4, 36.5 and 36.4, respectively. The average percentage of burs and stems remained fairly constant for the three harvests while the fine trash decreased and the dirt and sand increased as the harvest was deferred. At Lubbock, the average total percentages of foreign matter removed from 11 varieties where the cotton was harvested with the No. 15 stripper, which was no-t equipped with a field extrac- tor, were 21.4, 25.4 and 28.2, respectively, for early, mid-season and late harvests. The stems in the cotton stripped with the No. 15 machine increased 175 percent and the dirt and sand increased 209 percent from the early to the late harvest. The stormproof varieties, generally, gave up less total percentages of foreign matter than the normal boll varieties. 46 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION Where the No. 16 cotton stripper, equipped with a tractor- mounted field extractor, was used, the total foreign matter re- moved averaged less than half that removed from cotton stripped with the No. 15 machine. There was a 500 percent" increase in the amount of stems in the No. 16 machine-stripped cotton from the early to the late harvest. The results show that the amount of stems, dirt and sand, and total foreign matter removed from machine-stripped cot- ton increases greatly when the harvest is delayed until the‘ plants have become dry and brittle and the Wind has blown dirt and sand into the open, fluffy locks. Foreign matter removed by the cleaner from cotton stripped at College Station decreased at the later harvests, which had better defoliation. At Lubbock, in cotton harvested with the No. 15 machine, the average total percentages of foreign matter removed by the cleaner for the early, mid-season and late harvests were 7.0, 6.5 and 8.4, respectively. The late stripped cotton gave up 20 percent more foreign matter than did the early stripped cotton. The greatest increase in the kind of foreign matter removed by the cleaner from cottons stripped with the No. 15 machine was in dirt and sand. From the early to the late harvests, ‘the amount of dirt and sand removed by the cleaner increased 166 percent. Higher percentages of foreign matter were removed by the cleaner from the normal boll than from the stormproof types of cotton. Only 0.7 percent less foreign matter was removed by the cleaner from cottons harvested with the No. 16 machine than from the No. 15 machine at the early and mid-season harvests, and 3.4 percent less for the late harvest. The foreign matter removed in ginning varied so little be- M tween harvest dates, varieties, types of machines and locations that the differences were not considered significant, especially since the samples were ginned with a single-breasted 20-saw gin. The average total foreign matter removed in extracting, cleaning and ginning cottons machine-stripped at College Sta- tion for the early, mid-season and late harvests were 46.5, 42.9 and 41.1 percent, respectively, of the original stripped sample. Burs comprised most of the foreign matter removed by the extractor. At Lubbock, the average total percentages of foreign matter f1} removed from the original sample in extracting, cleaning and ginning cottons stripped With the No. 15 machine for the three *- harvests were 28.2, 31.1 ‘and 34.6, respectively. THE CLEANING OF MECHANICALLY HARVESTED COTTON ~ 4'7 The average percentages of foreign matter removed from cottons harvested with the No. 16 machine at Lubbock, in ex- tracting, cleaning and ginning, were 15.6, 19.2 and 17.5, re- . spectively, for the three harvests. Less waste was removed from cottons stripped at Lubbock With the No. 15 machine than from cottons stripped at College Station with the same machine. There was no apparent significant difference in the average foreign matter removed by the picker and cards. in preparation for spinning for the three harvests at College Station, as the average percentages were 20.4, 21.9 and 21.6, respectively, of the lint sample. The average percentages of waste removed by the picker and cards from the cottons stripped with the No. 15 machine at Lubbock were 16.9, 18.9 and 17.2, respectively,“for the early, mid-season and late harvests. There was only .3 percent more Waste removed by the picker and cards from the late harvested cotton than the early harvested cotton. Cottons stripped with the No. 16 machine followed the same trend in picker and card Waste as shown for "the No. 15 machine. Higher average percentages of 'waste were removed at Lub- bock by the picker and cards from the stormproof than from the normal boll types of cotton. The short-staple varieties were consistently low in ‘the amounts of picker and card waste removed in the spinning tests where cotton was machine-stripped. At both College Station and Lubbock, the average strength of 22 yarn in most varieties became Weaker at the late harvest. The yarn from the stormproof strain, CA 89A, however, be- came stronger as the harvest was delayed. The average strengths of the CA 89A yarn at College Station for the three harvest dates were 98.7, 99.4 and 101.7 pounds, respectively. The strengths of the CA 89A yarn at Lubbock for the No. 15 stripped cotton were 96.0, 100.5 and 101.1 pounds, respective- ly, and for the No. 16 stripped cotton were 99.8, 100.0 and 102.1 pounds, respectively. The 22 yarn spun from the long staple cottons was stronger than the yarn spun from the short staple cottons. Deltapine gave yarn strengths of 105.2, 100.0 and 97.2 pounds, respective- ly, while Hi-Bred gave yarn strengths of 85.3, 88.7 and 88.8 pc-unds, respectively, for the three harvests. The appearance of the 22 yarn spun from the short staple cottons was generally slightly better than from the long staple cottons. The neps in the card Web for Mebane 140 was consistently low for all varieties and dates of harvest for both locations. The average grade of the machine-stripped cottons at Col- lege Station was approximately strict good ordinary for all three harvests. 48 BULLETIN 720, TEXAS AGRICULTURAL EXPERIMENT STATION At Lubbock, Where the cotton was harvested with the N0. 15 i‘ machine, the average grades for the three harvests were SGO+, e. GO—- and GO+, respectively. At the early harvest, Hi-Bred ._ gave the highest grade of LM+, While Stoneville 2B gave the f lowest grade of GO. Where the cotton was stripped with the No. 16 machine, the average grades of the cotton for the three harvests were SLM, LM and SGO+, respectively. The grade differences show that the use of the field extractor resulted in higher grades at the early and mid-season harvests, and gave equal or better grades at the late harvest. The data do not indicate any injury to the staple by delaying the harvest until late in the season. The average maturity of the fiber was approximately 70 percent for all harvests of the machine-stripped cotton at both College Station and Lubbock. The total average percentages of foreign matter removed by the cleaner from machine-picked cotton at College Station, Where the cotton was poorly defoliated, were 8.1, 7.9 and 7.2, respectively for the early, mid-season and late harvests. The decrease in the amount of foreign matter reflects the effect of better defoliation at the later harvests. The amount of foreign matter removed in ginning machine- picked cotton averaged about the same as that removed in ginning machine-stripped cotton. The Waste removed by the picker and cards in the spinning tests of machine-picked cotton averaged 14.0, 14.2 and 14.6 percent, respectively, for the early, mid-season and late har- vests. The comparable amounts removed in the spinning tests for machine-stripped cotton were 20.4, 22.2 and 22.4, respec- tively, or about 8 percent more from the machine-stripped cotton. The strength of the 22 yarn spun from the machine-picked cotton was slightly stronger than that spun from the machine- stripped cottons at College Station. There was little difference in the appearance of the yarn from machine-picked cotton and the machine-stripped cottons at College Station. The machine-picked cottons at College Station averaged one- half to one and one-half grades higher than the same varieties when machine-stripped. There was no significant difference in the staple length of the machine-picked and the machine-stripped cottons.