77-626-14,000-L18O TEXAS AGRICULTURAL EXPERIMENT STATIEN B. YOUNGBLOOD, DIRECTOR COLLEGE STATION, BRAZOS country, TEXAS BULLETIN NO. 340 MAY, 1926 DIVISION OF AGRONOMY THE EFFECT 0F SPACING 0N THE YIELDOF COTTON v 4' ' 0 . ‘Imfllnnr, n11’. n ' "I n!’ ‘ IE1: “In a Q Q ‘ 0 Q 0° AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. O. WALTON, President memla§m.4¢»w;.ll<\_..DJL$QmJ"-IL,J ‘ i .'..-.-L.~....-_».. = as a border, or guard row, and is not harvested as part of the plat. The. area harvested on each plat consists of five rows 132 feet long, or 1/22 acre. . The cotton in these tests usually was planted at the optimum time of planting cotton at each substation. That method of preparing the land, of planting, and of cultivation which has been found best at the stations was used. A heavy rate of seeding was used in order to ob- tain a good stand. THE EFFECT OF SPACING ON THE YIELD OF COTTON 9 3| plants were given a preliminary thinning 10 days or two weeks y emergence, leaving about 25 plants more than the number desired .11.; ch plat. About 10 days later the plants remaining were thinned 5| desired stand by actual count. If deferred, or late, thinning ‘desired, preliminary thinning was done when the plants were about _. hes high, and the final thinning to the distances desired was made ys later. ' 1 thinning the plants to the desired distances, a cord, pole, or tape, g the proper distances indicated, was placed along the row, and a was left as near as possible to the desired mark. It was not 'ble to get a plant exactly at each mark but in all cases the desired ber of plants was secured on each plat. Al possible care was used in cultivating the cotton in the spacing 2 to retain and realize the stand desired on each plat. But despite i care, a few plants were destroyed or died from various causes. For i reason it was considered necessary to make an actual count of the ts on each plat at the time of picking. Frequently it was found , is count that the desired stand had not been obtained and the plat » to be placed in another spacing. For instance, a plat on which the Its were thinned to 9 inches, showed by actual count at picking to an average distance of 12 inches between plants, which was grouped >1 the 12-inch instead of the 9-inch spacing. This is the principal 1- why all of the spacings were not obtained every year. METHOD OF ANALYZING THE DATA ’~ practically all of the substations where spacing work with cotton ' conducted, all of the spacings were not secured every year of the _ owing to the fact that a recount of the plants was made at the ‘- of picking, which changed some of the spacings, as stated in the l eding paragraph. For this reason the average yield of each spac- could not be obtained for the entire period. It is obvious, there- _, that a true basis of comparing the average yields of lint of the ral spacings is not possible by using the averages for the entire 'od. This fact made it necessary to compute averages of each of the gral spacings for the years they were obtained in order to study them "a comparable basis. For instance, if the test was carried for five , s and all of the spacings were obtained four years of the five, the p,» age yield of each spacing was obtained for the four years; and an- } set of averages was made for the spacings which were obtained t. the five years. This gives a comparable basis for studying the aver- 1 yields of the different rates of thinning for the years they were se- But it does not afford an equitable basis for comparing the j age yield of each spacing for the duration of the test with the aver- , yields of the other spacings where some of the spacings were not »=ined each year of the test. _ .~ order to secure a fair comparison of the average yields of all rates .hinning for the duration of the test at any station, even though all 10 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION spacings were not obtained every year of the test, the yields of 1' cotton were calculated to percentages of the average yield of all p, . spacings. The method of" computing the average relative yields is a. plained as follows: The sum of the yields of all the spacings secur in any year is divided by the number of spacings. The results obtain: represent the average yields of all the spacings, or 100 per cent, or t_ possibilities of production under the conditions. This figure dividj into the yield of each spacing and the results multiplied by 100 givi the relative yield, expressed on a percentage basis. The relative yiel of each rate of thinning obtained in this manner is then averaged I the years it appears in the test, regardless of the number of years, e cept when less than two. In this way it is possible to compare the yiel of all the rates of thinning for the duration of the test without undue weight to large or small yields in any particular year when 1g ;_ of the spacings do not occur. ' a In most cases a second degree parabolic curve was fitted by the meth ~ - of least squares to the average relative yields and in two instances -;j_ the average actual yields of lint cotton as an additional aid in the i é terpretation of the data. The equationl Y za-l-bas-l-car’, was used g; fitting the curve to the data. The index of correlation, which is :_ abstract measure of the closeness of agreement between the observ yields and the fitted curve, was computed. On account of the small n u»! ber of observations to which each curve was fitted, the index of corr’ lation will, in all cases, have a slightly higher value than it would hav had if the curve had been fitted to a large number of similar observa! tions. Mills says, “The index of correlation may be looked upon as measure of the adequacy of a curve of a given type to describe the ref lationship between two variables.” While the uses of least squares and of relative yields are not in. tended to supersede entirely the average actual yields it is believed than; these methods are valuable in interpreting the data and in reaching mo I definite conclusions than would be possible from the average act yields alone. 1 RESULTS SECURED WITH NORMAL THINNING Spacing work with cotton thinned at the usual or normal time 0 thinning was conducted at the Main Station, College Station, and =1‘ the substations at Beeville, Troup, Angleton, Temple, Spur, Lubbock; Pecos, N acogdoches, and Chillicothe. As the work was conducted at widely separated points and under different conditions, the data secure at the several stations are reported separately. The conditions at ea station as regards elevation, average yearly rainfall, and character oif soil are given. This information will give the reader a fairly nil, general idea of the region surrounding each substation. A * _ ‘Mills, F. 0., Statistical Methods, Henry Holt and Company, New York, 19241] The methods used in fitting the curve to the data and in computing the standard‘? error, Sy, and the index of correlation are given on pages 432-441. THE EFFECT OF SPACING ON THE YIELD OF COTTON 11 Results at College Station College Station is located in Brazos County in the east central part of Texas. The elevation is about 370 feet. According to the weather records of the Texas Agricultural Experiment Station cooperating with the Weather Bureau, U. S. Department of Agriculture, the average an- nual rainfall at College Station for 36 years, 1890 to 1925, inclusive, is 38.21 inches. The amount of rainfall varies greatly from year to year, and there are times when crops sufier from drouth. The soil on the Experiment Station farm is a light gray fine sandy loam with a gray or mottled gray impervious subsoil. It is classified as Lufkin fine sandy loam by the Bureau of Soils, U. S. Department of Agricul- ture. The surface drainage of this soil is good to excessive, but the drainage through the soil is poor on account of the heavy impervious subsoil. The thinning, or spacing, Work with cotton Was conducted at College y Station in 191.4, 1915, 1916, 1917, and 1919, the results of which ap- pear in Tables 1, 2, 3, and 4. Two series of plats were used in these experiments, one of which contained 1 stalk to the hill and the other, 2 stalks to the hill. TABLE 1. Acre yield in pounds of lint cotton secured in spacing experiments with cotton at the Main Station, College Station, Texas, 1914, 1915, 1916, 1917, and 1919. One stalk to the hill. W} V} 0-H fig Average yield for Average :3 all years No. gm 1915-1919 1914-1919 tested years E 3 1914 1915 1916 1917 1919 inclusive mclusive tested ° B "a $3 Pounds Rank Pounds Rank Pounds Rank 3 . . . . . . 214 50 363.68 41.93 184.59 201 17 3 . . . . . . . . . . . . 201.17 7 4 6 . . . . .. 91 00 339.29 54.64 236.84 205 44 1 . . . . . . . . . . . . 205.44 5 4 9 291 192 69 38.02 58.77168.09 199 89 4 218.15 2 218.15 2 5 12 330 13 229 73 318.19 66 96 175.82 197 67 5 224.16 1 224.16 1 5 15 272 45 7 98 278.94 60 63181.84 184 84 8 202.36 5 202.36 6 5 18 255 19 253 98 286.34 77 00130.97 187 07 7 200.69 6 200.69 8 5 21 269 33 235 37 252.07 55 68161.56 176 17 10 194.80 7 194.80 9 5 24 252 89 347 67 256.76 60 71 154.68 204 95 2 214.54 3 214.54 3 5 27 245 49 284 12 233.91 64 61 123.06 176 42 9 190.23 8 190.23 10 5 30 275 28 304 93 251.74 61 18140.76 189 65 6 206.77 4 206.77 4 5 33 238.52 248.63 283.25 63.06 78.02 168.24 11 182.29 9 182.29 11 5 36 239.29 231.99 256.95 56.37 105.79 162.77 12 178.07 10 178.07 12 5 The yields secured in the series with 1 stalk to the hill appear in Table 1. In 1914 the largest yield, 330 pounds of lint to the acre, was obtained from the 1.2-inch spacing, but apparently the rate of thinning had no consistent effect on yield. In 1915, a favorable year for cotton production, the largest yields were obtained from the spac- ings ranging from 18 to 30 inches. The year 1916 was favorable for cotton production on account of the amount and distribution of rain- fall; The largest yields resulted from the closer spacings, 3 to 15 inches. In 1917, which was a dry year with only 17.53 inches of rain- i 12 BULLETIN NO. 840, TEXAS AGRICULTURAL- EXPERIMENT STATION} ,3 - ‘i fall, the spacings ranging from 15 to 36 inches, produced the best yields; In 1919 the excessive rainfall, 57 inches, was not conducive to large‘ yields. The closer spacings made the best yields. , ’ Average yields for the 4 years, 1915, 1916, 1917, and 1919, show that the spacing of 6 inches made the highest yield, but apparently there ., were no significant differences between the yield of this spacing and? the yields of the 3-inch, 9-inch, and 12-inch spacings. The spacing ofg 12 inches made the highest average yield, 224 pounds of lint to the‘, acre, for the entire period of the experiment. The yields of lint in; Table 1 were converted to relative yields, expressed in percentages, as Q, explained on page 9. These relative yields are given in Table 2. 0nd this basis of comparison the 6-inch and 12-inch spacings produced the most‘ satisfactory yields. TABLE 2. Relative yields of lint cotton secured in spacing experiments with cotton at Main Station, .- College Stationffexas, 1914, 1915, 1916, 1917, and 1919. One stalk to the hill. ' '5. 1914 1915 1916 1917 1919 ~ Average Number -; Spacing, inches 266.97 249.55 288.26 60.13 153.50 years ‘f between plants pounds pounds pounds pounds pounds tested z =100% =100% =100% = 00% =100% % Rank . % % % ‘70 v 3 . . . . . . . . . . . . . . . . . . . . . 86 126 70 120 100 8 4 j 6 . . . . . . . . . . . . . . . . . . . . . 77 18 91 154 110 2 4 -" 9 . . . . . . . . . . . . . 109 94 17 98 109 105 3 5 12 . . . . . . . . . . . .. 124 92 110 111 115 110 1 5 15 . . . . . . . . . . . .. 102 97 101 118 101 7 5 18 . . . . . . . . . . . . . 102 99 128 8 102 5 5 21 . . . . . . . . . . . . . 101 94 87 93 105 96 9 5 24 . . . . . . . . . . . . . 95 139 89 101 101 105 4 5 27 . . . . . . . . . . . . . 9 114 81 107 80 95 10 5 3O . . . . . . . . . . . . . 103 122 87 102 92 101 6 5 33 . . . . . . . . . . . . . 8 100 98 105 51 89 11 5 36 . . . . . . . . . . . . . 90 93 89 94 69 87 12 5 The yields obtained in the series with 2 stalks to the hill are reported t in Table 3. In general, the results of this series are similar to those secured in the series with 1 stalk to the hill, but the yields appear to be more erratic, as shown in Table 4, which gives the relative yields _ of lint. ' THE EFFECT OF SPACING ON THE YIELD OF COTTON POUNDS OFL/A/T PER ACRf 5 6 9 A? L5 l8 2/ 24 27 30 53 .56 sP/ic/Na //v x/vc/rzs Parabolic curve fitted to average actual yields of lint cotton in the series with one stalk to the hill at College Station. Figéure 1. l5 I42 A30 //<3 I06 ?6‘ 82 7'0 58 RELAT/Vf Y/[ZD l/VPD? (E/VT 9 /2 4s xe 2/ 2422.30 .5536 SP/ICI/VG /N UVCHES Figure 2. Relative yields of lint cotton (dots) in the series with one stalk to the hill at College Station and parabolic curve fitted to their averages (circles). 5 6 13 N 0 T. T A T S T N E M I R E P X E L A R U T L U C I R G A S A X E T O 4. 3 O N N I T E L L U B 14 w m flaw: 0N E2; m wflfi: m ii: 3x2 mNmfiw mmdmm $.03 . . . . . .3 w m $.22 N. mmwmi m mm a: w g2: Nb m2 8.8 one? wwhmm . . . . . . . . . . . . 1mm w w wmé: w 2E2 w . fimfi m 3&2 max: 8.3 mmwwm mmmN.N.m m 0N wwhwfi m wad»: mwbwfi mNmNw mpwwm . . . . . . . . . . ...N.m w I Nbmwfl m ww N.w~ N. 8Q: w mowmN 8 mm 3.2 5.2m mw aom . . . . . . . . . . . ...wm w w 2&2 m $58 w NAmwN N. 3.2; $62 Q26 mNmwmm mogmw w m ww 2: N wo m: m w» a2 w wwwfi 2 cfl 8.3 w» mmm 5.8m . . . . . . . . . . .. $3 w N 2N8 m wwUwNA .wT.N.Nm . H. . $4: 2;: 8.8 mwwmm 3M3 . . . . . . . . . . . 1.2 m m Emmi w mNnmwfi . .. . ....m. . . . made mméw mwéwm . . . . . . . . . . . . . . . . . . . 1mm m N. Ram: m N.N..mN.~ . 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Parabolic curve fitted to the average actual yields (circles) 0t lint cot- ton in the series with two stalks to the hill at College Station. l\ E / i“, A/zo % g; //0 Q m0 Q 90 i“ X 60 “$1 "r0 R a0 T \l 6E1 50 5 6 9 /Z /5 A? 2/ 24 2730 .55 56 JPflCV/VG //V //VC/—/E5 Figure 4. Relative yields of lint cotton (dots) obtained in the series with two stalks to the hill at College Station and parabolic curve fitted to their averages (circles). 15 16 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION A parabola was fitted by the method of least squares to the average u actual yields and to the average relative yields given in Tables 1 to 4, inclusive. The results of the curve fitted to the actual and relative yields of the series with 1 stalk to the hill are plotted in Figures 1. and 2, respectively. In the case of the‘ curve in Figure 2 the standard error, Sy, is 4.05, and the index of correlation, Rho, is .821. In both of these curves the peak occurs near the spacing of 12 inches. Theo- retically the highest point of the curve represents the spacing that will give the highest yields under the particular conditions. TABLE 4. Relative yields of lint cotton secured in spacin experiments with cotton at the Main Station, College Station, Texas, 1 15, 1916, 1917, and 1919. . ' Two stalks to the hill. 1915 1916 1917 1919 Number Spacing, inches 267.08 309.72 68.37 117 .97 Average years etween hills pounds pounds pounds pounds —————- tested =100% =100% =100% =100% % Rank % % % % 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 97 8 1 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 50 113 92 9 3 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 51 95 89 11 3 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 61 88 12 3 15 . . . . . . . . . . . . . . . . . . . . . . 125 114 89 102 108 4 4 18 . . . . . . . . . . . . . . . . . . . . . . 4 105 133 102 108 2 4 5 21 . . . . . . . . . . . . . . . . . . . . . . 87 96 100 111 98 7 4 3 24 . . . . . . . . . . . . . . . . . . . . . . 78 90 116 71 89 10 4 27 . . . . . . . . . . . . . . . . . . . . .. 101 . . . . . . .. 120 119 113 1 3 30 . . . . . . . . . . . . . . . . . . . . . . 104 85 122 99 102 5 4 33 . . . . . . . . . . . . . . . . . . . . . . 9 87 137 112 108 3 4 36 . . . . . . . . . . . . . . . . . . . . . . 116 77 120 86 100 6 4 Figures 3 and 4 show the results of the parabola fitted to the yields obtained in the series with 2 stalks to the. hill. In fitting the curveto . the relative yields, Figure 4, Sy was found to be, 7.29 and Rho .48.-i The peak of the curve fitted to the actual yields, Figure 3, occurs at 21 inches. While these curves do not fit the data very well, they indi- cate that in order to secure maximum yields comparatively wide spac- ing should be practiced Where 2 or 3 stalks are left to the hill. The results at College Station show that the spacing of 9 to 12 inches ,_; is the most satisfactory spacing’ where 1 stalk is left to the hill, al- though there is not much difference in yield where the plants are spaced ‘ 6 to 18 inches apart. Where there are 2 stalks left to the hill, the hills should be about 24 inches apart. A good stand of cotton for this part of Texas, as shown by these results, would be 10,000 to 20,000 plants to the acre. - \ Results at Substation No. 1, Beeville Substation No. 1 is located 5.6 miles northeast of Beeville, Beci County, in the southern part of Texas. The elevation is about 240 a ‘The standard error and index of correlation were computed by the method given by Mills, Statistical Methods, pages 436-441. ' THE EFFECT OF SPACING ON THE YIELD OF COTTON 17 feet above sea level. According to the weather records kept by the sub- station, the average yearly rainfall for the 30 years, 1896-1925, inclusive, was 29.03 inches. The soils on the substation farm belong to the_ Vic- ~toria series and are representative of the soils in the surrounding re- gion. Victoria loam is the principal soil type on the farm. This soil is naturally productive and is fairly easy to cultivate. The topography is rolling enough to afford good drainage. Spacing experiments with cotton have been conducted at Beeville since 1915. Two series of plats, one of which has 1 stalk to the hill, and the other 2 stalks to the hill have been used. The results obtained are given in Tables 5, 6, '7, and 8. The yields secured in the series with 1 stalk to the hill are given in Table 5. In 1915 good yields were obtained, averaging a little more than half a bale to the acre, although the total rainfall was only 14.60 inches. The previous year, however, had 45.50 inches of rain. The 6-inch spacing produced the highest yield, 340 pounds of lint cotton, and the 33-inch spacing the lowest yield, 266 pounds of lint to the acre. The test was not conducted in 1916. The rainfall in 1916 was 18.50 inches. The cotton crop was practically a failure in 1917, since only 9.40 inches of rainfall were recorded. In 1918 the yields were small, averaging 111 pounds of lint to the acre. There was too much rain in May, and practically no effective rainfall in July and August. The total rainfall for the year, however, was 30.83 inches. The 30-inch spacing made the highest yield, 145 pounds of lint, and the3-inch spacing the lowest yield, 64 pounds of lint, to the acre. Apparently the amount and distribution of rainfall were not con- ducive to large, yields in 1919. There was a total precipitation of 48.76 inches. May, June, and Julyhad 6.17, 3.93, and 5.69 inches, respectively. The largest yields resulted from medium to wide spacing and the smallest yields from the thickest spacings. Large yields were obtained in 1920, but apparently the spacing had little influence on yield. Low yields were obtained in 1922 and 1923. In 1922 the spac- ings ranging from 15 to 30 inches r-nade the best yields. In 1924 the 21-inch spacing made the largest yield, 211 pounds of lint to the acre. Fairly large yields were obtained in 1925. The aver- age yield of all the spacings was 260 pounds of lint to the acre. The highest yield, 271 pounds of lint, was produced on the plats with the plants 18 inches apart. It appears, however, that spacing within the limits obtained had no appreciable influence on yield.- 18 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION 2 N2 $42 . . . . . . . . ... . . . . . . . . . . . . . . . . $.22. . . . . . m 2 $.22 . . ... . hwmwh .. . . . . .. wodh wwéwN Tlhm w Z “@452 .. . . . . . . . .. moi: @042 mNhfi Dimw . . . . . . . . . . . . ...om w m 0922 hoéoN .. .. .. mad: 26mm ww.w2 mNhmw uNdhN . . . . . . . . . EN w h 0N6: 0922 32a what 09C. 55d 2&8 $.22 NNém $.95 w v 5:: mwdNN 2:8 mNMIN 3.2: 5.3 85mm $502 m5? 39K . . . . . . . . . . . . . IN w m 2S2 QAZN woQhN awafi 092A R? EAKN 2&2 05o“. wmimhN w 2 32: $83 R. 8N M582 Q m2 22$ 3.3m wmNi g5 32m m N 2&2 NhNmN wwavm $16 0902 No.2. 23mm 2.62 NwNQH 32$ M53» m. Z2 w o wmmomfi. U no.2 NmNnm weak. mmd: woNmfi NmdNm .T.m w w @0521 .....m..mm..m@.§.@.. 36v ooAhKN ohéw 29mm wmdwm m m ova“; . .. . .. . wEmNm wodw wméo . . . . . . . . .. m xcwfi mucnom mccsom mwcsom wucuom mwnsom mwqzom munsom 325cm mwcsom mwqsom wwcnom @033 mN . mama» =< éNzmNNN 3:8 -322 mN2 £2 mN2 NN2 cN2 22 22 22 22 32x3 qmaaafi wpwoh museum finmowaw uonfiuz .5.“ omm~w>< . .22 .22 .22 .22 dwuvh. .2=>8m J dZ 8:23 5E 25 o» “flu? onO d. HAQFH 6N2 6N2 6N2 .NN2 6N2 um i“ cofioo at? mgofiioaxu M562; E woksuom c038 “c: .3 mwanon E 32> 96¢. 19 THE EFFECT OF SPACING ON THE YIELD OF COTTON fl 0w 2w . . . . .. . . . . . . . . . . . . . . . . .. 2.. . . . . . . . . . . . . . . . . . . Iww m 0 M0 . . . . . . . . . . . . . .. 00 . . . . . . . . . . . . . . . . . N0 N0 . . . . . . . . . . . . . . . . . . . . . . 1mm v v wow .. . . . . .. . . . . . . .. 0: w: S; E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10m w m we mow .. hNfl m: v2 >0 m0 . . . . . . . . . . . . . . . . . . . . . . . InN w w N0 m2 m0 wv wofi Nw . . . . . . . mow SH N0 . . . . . . . . . . . . . . . . . . . . . . . .vN w w v0~ 00 S“ v: N0~ 00" 00 ..... w: N0 . . . . . . . . . . . . . . . . . . . . . . OUHN w b N0~ v2 vofi w: m: ww .. . . . . .. w: Nw v0 . . . . . . . . . . . . . . . . . . . _ . . .. wH w N .2: 00 3 m2 N: 02 >2 0: . . . . . . v0 . . . . . . . . . . . . . . . . . . . . . . . I5 0 ~ >2 wm 00~ m: H0 m: m2 m0 v0 m2 . . . . . . . . . . . . . . . . . . . . . . . .N~ w m. m2 .. . . . . . . . . . . . . . . . . . . . . .. vw m: C. 00 mwfi fi: . . . . . . . . . . . . . . . . . . . . . . . I0 w I hm . . . . . . .. 0w . . . . . . I mm mw 0w . . . . . . .. 00 w: . . . . . . . . . . . . . . . . . . . . . . 4 ..w m Nfi g . . . . . . . . . . . . . . . . . . . . . . .. m0 ww mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1m Q. N. w. $ $ fi w. Q. Q0 01am $ $00~M $00~M $02M $02M $02M $02M $02M $02M $02M 0033 200000 £00000 $00000 $00000 200500 $00000 $00000 $00000 200000 .3020 Pa?» |||||| l¥l wN.0wN $.02 20.03 M260 5.0mm 0v.v0H Q4: 21% mmdwN 0003000 .0235 £5225 000502 00203» £2 0&2 $2 NNO~ . 0N2 02$ 023 >23 22 6N2 ~80 .0NOH .02.; .023 .22 62S 688B $50600 J .0Z EES3=w 0m 00300 5? mfiSEEQ .5: 05 o» 0:3» 0:0 4002 .5: .w M17948 98 M5223 E 000003 00300 0c: we £301» 3303i 20 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION All of the spacings in the series with 1 stalk to the hill were not secured each‘ year of the test. Nine of the 12 spacings were obtained in 1915, 1917, and 1920; 8, in 1918 and 1919; 10 in 1922; '7 in 1924; and 5 in 1923 and 1925. For this reason it is not possible to compare the average actual yields of all the spacings for the period on a fair basis. For the 6 years, 1915, 1920, 1922, 1923, 1924, and 1925, the 12-inch spacing made the highest average actual yield, 237 pounds of lint cotton. When compared on the basis of relative yields (Table 6), the 12-inch spacing also produced the highest average yield for the 9 years of the test. ' \ \ s \ 3 s 8 0\ Q fizmr/ Vf may m/ Pb? cz/vr B‘ 567/2 /5/6’2/2f2/30.i356 SPflC/NG //V //VC//[.5 Figure 5. Relative yields of lint cotton (dots) in the series with one stalk to the hill at Beeville and parabolic curve fitted to their averages (circles). Table '7 reports the yields of lint obtained in the series with 2 stalks to the hill at Beeville. All of the spacings were not obtained every year. In fact, they appeared rather irregularly. For this reason it was necessary to make averages for groups of years in which spacings oc- curred to study the yields of the several spacings on a comparable basis. For the 3 years, 1919, 1920, and 1922, the 24-inch spacing made the largest average yield, followed in order of yield by the 30-inch, 15-inch, _ " . "if. ~ '<»ia<.~.i.au..s.wia 21 0A: Ow 9:3» 93F 6N3 Ea fifl: 6N3 .22 .22 S23 .53 dmxoh. 652:5 J dZ coflwwmnnm Q aoflou Ad? mwaofiioaxo mnmumnm 5MB wok-Rem cofioo an: we @252. E Eat» v.64 S MAMQQ. N 0 T m C Q fi . . . . . . . . . . . . . ... fi ........ ........ ........ F w a mmwwfi ... .. wwwn . . . . . . .. wwwmm wwmmh wwflmwm 111mm 0 w w 2.. 23 w 2:2 m Hmfiw .35 i 8v mwdw 3a: mm mm ww Mam ow D w w 2&8 m Eafi .. was? 3.5 3Q: 3 fi wwmwwfl . IKN L w w mmémw w 52w: ~ 32w swam 3 :5 058w ~52: ww Qm LQN E w m fifi: w Nwflm; v 5.3m wwAw E 5v Evmi 9.52 3% 56S . .13 H w N wwbmm $2; 8a» wwonw mwzmi Cfifiw Nmwwm . . w“ w w mwwt m Mae: m Qwfim $62 84> mfl m? 38H hmafl wwdw E N. N. v0.33 ~ 8&2 w £42 Qwfi a? 2.5.3 wmdw $.23 wmww 38m . ...N~ H w ow e993 .. . . . . n mTwmH mméa; whww wowmw wwéofi T w : M522 h @042 w wmdfi wflww oodom wwwm wmmwofi . . . . N N Nfi wnow w 330w voww wwwofl w O G xnmm mwcsom xcafi wwasom. 58m mwnsom N wwzfi m5: M muwwh 03mg 3m?» 2-22 Nwowifi $8 Q2 0N2 m3; £2 :2. m2: 82.52 A “~55: Z =m wmm~w>< ‘monofi P n53» on» .5.“ vmm~o>< wfiomnm S F O T C E F F E E H T A22 and 21-inch spacings. BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION The 24-inch spacing also made the highest av- erage yield for all years tested. When the yields are considered on the basis of the relative yields, as given in Table 8, the 24-inch spacing again made the highest average yield. TABLE 8. Relative yields of lint cotton secured in spacing experiments with cotton at Substation No. 1, Beeville, Texas, 1915, 1917, 1918, 1919, 1920, 1922, 1923. Two stalks to the hill. 1915 1917 1918 1919 1920 1922 1923 Spacing, Average No. inches 254.96 77. 84 1 54. 95 86. 32 452. 54 76-. 25 169.86 — years between pounds pounds pounds pounds pounds pounds pounds % Rank tested hills =10 = % =l00% =l00% =l00% =l00% =100 % % % % % % % 3 . . . . . . . . . . . . . . . . . . . . . . . 69 64 . . . . . . . . . . . . . . . . . . . . . 66 12 2 ‘ 6 . . . . . . . . . . . . . . . . . . . . . . . 69 111 66 72 . . . . . . . 80 11 4 9. . . . . . . . . . . . . . . . . . . . . . . 121 65 77 85 87 10 4 12 . . . . . . . . . 115 69 127 93 95 86 99 98 8 7 . 15 . . . . . . . . . . . . . . . . 106 81 120 102 94 112 102 6 6 18 . . . . . . . . . 105 105 92 . . . . . . . 126 113 104 108 4 6 21 . . . . . . . . . 108 108 109 122 97 107 . . . . . . . 108 2 6 24 . . . . . . . . . 99 . . . . . . . 94 102 134 122 . . . . . . . 110 1 5 27 . . . . . . . . . 99 ‘ 99 105 113 108 . . . . . . . . . . . . . . 105 5 5 30 . . . . . . . . . 99 119 106 59 110 120 . . . . . . . -102 7 6 33 . . . . . . . . . 95 95 148 . . . . . . . . . . . . . . 96 . . . . . . . 108 3 4 36 . . . . . . . . . 79 . . . . . . . . . . . . . .. 95 95 113 . . . . . .. 96 9. 4 /40 /5O /20 //0 /00 90 60 7'0 60 R/FLAT/l/E Y/[LD //V PE/P (EA/T .5 6 9 fiP/l/f/ Figure 6. N61 //\/ l/V/IHFKI /2 /5 w’ 2/ 24 27 .50 55 36 hill at Beeville and parabolic curve fitted to their averages (circles). Relative yields of lint cotton (dots) in the series with two stalks to the THE EFFECT OF SPACING ON THE/YIELD OF COTTON 23 _ By using the method of least squares, a parabola was fitted to the erage relative yields in Tables 6 and 8 (Figures 5 and 6). In the of Figure 5, Sy, was 6.47 and Rho was .79, while in Figure 6, Sy its 2.62 and Rho was .97. In both cases the peak of the curve occurs pear 21 inches. Considered ‘on the basis of these curves, the spacings j ging from 15 to 27 inches, inclusive, have made the most satisfactory "elds. These distances are recommended under the condition in the _gion of Beeville. With such spacings, there would be about 6,500 to 2,000 plants to the acre. While this range in spacing is rather wide, ; appears that the cotton plant can adjust itself to produce satisfactory welds within this range ofspacing. Results at Substation No. 2, Troup Substation No. 2 is located at Troup, Smith County, in northeast- 1| Texas. The altitude is 467 feet. The average annual rainfall r the 21 years, 1905 to 1925, inclusive, was 42.48 inches. The rain- l is well distributed throughout the year. The soil on the substation rm is a gray sandy loam, classed by the Bureau of Soils, U. S. Depart- ent of Agriculture, as Susquehanna fine sandy loam. This soil is ppresentative of large areas in northeastern Texas. f Spacing work with cotton was carried on at Troup only 3 years, p915, 1917, and 1918. Two series of plats were included inthe experi- ent, one with 1 stalk to the hill, the other with 2 stalks to the hill, tthe various distances. Cotton ofthe Mebane variety, Texas Station o. 804, was used in the experiment. The results obtained are reported ‘ Tables 9, 10, 11, and 12. s; Table 9 gives the yield in pounds of lint to the acre secured in the ries with 1 stalk to the hill. Only five spacings, 9, 15, 18, 21, and f inches were obtained each of the three years. Of these the 27-inch " acing produced the largest average yield of lint for the period, followed order of yield by the 21-inch spacing. It will be observed that the rgest yields each year were produced by the medium o-r wide spacings, lthough 1915 was a wet year and 1917 and 1918 were dry years. The 'elds of lint in Table 9 were converted into relative yields, which are 'ven in Table 10. When compared in this manner, the 27-inch spac- in produced the highest average yield. N O Tl- T A T S T N E M I R E P X E L A R U T L U C TL R G A S A X E T O A; 3 O N N Tl T E L L U B 24 fi w mNHNoN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. mKMNoN Iiimwm N m wToNN . . . . . . . . . . . . . . .. N wfioNN . . . . . . I . . . . . . . . . . . . . . . . . . . . . . . .. mmdwfi mwAKN . . . . . fmm N N NEomN N NNmomN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . wfiflmN . . . . . . .. wNwwN imflYom m ~ 220mm _ 23w ~ 915m ~ mm wmN _ 53w 25mm 213m mfifim . . . . 5N N w mZoNN w wfibNN .. . . . . . . . . . . . . . . wodflN wNANN IMITwN m. m N ww moN m wNJNAN m 2.2a N 3.8m N wwdoN ENAZN “mam: wmdNN . IAN m 0H 3. Q: N. 3Q: w $4.2: m Qvmt m @@.mw_ $..ww_ E i: wwaow przfi m m E 2: . mw wNN. m. 2.x: N. $52 w 3Q: Rhwmfi EA: wfiwmm I 1.2 N n mmwg . .. . m mmwan . . . . . . N922 nwdwfi .. .N~ m w N“ m2 b. NTmQN . w mwfiwfl w wmsfi m N5mm~ wwawfi M352 wméNN 1.4.. N NM wwmwfl m . . . . . .. 1.. w wwbw“ mwdwfi wNdwfi fi I wfiw: . . .. . . . . . . . . . . .. wfiwi m xcwfl mccnom xcwfl mwcsom EEK mwcsom Emmi wwcnom EEK wwcsom @033 £52m Em?» @023 33% £2623 22-22 x3722 @7292 . m3; :2 £2 nofifiwn uonisz =w omm$>< , 3:2: Emmr» o5 Ho“ E: “o mwzsom E 2E.» 3am www$>< .WBMONQW .5: v5. 3 53w oqO $23 .22 .23 dmnou. 550C. .N dZ coifiwnnw um cofiou n33 wEQEivQxo mEomaw E “Huh-cum c0300 E: Ho @252. E 32% 33w d HAQEH : Relative yields of lint cotton secured i Troup, THE EFFECT OF SPACING ON THE YIELD OF COTTON TABLE 10. 25 n spacing experiments with cotton at Substation No. 2, Texas, 1915, 1917, 1918. One stalk to the hill. 1915 1917 1918 Average No. Spacing, inches between 235.78 178.96 200.72 ———i-————— years plants pounds pounds pounds tested =100% =100% =100 % Rank % % % 3 . . . . . . . . V . . . . . . . . . . . . . . . . . . . , . . 74 . . . . . . . . . . . . . . . . 74 12 1 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 71 88 11 2 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 96 92 95 8 3 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 99 102 5 2 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 62 99 - 9O 9 3 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 92 91 9O 1O 3 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 108 105 103 4 3 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 . . . . . . . . 109 102 6 2 v 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 118 137 114 123 1 3 h 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 . . . . . . . . 118 115 2 2 33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 95 . . . . . . . . 105 3 2 36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 101 7 1 t i. E é E l /30 /2Z //4 m6 98 90 Pfl/IT/VE Y/[ZO //l/ PIA’ [EA/T 5 6 9/2 /5 /8 2/ 24 Z7 30 35 .56 SP/JC/NG Figure 7. //V HVC/ffé Relative yields of lint cotton (dots) in the series with one stalk to the hill at Troup and parabolic curve fitted to their averages‘ (circles). The results obtained in the series containing 2 stalks to the hill are given in Tables 11 and 12. Only four spacings, 15, 18, 21, and 24 inches, were obtained each year. Of these, the 24-inch spacing pro- 26 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION - '“ at“ 322% l duced the highest average yield for the three years. The yield decreased l as the distance between the plants decreased. For the 2 years, 1917' and 1918, the 33-inch spacing gave the highest, and the 27-inch the lowest average yield. When compared on the basis of average relative yield for all years tested, Table 12, the spacing of 12 inches produced the highest, and the 36-inch spacing the lowest, yield for the three years. TABLE 11. Acre yield in pounds of lint cotton secured in spacing experiments with cotton at Substation No. 2, Troup, Texas, 1915, 1917, 1918. Two stalks to the hill. _ ’ Average acre yield Spacing, for the years Average all No. inches be- 1915 1917 1918 years tested years tween hills 1915-17-18 1917-18 tested Pounds Rank Pounds Rank Pounds Rank 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 . . . . . . . . .. 218.51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 218.51 3 1 . . . . . . . . .. 213.58 4 1 12 . . . . . . . . . . 211 84 243.48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227.66 1 2 15 . . . . . . . . . . 192 58 167.87 183.86 181 43 4 175.86 5 181.43 9 3 18 . . . . . . . . .. 213 07 171.58 192.44 192 36 3 182.01 3 192.36 8 3 21 . . . . . . . . . . 236 11 171.27 193.60 200 32 2 182.43 2 00.3 6 3 24 . . . . . . . . . . 274 53 151 .52 206.75 210 93 1 179. 13 4 210.93 5 3 . . . . . . . . . . . . . . . .. 136.40 207.07....... 171.73 6 171.73 10 2 30 . . . . . . . . . . . . . . . . . . . . . . . . 219.92 . . . . . . . . . . . . . . . . . . . . . . . . . . 219.92 2 1 33 . . . . . . . . . . . . . . . . . 219 84 169.29 . . . . . . . . . . . .. 194 56 1 4 56 7 2 36 . . . . . . . . . . . . . . . . . 150 59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 59 11 1 TABLE 12. Relative yields of lint cotton secured in spacing experiments with cotton at Substation No. 2, roup, Texas, 1 15, 1917, 1918. Two stalks to the hill. 1915 1917 1918 Average Spacing, inches between hills 222. 88 176. 56 196. 13 —————————— No. pounds pounds pounds year =l00% =100% =100% % Rank 3 % % % 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 . . . . . . . . . . . . . . . . 98 6 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 96 96 8 1 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 138 . . . . . . . . 116 1 2 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 95 94 92 9 3 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 97 98 7 3 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 97 9 101 5 3 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 86 105 105 4 3 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 106 92 10 2 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 112 2 “ 1 33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 86 106 3 2 36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 . . . . . . . . 85 11 1 é have an elevation of about 22.5 feet above sea level. . brown to black clay" with a dark-gray or gray subsoil. It is classed as _ Victoria clay by the Bureau of Soils, U. S. Department of Agriculture. i This soil is perhaps the most extensive soil type in the Gulf Coastal THE EFFECT OF SPACING ON THE YIELD OF COTTON 27 RZZ/IT/l/f Y/flfl //V PfR [FA/T 569/2/5/52/2427505556‘ SPAC/NG M/ UVCHES Figure 8. Relative yields of lint cotton (dots) in the series with two stalks to the hill at Troup and parabolic curve fitted to their averages (circles); A parabola was fitted by the method of least squares to the average relative yields obtained with 1 and 2 stalks to the hill, reported in Tables 10 and 12, respectively. F-igure '7 shows the curve fitted to the rela- tive yields from the series with 1 stalk to the hill. In this case the standard error, Sy, was 7.61 and Rho was .78. The peak of the curve occurs at the 30-inch spacing. Figure 8 gives the curve fitted to the average relative yields obtained in the series with 2 stalks to the hill. i, Sy was 8.58 and Rho .47. In this case the highest point of the curve occurs at the 18-inch spacing. While these results should not be re- garded as conclusive, they indicate that spacings ranging from 18 to g 36 inches, will give the most satisfactory yields on the sandy soils of L the region. Results at Substation No. 3, Angleton Substation No. 3 is located 3-} miles northeast of Angleton, Brazoria County, in the east central part of the Gulf Coastal Plains of Texas. The average annual rainfall for the 12-year period, 1914 to 1925, in- i clusive, was 47.7 6 inches. The topography of the region is prevailingly flat with poor drainage. The experimental fields of the substation farm Plains of Texas. It is rather stiff and intractable in nature and is The soil is a dark- ' 28 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION somewhat diflicult to cultivate. The soil is naturally productive when provided With adequate drainage. The spacing work with cotton at Angleton was conducted for 8 years, 1917 to 1924, inclusive. Cotton of the Mebane variety, Texas Station No. 804, was used in all of this work. The results obtained in these investigations are given in Tables 13 and 14. Q /ZZ Q Q b Q! Q» o~ I! /?[Z/17'/V[ 7/1510 //V P55’ Kf/VT m N 3 ,6 9 A? /5 n9 2/ 2427303354 $PA£//v6 //V //vc/-/£.5 Figure 9. Relative yields of lint cotton (dots) at Angleton and parabolic curve fitted to their averages (circles). The yields in pounds of lint to the acre are given in Table 13. Only four rates of thinning, 9, 12, 15, and 18 inches, were secured every year of the test. The average yields of these spacings were practically identical for the 8 years, 1917 t0 1924, inclusive. For the 5 years, 1918, 1921, 1922, 1923, and 1924, the 6-inch spacing produced the high- est, and the 3-inch spacing the lowest, average yield. The 12-inch spac- ing made the highest average yield, 224 pounds of lint to the acre, for the 6 years, 1917, 1919, 1920, 1922, 1923, and 1924, although the yields of the 9-inch, 15-inch, and 18-inch spacings were about as large. It appears that the character of the season did not have much influence on the relative rank in yield of the different spacings. For instance, 1917 and 1918 were dry years and the spacings ranging from 3 to 18 29 .=£ 2: 8 58w 3o .2 MJEAFH giiucw 4N2 3 :2 fimxoh. £3255. M. .02 isfifiéw 0m cofiou s33 wwfizbiwmxo @502; E vogue» c038 E: .3 255cm E 32% 30¢. N O T w C m AW- -¢.~ --|- -- -¢- - - - ¢ - . - - --- . ¢¢~ - - - - - - - - - - ‘ ¢ -- - F w w .§.@w_ 0 ~0~w0~ mmemm 0w.wN 38w . . . . . . .. 3.8m omtNw ommfiN xrm». 0 w N ww Q: N. wPmQN XIII . . . . . .. wmiwvm woSN @002 . . . . . .. 32m flaw 0w 3N 1.10m D > ~ ww w“: w 0v 5N . . . . . . . ... Nodwm oNflm $0.5m . . . . . . .. 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REE: P QQQESZ miomaw .S Em?» o5 .5.“ E2» owm$>< F O T C E F F E E H T 3O BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION w ow ow wow mm mow .. . . . . w ww nw wow on www . mo ow. w“. . . . . .. ... . Iilww w o wo how ww www . vo w“. wo .. . Ziow w. w No mow wm haw .. wow an mw ww 1mm w. w. mo wow ww oww 8 wo ww wow .. .. Ida w. w oow oow 8 3 .. wow Nww 8 8 .. . . . .. . . Iwm w w wow mm wo oow wvw wm vow No Nmw . .. . . .. . . . . . . ... . . . . . .... . . . .ww w w wow “a wow ow wfl 8 omw mow wow . . . . . . . .. . . . . . . . . . . . . . . . .2 w w oww wow wmw 8 Now ma www wow w: . . . . . . . . . . . . Ilmw w w N: 8 mww wm www. 8w www wow wow . . . . . .. . . . . 11o M w mo w. E m Wm .27. Hi. m“ gé ......fi.w.nuiuwnmm..wm s wk. w. w. w. Q. x Q. . fiam fi. $9.? $2.? Q62" $2.? $02" $2.? ~32“ ~32“ wwwwuw $525 25:3 $5.3 mug-om mwnsoa wwizoa mwnson wwcsom Em?» |‘|||l| 32m Ea» ow d: wafi ww . www wwwmw 2Z5 85R 352a =QQEQQ 3:2: fiqsfim $2252 ownhrwww $2 .82 g: E2 omow 22 wwow 22 :5: of 8 53m onO dZmw-woaw Jmmw cw nwmw dmxfiw. éofizmc< .w .02 cowwuwwnsm w“ c0300 A33 mwcufiwwunno mfiofia E wufiwoom nofiou wc: we 2J2» ofiwawomw .3 mfimfiw 0w W-wqi». n»... ---"-m-_-vw>~»~v~ v-w-w ~ -> It appear in Table 15. THE EFFECT OF SPACING ON THE YIELD OF COTTON 31 inches made the best yields, while in 1919 and 1920, both of which were years of heavy rainfall, similar results were obtained. In 1922 the yields increased roughly as the distance between plants increased up to 27 inches. In 1923 the largest yields were obtained from the closer spacings, while in 1924, which was a favorable year for cotton produc- tion, good yields were obtained throughout the range of spacing. The yields of lint in Table 13 were converted to relative yields, which are reported in Table 14. When compared on the basis of relative yields, the spacing of 9 inches made the highest average yield for the entire period of the experiment. Apparently there were no significant differences between the average relative yield of the 9-inch spacing and the average relative yields of the 6-inch, 12-inch, 15-inch, and 18-inch spacings. ' A parabola was fitted by the method of least squares to the average relative yields in Table 14, the results of which are plotted in Figure 9. The standard error, Sy, was 6.17 and the index of correlation, Rho, was .74. The peak of the curve occurs at the 12-inch spacing, which is in agreement with the average actual yields. These results show that in the humid part of the Gulf Coastal plains of Texas the plants should be spaced about 12 inches apart in rows of ordinary width, or in such a manner as to allow about 15,000 plants to the acre. The distance between plants, however, may vary from 6 to 18 inches, making it possible to have 10,000 to 29,000 plants to the acre, without signifi- cant decrease in yield. Results at Substation No. 5, Temple Substation No. 5 is located 5 miles west of Temple, Bell County, in the blackland belt of Texas. The altitude is 740 feet. The average yearly rainfall at the substation for the 13 years, 1913 to 1924, inclu- sive, was 35.99 inches. The average annual precipitation at the city of Temple for the 36 years, 1890 to 1925, inclusive, was 33.76 inches ac- cording to the records of the U. S. Weather Bureau. The soils on the substation farm are dark-brown to black clays belonging to the Sim- mons and Abilene series. Both of these are good cotton soils. ' The spacing work with cotton was conducted at Temple from 1915 to 1921, inclusive, yields being secured every year. Two series of plats have been carried, one with 1 stalk to the hill, the other with 2 stalks to the hill, at the various distances. Lone Star cotton, Texas Station No. 1383, was used in these tests from 1915 to 1919, inclusive, and Belton cotton in 1920 and 1921. Tables 15, 16, 1'7, and 18 give the , results obtained. The yields of lint cotton secured in the series with 1 stalk to the hill In 1915, about the average amount of rainfall, 34.26 inches, occurred at Temple. The largest yield was produced by the 6-inch spacing, but in general the wider spacings, 2,1 to 33 inches, A made larger yields than closer spacing. There were 26.27 inches of _ i; rainfall in 1916, which was well distributed during the growing season, N O I T A T S T N E M I R E P X E L A R U T L U C I R G A S A X E T 0 4. 3 0 N N I T E L L U B 32 h Nfi wwwwu m wmniw m wflmom w wfifim Emmmm hwuwt. 3X02 .53 8Q: .225“ GPQ: . . . . Iww N. m mwwow fl 5N5 ~ owhww N Show 8&3 mm 2a ww w~m R Ev 8 8; wo wwm 8 m? 111mm N. w 3m? N wNxwmw N “main w aPmwm mKxwwm wwmwmw NH 5mm mmww 2 62 8.3K fiawm . . . . . .3 N. 2 5.3% w 9.3m m, owamm w nmawm 53w 3 m? R43 mm? mm m2 Rdfi hwwmm . . . IR N. w wvdow m mmwmm m 3.5m wfifim. Shown .23? gimgflom 2H2: $45.” “mfia . . Jfi w w mvswm w Qswm w Qmawm . firmfi 2E5 mwd: 5.? 5st fiafim . . . . .._N u ~ 2.2m w“ gfiww v “@905 ~ 2.2m Qflhwm @@.2K mflfiw 8n? mwwi ww w? mw.mw~ . :2 w I wwwwm h .:..E.~ N. mdwE N. vwhwm Gfihwm 2.. hi wo mom RAK. ww m: awwmw 2.22: . . . . 1.3 ... b £15m w . mwrdfim w 3.2m Mwfowm. mwfiw ohmwfi. wmwfim ~32. waumfi iwmwm hwwi Ilmfi w w Mawwmm S wfiwmm .. mwwwm w» $m3.w.u&...... wwafi . . . . . . ..§.@2 w w. mwwmm . .. . 2 mwwmm . . . . . . .. @m.>om wwXZwwN fimzt: 3A8 . . . . . . ..mw.vw~. . . . . ..w w m mu hwm Q mm hwm E mmm S ..§E¢<.@~...... mw m: . . . . . . .. QM: .. Iw xnafl mwcsom xnwm mwcaom xcwfl wwcsom xcmfl 225cm . 352a @033 “s28 8-3-2 2.5m oZmEQE Q2 ofl: 22 £2 $2 £2 n23 uowBfifi Emu» mpmuh =m -M:-E-.h42 avwpfifi Eafimzwfi @225 .625: Z 352,4 . @5225 Each o5 wow 32> @2234 .5: o5 o» 53w 0:0 63.33am Jwmn 3 n23 émnou. dcufion. .m dZ comamumnsw an cofioo n33 ficvfiioano @583 E web-vow aofioo i5 we @253 E Bu?» o~u< .2 MAQAFH , .. “w-(pa-w-“W. THE EFFECT OF SPACING ON THE YIELD OF COTTON 33 and fairly large yields were produced. The largest yield, 408 pounds of lint to the acre, resulted from the 18-inch spacing. . ' The season of 1917 was unusually dry; only 20.75 inches of rainfall were reported, although it was well distributed in May, June, July, and August. Medium spacing of the plants gave best results. In 1918, 29.36 inches of rainfall were recorded at the substation. This Was not well distributed, since no rain fell in July andonly .07 inches in August. As a result, very low yields were secured. By referring to the yields obtained in 1918, Table 15, one will see that there was no appreciable effect of spacing on yield. ~ - In 1919, 47.45 inches of rain occurred. Fairly good yields were ob- tained. Apparently, the rate of thinning did not have much influence on yield, since relative yields above the-average occurred throughout the range of spacing. The season of 1920, with 44.73 inches of rain- fall, was unusually favorable for cotton production in the blackland belt of Texas. The lowest yield was 599 pounds of lint to the acre from the 9-inch spacing, and the highest yield, 920 pounds, from the 33-inch spacing. The spacings, 18 to 36 inches, produced larger yields than the closer spacings. In 1921, the yields obtained were smaller than the average for the 7-year period. It appears that the rate of thinning had no consistent relation to‘ the yields obtained, although the two closest spacings made the lowest yields. _ Only eight of the twelve rates of thinning were obtained every year of the test. Of these eight, the spacing of 18 inches made the highest average yield, 310 pounds of lint to the acre. All of the spacings were obtained in each of the five years, 1915, 1917, 1919, 1920, and 1921. During this period the spacing of 33 inches made the highest average yield, and in general the yield declined as the distance between plant increased or decreased from 33 inches. The high average yield of the 33-inch spacing was due to the exceptionally high yield of 920 pounds of lint of this spacing in 1920. TABLE _16. Relative yields of lint cotton secured in spacing experiments with cotton at Substation No. 5 Temple, Texas, 1915 to 1921, inclusive. One stalk to the hill. _ 1915 1916 1917 1918 1919 1920 1921 Spacing, Average No. inches 208.39 298.12 162.66 79.47 227 .94 757.32 254.08 years between pounds pounds pounds pounds pounds pounds pounds tested plants =100% =100% =100% =100% =100% =100% =100% % I Rank % % % % % % 3 . . . . . . . . . '54 . . . . . . . 101 . . . . . . . 104 92 89 88 12 5 6 . . . . . . . . . 137 . . . . . . . 100 . . . . . . . 9 82 82 99 9 5 9 . . . . . . . . . 95 . . . . . .. 95 . . . . . .. 113 79 112 99 1O 5 12 . . . . . . . . . 93 129 88 88 107 98 100 100 4 7 15 . . . . . . . . . 95 110 100 100 9 99 105 100 7 7 18 . . . . . . . . . 8 137 109 98 103 106 113 108 2 7 21 . . . . . . . . . 102 . . . . . . . 109 98 81 107 104 100 6 6 24 . . . . . . . .. 117 109 115 114 103 102 99 108 1 7 27 . . . . . . . . . 109 81 98 96 116 103 96 100 8 7 30 . . . . . . . . . 118 89 92 86 103 109 105 100 5 7 33 . . . . . . . .. 111 89 9 119 96 121 103 104 3 7 36 . . . . . . . .. 81 56 104 101 87 102 89 11 7 34 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION The actual yields of lint reported in Table 15 were converted into i~ relative yields, which are given in Table 16. The 24-inch spacing pro- duced the highest average relative yield for the seven years of the test, although the yield of the 18-inch spacing was about as large. The yield of the series with 2 stalks to the hill appear in Table 17. . In 1915, the largest yields were produced in the spacings ranging from ‘y, 9 to 24 inches, While in 1916 the Wider spacings gave the best results. The largest yields in 1917 were produced by the closer spacings. In . both 1919 and 1920 the spacings ranging from 15 to 33 inches gave i the largest yields. fifl/IT/Vf 7/510 //V Pff? Cf/VT .5 6 9 l2 /_5 /6 2/ 24 27 30 55 36 SPA C/A/G //V //VC/-/[.€ Figure 10. Relative yields of lint cotton (dots) in the series with one stalk to the hill at Temple and parabolic curve fitted to their averages (circles). For the entire period of the test, 1915-1920, inclusive, nine rates of thinning with 2 stalks to the hill occurred each year. Of these, the 30-inch spacing made the highest average yield, 329 pounds of lint to the acre, followed in order of yield by the 21-inch, 27-inch, and 18-inch spacings. The yields of lint Were converted to relative yields, which ap- pear in Table 18. When compared on the basis of relative yields, the 18-inch and 21-inch spacings made the highest yields. 35 d3 o5 3 9:3.“ 03F 63.31:: 6N2 o» Boa £56m. 6380B 6 dZ dofiwfinnw w“ acfioo n33 wwcofizuonxo mcwommu H wuunovm nowwoo on: we 3.5.3 E 32> P6< .2 mqmwd. N O T m C w 2 $2.8 w gonm w bwANw N. $1.5 wwmwww £45 wwww wN.ww wwNww 5.2: ..........ww F w w g8» w wnwww m owwNw w wit». owoR. wwoow S? woNw >m.fi.m “M85 .9" 0 w m oo.oNm fi Rmwww w wowmw ~ oo oNm 2 wow wwdw mwow 2 m: wwghw ww o5 ow D w w ow.NNm w oowhm w. ~o.wNw w ow NNm Nw 3:. 38w wwww ww.mw~ S wow wo ooN INN L w fl 2.8m o wmswm 2 Nwwhw o 3 mow 5 Now wwww 2.8 w“. NN~ mhswm wwoNN ...wN E w w woBNw N wowww m Nfimmw N 35m mo www omomw NoNb wo S; wwNwm mo NmN ZEN H w w hNoNm w mwohm N. wNoNw w 5.3m wN o3 wNAow wo.ww oN 9: oo www wwwNN .. w~ w w omwdm m 54am N Nwoww w ow 8m ww wmw Nwwwm NNAK. Nw fioN oo woN N~ mwN £1.12 E w Z wNwow w wNoww w 2:3 w wNwom S wwn wNNNw mTww wwéw~ EwwN oo wmN .~.N~ H w N wNNww 2 wNNwm o 52w wN w? mhéNw woooN ow owN 5.3m H6 T m w mfiwww S wfimmw . NoNww NWwoN wwmwofi .. . ...I...w N w o whim NH owwww wwwow woowfi w~ow~ NwoHN . w O G xnwm mwcsom xawfl mwnsom xcmfl mwasom V185 mwcsom . N 8:8 2i M 3w?» 82B 8.2 8.2-23 vzmso=o 0N2 22 22 $2 £2 B2 amnion A 5.252 wbwoh =w -.w._-£-m~2 dmmwmoi . 3:2: P omm~o>< wfioamw S Ewoh o5 3w 32h oww~o>< F . O T C E F F E E. H T 36 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION TABLE 18 Relative yields of lint cotton secured in spacing experiments with cotton at Substation No. 5, Temple, Texas, 1915 to 1920, inclusive. / Two stalks to the hill. _ 1915 1916 1917 1918 1919 1920 Spacing, Average No. inches 211 . 50 339. 97 151 .48 69.33 351.32 724.24 years hetyveen pounds pounds pounds pounds pounds pounds tested i hills =100% =100% =100% =100% =100% =100% % Rank ‘ '70 % ‘7 % % a . . . . . . . . . . . . . . . . . . . e3 5s . . . . . . . . 52 9s 7s 12 g 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 . . . . . . . . 59 92 94 10 . . . . . . . . . . . 105 75 138 ........ 92 98 102 5 5 12 . . . . . . . . . . . 111 79 120 98 92 103 100 7 6 15 . . . . . . . . . . . 111 89 133 106 101 102 107 3 6 18 . . . . . . . . . . . 107 110 125 99 114 93 108 1 6 21 . . . . . . . . . . . 115 93 104 128 94 107 2 ,6 24 . . . . . . . . .. 104 116 81 117 118 82 103 4 6 27 . . . . . . . . . .. 95 123 96 81 114 100 102 6 6 30 . . . . . . . . . .. 83 113 76 87 126 112 100 8 6 33 . . . . . . . . . .. 84 113 54 111 117 108 98 9 6 36 . . . . . . . . . . . 91 103 56 96 89 120 92 11 6 R § \D Q: Kn 3i Q V1 5751/1 77 V6’ Y/{LO //V PFR [F/VT U1 v» Dir?“ I I FT-PT-IT- 1 T1 1W’? » is 5 6 9 /2 L5 /8 P 24 Z7 50 55 .36 "3 SPAC/NG /N //VC/7’[§ ‘ Figure 11. Relative yields of lint cotton (dots) in the series with two stalks to the hill at Temple and parabolic curve fitted to their averages (circles). A parabola was fitted by the method of least squares t0 the average relative yields obtained with 1 and 2 stalks to the hill. Figure 10 shows the curve fitted to the relative yields obtained in the series containing 1 stalk to the hill. Sy was 3.65 and Rho .77. In plotting the curve in THE EFFECT OF SPACING ON THE YIELD OF COTTON 37 Figure 11, Sy was found to be 2.73 and Rho .93. In each case the peak of the curve occurs at 21 inches. These results show that in actual farm practice the cotton plants should be left about 21 inches apart under the conditions in that part of Texas, although the distance be- tween plants may vary from 12 inches to 30 inches without reducing the yield to any considerable extent. This range in spacing would require 6,000 to 15,000 plants to the acre. Results at Substation No. 7, Spur Substation No. 7 is located at Spur, Dickens County, in the north- western part of the State, in the Permian Red Beds region. The ele- vation is 2,200 feet above sea level. The average annual precipitation for the 12 years, 1914 to 1925, inclusive, was 21.66 inches. The rainfall is fairly well distributed during the growing season, although there are times when the crops suffer from drouth. This is a sub-humid region and the cotton crop usually does not have an excess of moisture. The spacing experiments with cotton at Spur have been conducted on Abilene clay loam and Miles clay loam soils. The Abilene clay loam is dark chocolate-brown in color with a dark-brown clay subsoil. The Miles clay loam is dark chocolate-red in color with a heavier and somewhat darker subsoil. These. soils are naturally productive and are representative of the soils in that section of the Red Beds region. Spacing experiments with cotton have been conducted at Spur since 1914. Mebane cotton, Texas Station No. 804, has been used in all of this work. In 1916 and in 1920 the cotton in the experiment was de- ' stroyed by hail, and as the work was not conducted in 1918, these three years are not included in the averages. Table 19 gives the yield of lint obtained. Unusually large yields were secured in 1914, which were no doubt due to the exceptionally favorable season, since 34.13 inches of rainfall were recorded during the year. The spacing of 15 inches made the highest yield, 620 pounds of lint to the acre. The lowest yield, 282 pounds, resultedfrom the 36-inch spacing. Inspection of Table 19, however, seems to show that the yield had no consistent relation to spacing. In 1915, also a favorable year for cotton production, the largest yields were obtained from the spacings varying from 6 to 21 inches, but apparently the spacing had no consistent effect on yield. i The crop season of 1917 was dry, with a total of 11.91 inches of precipitation for the year. The spacings ranging from 6 to 12 inches made decidedly the larger yields. In a general way the yields decreased as the spacing increased from 9 to 36 inches. Yields of all the spacings-in 1919 were considerably higher than the average for the entire period of the test. The spacings within the limits obtained appear to have had no appreciable influence on yield, although the highest yield, 393 pounds of lint, was‘ obtained from the 24-inch spacing, and the lowestyield, 284 pounds of lint, from the 36-inch spacing. ~ Baez o5 .8“ omm~u>< m 24mm . fig: H mafia“ mmai .. m 2.4.8 2 ..%H.H.H.. ...:.¢w 9X. . 2N5 mmpg >26.“ q mfifiw a . .. . . . . .. z“ R 2m 2E5 omafi mflmE m Nflwfi w. . ma?“ 43w.“ Mafia... 3Q; ¢m.@@~ N. 8 Mam N. 8.3m Qwwfi 21m .$....wE. . . . S m2.“ @954 an? b wmehw w 9.8m Swwfi 6P3 . .. fivwmw wfiwhm 9H2: Qmim w 9:3 m wfiwwm 9&3“ 2...? 2.. m: $1.3 2.9a $.23 wwamm w £65 m ooamw 8Q: 2X4. 3Q: 3 5w 8am.“ 3mm: 2&3 w 83w m 8.3m 9.1.5 2. E 8 EM 8 25 5.2a mmwqm w 32w w Nbfim Qrmi 8.? mast wmswm 24am @250. Ewtm ._. £58 1W: .~.§._.@mm. 9:2 own? 3&2 3mm» mqia wmamm m 9Z2 9:2 3% oiwi .. H mfiiflonm mfiflflonm mwflioam mwiflofim \m@.-H:Om wwifionm W@.-Hnw°m mfiflflonm “TAM-Baum .l.s B m m “manna QNAWE m 1m? B~QQ< -522 $2 5: g: R2 22 .22 22 m. m... m... 9 P. —eq saqou s1ueld Imam; N 0 n A T .8 T N E M I R E. P. X E L A R w L U C I R G A X E T 0. 4_ 3 0. N N I m U. U B 38 .2 mqmfiw .5: 23 8 53» 25 . dfiufionm Jam“ 3 v23 Juno? Guam K dz caflgnnsm pm flofiouw n83 Bcofiionuv mnmowan E wounuon Q0300 um: ~o nwnuon E 30$ o.~o< THE EFFECT OF SPACING ON THE YIELD OF COTTON 39 The year 1921 was a normal year for cotton production. The aver- age yield of all the spacings was 247 pounds of lint to the acre. The \ closest spacing obtained, 9 inches, produced the highest yield, 287 pounds of lint to the acre; while the widest spacing, 30 inches, made the small- est yield, 210 pounds to- the acre. In 1922, the 3-inch spacing made the largest yield but the 6-inch, 15-inch, 18-inch, and 24-inchspacings made yields which indicate that the distance between plants had very little influence on yield. The low yield in 1923 was due largely to the unfavorable distribution of rain- fall during the growing season. The 12-inch spacing produced the largest yield, 81 pounds of lint to the acre. The yields diminished as 4 the distance increased or decreased from 12 inches. The yields in ' 1924 were below the average. The rainfall for the year was 11.16 inches or about one-half of the normal rainfall. The spacing evidently did not have much, if any, effect on yield. /70 7 \ b‘ R m /34 A22 //0 w 0o 0o p m 74 62 RZZAT/l/E Y/EAD //V P54? CE/V 569/2 5/02/2427505356 JPAC/NG //v /NCH£5 Figure 12. Relative yields of lint cotton (dots) at Spur and parabolic curve fitted to their averages (circles). All of the twelve spacings were not obtained during any year of the '1 test. In 1917 and 1919, however, only the 3-inch spacing was missing. 1 The 9-inch, 15-inch, and the 18-inch spacings were the only spacings ; which occurred every year of the test. The average yields for the eight N O I T A T S T N E M I R E P x E L A R w L u C m G A S A x E T 0 4. 3 0 N N. I T E L L U B 40 m Nfl mm . . . ow mm vm m ow mm . . . . . . .. . hm ww wh c2 New Q S hm. . . . . . . . . . . . mm vow Nh ww m m mm . . mm . . . . . ma: mh mm o2 h h 8 2: 8 N2 . . . . . . . Zfi mh 3 x2 h w 2i 8. 8 . . . . . . . 8 n: hm 22 N: w m i: 8 m2 m: x2 x2 i: 2: N2 w v i: 8 Q: Q: 8 8H 8 z: m: w N c: i: w: 8 i: m3 8 .. w ~ m: 2: m2 2.. 8: i“ w: m8 8 m m MW We Mm m. .55. .5... E... x2. w. x x x x .x x x i?“ x x8? x8? x8? x8? x8? x8? x8? x8? @033 mvnsoa @253 “@558 $568 255cm wwcnoa “.525 mwason Ewe» 3.3“; 8.8 3.82 32x 8.5». .0882 8x2.» 8x8 .5555 Z . omm~o>< $2 ma: 8.2 5: 22 hflfi .22 :2 .383 Gooauofi museum $52» am 633:2: Jug B v23 dmnwh. wBQm .h .0 Z cofi-Bwnsm an cofioo at? Bcwfiioawo mfiowmw E uoksuom .23 o5 8 53w ocO 6N HAQ smaller as the spacing was increased. In 1914, a large yield was secured, " which was probably due to the amount and favorable distribution of N O I T A T S T N E M I R E P X E L A R U T L U C m G A E T O, 4 3 Q N N I 2 L L U B 42 2 2.2.22.2 m2.2....2 2.2 22.2.2 2.2.22 m2..2.2.m 2.2.2.22 2.2..22.m .......2.2.H2.2.m 2.2.2.2 22.22. 2.2.22 .. ...2.2 2. 22.2mm .............22..2.22 ................w...2.22.22 2.2.2m2. 2.2.22.2 .........2..22.2 2.2mm .22 2.2 22.2mm 2. 22..m2m 2.2.22.2 2.2.2.2.. m2.2mm mm 2.mm 2 2.2.2 mm 2.2.2 m2.22 .......2.2.22.m 2222.2 .2.2..2wm2 :2... 2. 2.2..22.m 2 2.2..2.2m m2..22.2 2.2.2.22 2.28m 2.22 22.2.2.2 2.2.2.22. 2.2.22.2 ..:...22..2.2.2 22.2.2.2 12m 2. 2m22m 2.2..2.2m 2. 22..2.2.m m2..22.2 2.2.m2.2 m2.2.2m 2.22am 2.2.22.2 22.2.2.2 2.2.222 2.2.22.2 $2.2m ...2.m 22 2.22m m 2.22m 2.m.2.m2 2.m2.m2 2222a 2.2..mmm 22.22.222.222. 22.2.2.2 ..%...2.m 2.mm 22..2m2 22.2.2.2. 22.22 ...2m 22 2.2..2.2.m 22.2.2.m ... 22..22.m 2.2.222 m2..2.2.m 22.2.2.2 2.22m .. 2.2.2.2. 2.2.22.2 22 22.2 22.2mm 2m.22.2 2.2.22. 22.222 :22 22 2.22m 2 2m 22m 2.2222 22mm... 22..m2m 2.2..2m 22.2.22 2.22.222. 2.2. 22.2 .%...2.2.H22m 2.2.222 22.52. 22.2.22 :22 22 22..m2m 22.2mm 2. 22..22m 22.2.22 22..m2m 2.22m mwsmm 2.2.2.22 m2.2m2. 22222 22.2.2.2 22 2.2m 22..2m2. 8.2.2.2 . m2 m2 25.2mm 22.2mm 2. 2.2.22m 2.... 222 2.2 2.22.. 22..m2m R. 2.2m 2.2.22.m 2.2.222. 22 22.2 2m 2.22 22..m2m 22.2.22 2.2.22. 22.2.2.2 :2. 2.2 22..m2m 2 2.m.22m m2..22.2 22.222 m2.2.2 :H....2m m2..2 2.2. 22.2 2.22.2.2 22.2.22 22.222 22..m2.2 22.2.22. :2. 2. 22..m2m 22..m2m .....m2.2.22 22. 222 2.2. 2mm .. 2m2. 22.2.22 22..m2m .. . :2 ||l 22.25am 2.25am 2222mm 22.52am mwcuom 22.25am 2w2222om 22.25am 22.25am wwcsom 2.52am 2.55m 2©2222om ww2222om 32.22am 2.55m 1. M... 1% 2.3.22 2m.mm 2.m.2m-mm 2.. .22. .2. 28.2 2m2- -22-2-2.22.2 um... w.“ =< 2-2.22.2 2m2 2m2 mm2 2m2 2.m2 22 22 222 2.22 222 2.22 222 Wwm. m 20.2 E2.» 2.222225. W2... 22E a5 2.2 2:22.22 220 .2.>2222o222 4&2 o2 m2..2 $2.3m. £02322 .w .o Z 222.2222..22222w .222 22322.2. 22223 3222.52.22.98 22.22222. .222 “$2222.22 2332.2. 222: 22. 222222.22 222 2.22.222 2.22.4 AN 22.22242. THE EFFECT OF SPACING ON THE YIELD OF COTTON 43 rainfall during the growing season of cotton. The total rainfall in 1914 was 31.43 inches. The widest spacing obtained, which was 21 inches, produced the highest yield, 660 pounds of lint cotton to the acre, while the spacing of 12 inches made the lowest yield, 621 pounds of lint. A study of the yields in 1914, Table 21, shows, however, that there is no consistent relation between yield and spacing of the plants. In 1915, the rainfall at Lubbock was 31.88 inches, and was distributed rather favorably during the active growing season. The average yield of all of the spacings was 324 pounds of lint to the acre. Six inches was the closest spacing obtained that year and it made the highest yield, 362 pounds of lint to the acre. In a general way the yield de- creased roughly as the spacing increased. Similar results were secured in 1916. c Low yields resulted in 1917, probably due to the scant rainfall of 8.73 inches. The rainfall of 15.03 inches in 1916 probably was a contributing factor-towards low yields in 1917. The spacings ranging from 3 to 12 inches made the largest yields but these were not satisfactory. The yield became smaller as the distance between the plants was increased from 12 to 36 inches. Low yields resulted in 1918; the average yield of all the spacings was 152 pounds of lint cotton to the acre. The low- est yields were produced on the plats with the closer spacings, 3 to 9 inches, but an examination of Table 21 shows that the yield apparently was not otherwise correlated with the distance between plants. T The year 1919 was favorable for cotton production at Lubbock, and gas a result an average yield of about 419 pounds of lint cotton to the E-acre was produced in the spacing test. The 6-inch spacing made the ilargest yield, which was 501 pounds of lint to the acre. It would ap- pear, however, that the spacing had no consistent infiuence on yield, psince yields above the average for the year appeared throughout the grange of spacing. Similar results were obtained in 1920. In 1921, the rainfall was considerably below the average, there being §16.75 inches. About an average yieldof cotton, however, was pro- iduced, which was probably due to the rains in June and September with a favorable maturing season and late frost. The largest yields re- sulted from the 9-inch and 15-inch spacings. Yields somewhat below the average for the 12-year period were obtained in 1922, which was a dry year with a rainfall of 14.59 inches. The largest yield, 263 pounds 10f lint to the acre, was produced by the 21-inch and 27-inch spacings. The yields decreased in general as the distance between plants in- creased or decreased from these spacings. a Yields considerably above the average for the 12-year period were obtained in 1923, although conditions were unfavorable for securing a tand. It was necessary to replant the cotton in the test, which was f7» one on June 15. This gave a short season for producing cotton. The ' -inch spacing made the largest yield, 356 pounds of lint to the acre. a he yields of the 6-inch and 9-inch spacings, however, were about as rge, being 353 and 350 pounds of lint to the acre, respectively. N 0 I T A T S T N E M I R E P X E L A R U T L U C I R G A S A X E T .0 4. 3 0 N N I T E L L U B 44 w N2 a» ww S ww 5 N. 2:. Q B .......jxnw...flw: o 2.2 hm N22 ... .. . . . . . . . . . . . . . . om 202 m2 . . . . . . .. 0w 2% .. . .. . 2 02 hm . N02 002 N02 mm hm mw mN2 . . . . . . .. w» mm hw a m N02 i: M3 2N2 $0 h22 2: 002 S N» m w wm 2: :0 m2 202 0w 0m w02 mw m2 . . . . .. . . . . . . . . . . . . 22 0 202 mw N02 NN2 mm 0m 022 h22 . . . . . . . . hm mm v02 Nm 22 h mm 2w mm 2m o2 ... . . 222 002 2m mm m2 002 N02 22 2» v02 0m 02 82 m22 wm wm x02 . . . . . . . . m02 m2 wm 202 22 m v02 h02 mw . 202 202 0m 002 N22 m22 022 ...... hm m2 N2 N m2 22 m2 w... h22 2N2 002 .5 hm mN2 h02 002 w02 M... M m”: .22.“... m" M N; 5e... w. mm mm" ..€.. 9F HHHH N N N N N» N N . N 2N N N N $002M $002M $002M $002M $002M $002M $002M $02M $002M $002M $002M $002M 2633 Nani $ 2.550 wucson mucson $2502 mwcsom @2522 mwczon mvcson mucnom mwcson wwcnon 225022 Em?» Irll mh.022 0N. 2Nm 2~0.h2N whbmN $9: 0mm? mwafi 0.92.2 2m.mmN hméNm 2h.hm0 3%; 2on5: Z omw~o>< 2N2 mNm2 NNm2 2Nm2 0Nm2 m2m2 w2m2 h2m2 w2m2 m2m2 22m2 m2m2 I I l smeld uaazm —aq saqoug ‘Hugoedg :2 s: 8 a“: 26 622.205 .vNm2 o2 m2m2 £882. Jmvonnsd .w .072 aoSwfiflizw 2w cofioo 2222B niofiioaxo mfiomam E wwgsuow .333 2c: 2o m2.2v2zmo>fiw_wfl .NN M22242. THE EFFECT OF SPACING ON THE YIELD OF COTTON 45 In 1924, low yields were produced, the average of all of the spacings s 140 pounds of lint to the acre, which was approximately 120 pounds wer than the average yield for the period of the experiment. A study Table 21 shows that apparently the spacing had- little effect on yield, i pi“ yields above the average for the year occur throughout the range f spacing. . Only one spacing, the 9-inch, occurred every year of the test. There , ed. The 6-inch spacing made the highest average yield, 268 pounds lint, for the six years 1916, 1918, 1919, 1922, 1:923, and 1924. It l1! made the largest yield for all‘ years tested. The spacing of 36 ‘hich it occurred. k v; \ § S fi Q‘ l‘ c». 0| I/F a b, 0a Q1 ‘<1 5 6 9 /2 /5 n9 2/ 24 27 J0 J3 J6 SPA C/N 6 //v //VC//[5 Figure 13. Relative yields of lint cotton (dots) at Lubbock and parabolic curve a fitted to their averages (circles). ,' The yields of lint cotton reported in Table 21 were converted to rela- - e yields, which are given in Table 22. The 6-inch spacing produced _; highest average relative yield, followed in order of relative yield by 7» 9-inch, 12-inch, and 15-inch spacings. When considered on the pjere only two years, 1916 and 1918, in which all of the spacings oc- ' ches made the lowest average yield in each of the period of years in 46 I BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION basis of relative yields these spacings would be the ones to recomm‘ in actual farm practice. _ A parabola was fitted by the method of least squares to the aver relative yields, the results of which are plotted in Figure 13. Syj this case was 3.65 and Rho was .83. Thehighest point of the cu . occurs at 12 and 15 inches. The curve shows that the yield decre g as the distance increased or decreased from 12 to 15 inches. t, these results it is concluded that the optimum spacing for the conditi at Lubbock would be~12 to 15 inches, but a satisfactory range of sp_ ing in farm practice would be one of 6 to 21 inches since there is . significant decrease in yield within this range of spacing. ’“ Results at Substation No. 9, Pecos’ Substation No. 9 is located 3% miles west of Pecos} in Reeves Coun in western Texas. The latitude is 31 degrees, 25 minutes north; 1o tude, 103 degrees, 31 minutes west. The elevation is 2,580 feet abo sea level. The region is somewhat arid, the average rainfall for Q 8 years, 1914 to 1921, inclusive, being 11.64 inches. The yearly ra' fall varies considerably. In 1917 there were only 2.61 inches; in there were 19.70 inches. Reeves silty clay loam and Reeves fine s w loam are the principal soil types on the substation farm. Substati No. 9 is an irrigation station. Thinning experiments with cotton were conducted at Pecos fr 1916 to 1919, inclusive. The results secured in 1918, however, are 1! given here for the reason that there was a shortage of irrigation war due to engine trouble and all plats in the experiment Qlid not_ the same amount of water. This destroyed the accuracy of the resul which were, therefore, discarded. a TABLE 23. Acre yield in pounds of lint secured in spacing experiments with cotton at Substation N w; Pecos, Texas, 1916, 1917, and 1919. - One stalk to the hill. Average for the years Spacing, Average all inches 1916-1917 1917-1919 years tested between 1916 1917 1919 plants - Pounds Rank Pounds Rank Pounds Rank 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 . . . . . . . . . . . . . . . . . . . . . . . . 224.20 . . . . . . . . . . . . . . . . . . . . . . . . . . 224.20 3 ‘ 9 . . . . . . . . . . . . . . . . . 64 10 250.63 . . . . . . . . . . . .. 157 36 157 6 12 . . . . . . . . . . . . . . . . . . . . . . . . 200.40 . . . . . . . . . . . . . . . . . . . . . . . . . . 200 40 4 15 . . . . . . . . . . 268 32 42 45 250. 60 155 38 1 146 52 2 187 12 5 18 . . . . . . . . . . 281 93 . . . . . . . 253.50 . . . . . . . . . . . . . . . . . . . . . . . . . . 267 71 1 21 . . . . . . . . . . . . . . . . . 34.27 229.80 . . . . . . . . . . . . . 132 03 3 132 03 8 24 . . . . . . . . . . 187 28 29.65 . . . . . . . 108 46 3 . . . . . . . . . . . . . 108 46 10 27 . . . . . . . . . . 211 69 24.77 . . . . . .. 118 23 2 . . . . . . . . . . . .. 118 23 9 30 . . . . . . . . . . 193 22 22.33 194.80 107 77 4 108 56 4 136 78 7 33 . . . . . . . . . . . . . . . . . 23.8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 87 11 36 . . . . . . . . . . . . . . . . . . . . . . . . 225.90 . . . . . . . . . . . . . . . . . . . . . . . . . . 225 90 2 1The substation was removed to Balmorhea, about 35 miles from Pecos, 1922. " THE EFFECT OF SPACING ON THE YIELD OF COTTON 47 TABLE 24 tive yields of lint cotton secured in spacing experiments with cotton at Substation No. 9, i Pecos, Texas, 1916, 1917, and 1919. One stalk to the hill. , 1916 1917 1919 Average No. . acing, inches between plants 228.48 34.49 228. 72 —-—-—-—--——-—- years pounds pounds pounds tested =l00% =100% =100% % Rank % % % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 9 6 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 110 148 1 2 : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 7 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 123 110 117 3 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 123 111 117 2 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 100 1 4 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 82 86 84 8 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 93 72 82 9 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 65 85 78 10 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 69 69 11 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 99 5 1 ¢ heresults of the test are reported in Tables 23 and 24. Only two l: ings, the 15-inch and the 30-inch, appeared each of the 3 years. a] spacings ranging from 9 to 21 inches gave the best yields each The average yields for all years tested show that the best yield ‘ulted from the 18-inch spacing. The yields of lint cotton given in ble 23 were converted to relative yields, which are given in Table When compared in this Nianner, the 9-inch spacing produced the hest average yield. While these results are not conclusive, they indi- ‘_ that under irrigated conditions in that part of the State spacing. ‘e plants 6 to 21 inches apart will give best results. Results at Substation No. 11, Nacogdoches Substation No. 11 is located at Nacogdoches, Nacogdoches County, eastern Texas. The elevation is 292 feet. The average yearly rainfall r 23 years, 1902i to 1924, inclusive, was 50.96 inches according to . ords of the substation. The spacing experiments with cotton have conducted on Orangeburg fine sandy loam soil. Investigations on the spacing of cotton were conducted at Nacog- ' hes from 1915 to 1920, inclusive. The results are shown in Tables w to 30, inclusive. Three series of plats were used, one with 1 stalk ' the hill, one with 2 stalks to the hill, and the other with 3 stalks the hill, at the various distances. The yields of lint obtained in the series with 1 stalk to the hill are ven in Table 25. All of the 12 spacings were secured in only 2 of the -' years, in 1915 and in 1918. For these 2 years the 30-inch spacing de the highest average yield, 258 pounds of lint to the acre, followed order of yield by the 33-inch, 21-inch, and 27-inch spacings. For e 4-year period, 1915-1918, inclusive, the 21-inch spacing made the f t average yield, 209 pounds of lint to the acre. The 30-inch, 33- - ch, and 24-inch spacings followed closely in the order named. 48 w T A T S T N E m. R E P X E L A R w L U C I R G A S A X E T 0.. 4 3 0. N N . I m L U B v m 8x2 0 SARI 0 005.2 . . . . . . .. .50: $.02 05m: 0v0mN . . . . . . . . . . . . . 20m 0 m mPNfi m 0h R3 N b0. EN 5N0 00.8 Nfl .02 ~N.vm~ 3&2 movvm . . . . . . . . . . . . 1.3 0 v @002 N 2 ~00N ~ 00.0mm mN00 w? ~N 8&2 NOSN~ 3x2: mmvNm . . . . . . . . . . 1.10m m N Nv m: m m0 mi v wmdNN avNw 00.02 Ram N0hw~ fiifi . . . . . . . . . . . . INN 0 0 N903 v ~0H~0~ 0 00.2w .58 075 N702 v02: TMWvNN 000g . . . . . . . . . . . . . IvN v ~ v0.00» .50? m vvvmN . . . . . . . . . .. Q02 $.02 Nw.w0N R02.“ . . . . . . . . . . . . . IN m 0 Qwmfi . . u 0 0>AON N7m0~ 2.0m 0003 $.02 0v.wmN . . . . . . . . . . . . . 1M: m 0~ $.02 . 0 .. E. m2 N. ~N.00N 0:: N002 0.01.5 £0: 00.3w . . . . . . . . . I3 m I vfimfl . . w 8.2: 3% 00.: 52w: 00.0: 00.0NN . . . . . . . . . _ IINM v h $.03 :0 .. .NN.mv~ 2 N062 . 0mN0~ $9.: 0052 3:2 . . . . . . . . . . Q ---.- -§. -.-..- -.-¢.»- . . . . -.-.......-@i N w 0vNv~ . NH ovNvfi . . . . . . .. hwéhfi vmN: 1m 018m mwcsom Mflflrm . 3.58m 018M 2500A 0000.3 .3020 0003000 30oz 0033 M53.» 0572-22 02.; .023 0N2 023 023 22 023 £2 300E £5225 000502 =0 @0292 . 0.80.» o5 .50 owmhz/v. :5 2: 8 58w 2.0 030305 dNmTmfimw 6008B fionoovmoow Z .: .0 Z aofimamnsw 0m 00300 :33 mvEoEmuonxo 058% E 000000» c0300 0:: 00 000000 E 003mm 0.64 5N mdmififi THE EFFECT OF SPACING ON THE YIELD OF COTTON 49 l. Apparently the character of the season had no marked influence on j» relative rank in yield of the diiierent rates of thinning. For stance, 1915 and 1916 were average years as far as total rainfall was is was true also for. 1917 and 1918, both of which were dry years. imilar results were obtained in 1919 and 1920, both of which had nor- i» or more than normal precipitation. p, The yields of lint in Table 25 were converted into relative yields, ihich are given in Table 26. On the basis of relative yield, the 21-inch acing produced the highest average yield for the period of test. In eneral the spacings from 18 to 33 inches made larger yields than closer TABLE 26 iflelative yields of lint cotton secured in spacing ex eriments with cotton at Substation No. 11, N acogdoches, Texas, 191 to 1920, inclusive. One stalk to the hill. 1915 1916 1917 1918 1919 1920 ; . Average No. g Spacing, inches 239 .08 163.66 123.64 167.86 20.37 81 .51 ————— years i- between plants pounds pounds pounds pounds pounds pounds tested ~ =100% =100% = 00% =100% =100% =100% % Rank % % % % % % 3 . . . . . . . . . . . . . . 47 . . . . . . . . . . . . . . 102 . . . . . . . . . . . . . . 74 11 2 6 . . . . . . . . . . . . . . 62 . . . . . . . . . . . . . . 102 51 59 68 12 4 9 . . . . . . . . . . . . . . 58 66 109 115 . . . . . . . . . . . . . . 87 1O 4 12 . . . . . . . . . . . . . . 92 68 . . . . . . . 106 84 105 91 8 5 15 . . . . . . . . . . . . . . 68 103 111 6 . . . . . . . 88 9 5 18 . . . . . . . . . . . . . . 100 110 . . . . . . . 98 148 127 117 3 5 21 . . . . . . . . . . . . . . 130 128 130 94 . . . . . . . . . . . . . . 120 1 4 24 . . . . . . . . . . . . . . 115 137 86 94 84 76 99 6 6 27 . . . . . . . . . . . . .. 122 113 75 98 . . . . . . . 101 102 5 5 . . . . . . . . . . . . .. 136 110 103 115 105 118 114 4 6 33 . . . . . . . . . . . . .. 144 95 109 94 160 114 119 2 6 36 . . . . . . . . . . . . . . 105 106 85 70 . . . . . . . . . . . . . . 92 7 4 ncerned, and the medium to wide spacings produced the largest yields. ~ Table 27 reports the yields of lint secured in the series with 2 stalks to the hill. This series included spacings from 9 to 36 inches. All of these spacings were obtained only two years, in 1915 and 1918. For these 2 years the spacing of 27 inches made the highest average yield, 338 pounds of lint to the acre. The 21-inch, 24-inch, 30-inch, and 36- inch spacings each produced more than .300 pounds of lint to the acre as an average for the 2 years. The 9-inch spacing gave the lowest average yield, 231 pounds of lint to- the acre, for the same period. Only six spacings were obtained through the three years, 1915, 1917, and 1918. Of these six, the 27-inch and 36-inch spacings produced the high- est average yield, 266 pounds of lint to the acre, although the 24-inch and 30-inch spacings produced practically as large yields. The yields of lint in Table 27 were converted into relative yields, which are given in Table 28. On this basis of comparison, the 21- inch spacing made the highest, and the 9-inch spacing the lowest, average relative yield for the duration of the experiment. N 0 TL T A T S T N E M I R E P X E L A R U m U C I R G A s A X E T 0 4 3 5o BULLETIN “NO m w 0000a ~ 38w v 000$ 23m N062 0062 2.02 56$ m m mvxim 0 00.0mm $.02 No.2. oommm m 2 NR5: m mmdmm m. 0P3». 59mm: 00.0mm 030$ 00.0.3 007.03 w m wflmmw m $63 fi 00.0mm . Nfiwww 862 00.3.4 300w HT Tm. 11.5 u» 0 2 2: w 00 EN m mmbmm 5a» 32w mm m2 3.8% . .. 26m w w wmmzm m N903 fimxmmi mméwm $.02 ovyhm . .. . . . . . . I3 m u x. mom 0 3 mom w 3.2m . $.02 3% m“ mmm . .. .. Z43 m ~ 500m n 300m mmhwfi 09mm...“ 1.15 m 0 mwdom n. mwwom 0 wwkwm LIL . muémfl $.02 moéwm .. m m. 004mm 0~ 005m .. .. 00.02 09.3w mafia 225cm xamm Twcsom xawfl Tmwazom . @033 . 023 023 >23 023 22 2:4 aofifivn @222 aqséw “imam 03mm» @525 072-022 021 22 HQAQBZ zu oma~o>< m3?» o5 .8.“ uww~o>< dfinsiqm .023 3 n23 fiwxoh. donooumoomz .2 d3 o5 on 5:3» 03H dZ nofiuwmnnm um nofioo at? 35.8135 mumuwnn 5 00503 nofioo F: “o nwanon E @303 o.8< .3 NAQ

93; wmsfi AKA: Qvwmm . . . . . . . . IIITSN w m $53 w mafia N NNJUN n Qawm Nwafi @¢.£~w¢._28.w¢m .u.~.. w w “xxfiw .m 52m fi 82.03% N mwNmN .h.>.ww~sv$_ 2M3; 8.8m . . . . .. MN N N QWARN . .. . . . . . . .. m géhN .. Nwmwé... 185mm N w mNmJm . . M mN.m~m .. . nm¢mN............v~.ohm . .. . . mfi 833 xcwfl wwnsom xcwfl wucnom xcwfl _ muasom xcwfl _ mwasom whwoz ma?“ whwoh wilzéfi 2-2-22 M32 .22 22 22 :2 22 22 2:: c0350 poniuZ zw ommuo>< . nonoi £50m m 3x2» on» .3.“ omauo>< . :2 2: 8 9:5“ 08.5. .O>@w5~Ofl@ OH 683m. JUJOOUUOONZ Tmw .02 uoflmumnsm ad flOawOO nHGQEmQOQKQ mfiuwan Cm wohwoom GOuaOO wflfi a0 RUN-BOG Gm n20?» OMO< 6N MAMFQ. THE EFFECT OF ‘SPACING ON THE YIELD OF COTTON 53 iThe yields of lint obtained in the series with 3 stalks to the hill are ven in Table 29. This series included spacings ranging from 15 to ,5» inches. All of the spacings were secured in 1915 and 1918. The -inch spacing made the highest average yield, 315 pounds of lint; and 27-inch spacing the lowest yield, 201 pounds of lint t0 the acre, for ‘ese 2 years. For the 3 years, 1915, 1917, and 1918, the spacings of is and 24 inches gave the best yields, each with 243 pounds of lint to 3 acre. The 27-inch spacing made the lowest average yield, 184 unds of lint. For the 4 years, 1915 to 1918, inclusive, the highest erage yield was produced by the 33-inch spacing, but the yields of the .--inch, 24-inch, and 36-inch spacings were practically as large. The 'elds are so erratic that it is not possible to draw definite conclusions // 4- /06 98 90 82 74- 6 6 58 9514/1 fin/z‘ ik/[Zib )1) 2Z2? i i .5 a 9 /2 /5 /a 2/‘24 2r 5o 55 56 SPAC/NG //v //vc/-/£5 1 Figure 15. Relative yields of lint cotton (dots) in the series with two stalks to the hill at Nacogdoches and parabolic curve fitted to their averages (circles). _ A parabola was fitted by the method of least squares to the rela- ve yields secured in the series with 1 stalk and with 2 stalks to the '11 (Figures 14 and 15). In fitting the curve, Figure 14, Sy was 55 and Rho was .81, while in Figure 15 Sy was 10.17 and Rho .58. the peak of the curve occurs at 27 and 30 inches for the series with a stalk and with 2 stalks to the hill, respectively. The peak represents 54 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION the optimum spacing of cotton under the conditions of the experi These results, studied in’ connection with the actual yields, show" ‘g the largest yields have been obtained from spacings ranging from to 36 inches, whether there were 1 or 2 stalks to the hill. In gen however, the series with 2 stalks and 3 stalks to the hill made slig-_ larger yields than the series with 1 stalk to the hill. These results l cate that in the region of Nacogdoches the spacing of cotton shoul about 27 to 3O inches with 2 or 3 stalks to the hill, but the sp g may vary from 18 to 36 inches without serious reduction in yiel TABLE 30. Relative yields of lint cotton secured in spacing experiments with cotton at Substation N Nacogdoches, Texas, 1915 to 1919, inclusive. J Three stalks to the hill. 1915 1916 1917 1918 1919 Spacing, inches, 313.81 155 . 97 193.26 200.23 47.83 between hills pounds pounds pounds pounds pounds ————————— =100% =100% =100% =100% =100% % Rank Average % % % % 15 . . . . . . . . . . . . . 120 . . . . . . . . . . . . . . . . 127 . . . . . . . . 124 1 18 . . . . . . . . . . . . . 116 . . . . . . . . . . . . . . . . 93 . . . . . . . . 104 2 21 . . . . . . . . . . . . . 95 91 75 144 . . . . . . . . 101 4 24 . . . . . . . . . . . . . 97 84 122 93 . . . . . . . . 99 6 27 . . . . . . . . . . . . . 2 91 78 72 119 88 8 30 . . . . . . . . . . . . . 105 . . . . . . . . 99 82 . . . . . . . . 95 7 33 . . . . . . . . . . . . . 6 113 119 103 83 101 5 36 . . . . . . . . . . . . . 98 121 107 86 99 102 3 Results at Substation No. 12, Chillicothe Substation No. 12 is located 4} miles south and 1 mile west I Chillicothe, Hardeman County, in the Red Beds region of Northw Texas. The altitude is 1406 feet. The average annual rainfall ~ 25.74 inches for the 20 years, 1906 to 1925, inclusive, and 28.84 in =7 for the 6 years, 1919 to 1924, inclusive, during which the spacing periment was conducted. The rainfall is well distributed through » growing season. The soil types on the substation are mostly clay lo a andfine sandy loams, belonging to the Vernon and Kirkland se 31 These are brown to reddish-brown soils, and are representative of ~ principal areas in this section of the Red Beds region. " TABLE 31. Acre yield in pounds of lint cotton secured in spacing experiments with cotton at Substai No. 12, Chillicothe, Texas, 1919 to 1924, inclusive. , One stalk to the hill. Average all Spacing, inches 1919 1920 1921 1922 1924 years tested * f between plants § Pounds Pounds Pounds Pounds Pounds Pounds '1 6 . . . . . . . . . . . . . . . . . . . . . . 315.35 345.21 297.63 114.75 277.29 270.04 12 . . . . . . . . . . . . . . . . . . . . . . 389.35 345.01 327.75 123.60 304.37 298.01 18 . . . . . . . . . . . . . . . . . . . . . . 370 35 381 31 324.64 140 64 322.60 307.90 24 . . . . . . . . . . . . . . . . . . . . . . 345 40 399 66 319.97 142 50 338 12 309 13 THE EFFECT OF SPACING ON THE YIELD OF COTTON 55 Investigations on the spacing of cotton have been conducted at Chilli- cothe since 1919. The spacing Work included only five spacings, 6, 12, i 18, 24, and 30 inches. Table 31 gives the yields of lint secured during the 5 years. The 30-inch spacing made the largest yield three years out of five, and the highest average yield, 317 pounds of lint to the acre, .for the five years of the experiment. The average yield of lint increased as the spacing increased. These results show that spacing ranging from s18 to 30 inches has given the most satisfactory yields in that part of the State. This rangeof spacing is recommended in farm practice of the region‘. Discussion of Results The general conclusions of the spacing work with cotton at each sub- irstation are given here for convenience in studying the experiment as a i whole. At College Station on the gray flat lands of East Central Texas the highest yields were obtained from the 9-inch and the 12-inch spacings over a period of 5 years, although practically as large yields were ob- itained where the plants were spaced 6 to 18 inches apart. These results gshow that a good stand of cotton for this part of Texas would be § 10,000 to 20,000 plants to the acre in ordinary rows. The results at Beeville on black loam soil in southern Texas show Ethat the spacing of 21 inches produced the highest average yield over "a period of 8 years. The 21-inch spacing is recommended, but spacing ithe plants 12 to 3O inches apart, or a distance allowing 6,000 to 15,000 plants to the acre, has given yields about as large as the yields of the 21-inch spacing. _ At Troup on the gray sandy lands of east Texas the largest yield for a period of 3 years resulted from the 30-inch spacing. The results indi- icate, however, that the spacing may vary from 18 to 36 inches without significant reduction in yield. At Angletonon the black soils of the Gulf Coastal Plains the 12-inch ‘spacing made the highest average yield for 8 years. About as large yields, however, were made where the plants were left 6 to 18 inches apart. i i The 21-inch spacing with 2 stalks to the hill produced the highest ‘yield for 6 years at Temple in the blackland belt, but the spacings rang- from 12 to 30 inches made yields almost as large. ' At Spur on the red landsof northwestern Texas the 12-inch spacing Tproduced the highest yield over a period of 8 years. The 12-inch spac- ing is recommended in farm practice, although the 9-inch, 15-inch, and j18-inch spacings gave about as satisfactory yields as the 12-inch spacing. ; The results’ at Lubbock on the High Plains in northwestern Texas show that the 12-inch and the 15-inch spacings made the highest aver- “age yield for 12 years. The results i.ndicate that the spacing may vary jfrom 6 to 21 inches Without significant decrease in yield. ? The spacing Work with cotton at Pecos was not conclusive, but the 56 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION l results secured indicate that spacing the plants 6 to 21 inches at will give the best yields under irrigation in western Texas. ,3 At" Nacogdoches on the red and gray sandy hill lands of eastern T the 27-inch spacing with 2 and 3 stalks to the hill made the highest '_ over a period of 6 years. Spacing the plants 18 to 33 inches apart, ever, gave yields about as large as the yield of_ the 27-inch spacing. At Chillicothe on the red lands of northwestern Texas the r spacing used, 30 inches, produced the highest average yield over a pe of 5 years. The results indicate that spacing the plants 6 to 12 a, apart gives too thick a stand for maximum production under the ~ ticular conditions. These results are not in agreement with those! cured at Spur, where 12 inches was the optimum spacing. ‘s These results on the spacing of cotton agree in general withr_ spacing work done in other states previous to 1914 and also with . quent work. The results obtained at Nacogdoches and at Troup, sandy soils in East Texas, and at Chillicothe on the red lands in no western Texas are exceptions. At-these three‘ points it was found w’ the optimum spacing was 27 to 30 inches, which is considerably than the optimumspacing found at the other points in Texas. , The Alabama Station (34) recommends spacing the plants 12 18 inches apart in rows of ordinary width. 1 The Arkansas Station (8, 9, 10) recommends that the plants .; spaced a hoe’s width apart, and states that the stand should be a’ 15,000 plants to the acre where the land produces 1,200 pounds of :{ cotton to the acre in the absence of the bo-ll weevil. _ _ The Georgia Station (102) found that “On a land capable yield of s} to 1% bales per acre the rows should be 3a} to 4 feet wide i the plants 12 to 18 inches apart in the drills, the narrower rows ‘p the closer spacing for the less productive soil.” The Mississippi Station recommends fairly close spacing, 6 to inches. At the Delta Branch Station (11) 8 inches was found- the optimum spacing. The Holly Springs Branch Station (7) that rows 3% feet apart with 2 to 3 stalks in bunches to the foot? valley lands, and rows 3 feet apart With 3 to 4 stalks to the footi hill land, were best for those conditions. The South Mississippi Br f: Station (40) also recommends close spacing. - " The North Carolina Station (84) found that spacing the plants; inches apart in ordinary rows gave the largest yields. It is stated ( “Results have shown that an increased yield and earlier maturity be expected from closer spacing thanhas been practiced in the p", A but a definite spacing or range of spacing is not given. _,- The South Carolina Station (113) has found “that the earliest and the highest yields are apt to be obtained from spacing which give 15,000 to 20,000 plants to the acre.” The Tennessee Station ('70) from 8 years’ work on cotton w; fouréd that spacing 6 to 18 inches in rows 3 feet apart gave the " yiel s. i- THE EFFECT OF SPACING ON THE YIELD OF COTTON 57 RESULTS SECURED WITH DEFERRED THINNING In 1913, O. F. Cook of the United States Department of Agriculture published a paper (25) in which he advocated a new system of cotton culture. This paper sets forth the theory that the development of the vegetative branches of the cotton plant can be suppressed or restricted by crowding the plants during early growth. This method is known as “single-stalk cotton culture.” In this paper Cook states: “The way to secure an early short-season crop of cotton is to thin the plants - later and leave them closer together in the rows than is now customary. Neither of these policies is advisable if used alone, but they give a real advantage when properly combined. Keeping the plants closer to- gether during the early stages of growth restricts the formation of vege- tative branches and induces an early development of fruiting branches.” In the same paper Cook reports that Durango cotton at Norfolk, Vir- ginia, in 1912, in a field planting thinned in the usual manner to ordi- nary distances made an average yield of 909 pounds of seed cotton to the acre, while alternate rows that were thinned late and left with plants closer together yielded at a rate of 1,3911 pounds, or about 53 per cent higher than the others. It is not clear from his results whether the increase in yield of the closely spaced cotton was due to the close spacing or late thinning, since there was not a check on the date of thinning or of the spacing. Cook has published other papers on this phase of cotton culture (27, 28, 29). The Texas Agricultural Experiment Station included late or de- ferred thinning in the general work on the spacing of cotton which it began in 1914. The object of this work was to investigate farther the theory advanced by Cook and to determine its applicability to condi- tions in Texas. Results with late thinning, however, were not obtained until 1916. _ . The field work in comparing normal and deferred thinning of cotton consisted of two series of plats. The rate of thinning, or spacing, was the same on both series of plats. The time of thinning, however, was different, as stated below: _ 1. Normal thinning‘. The series was thinned at the normal or usual time of thinning cotton, which, in general, is done when the plants have four to six leaves. 2. Deferred thinning. This series was thinned when the plants were about 6 inches high, or at the time squares began to form. All of the cultural methods, such as time and method of seed-bed preparation; time, method and rate of planting; varieties; and methods of cultivation, were the same for both series of plats. The only variable was the date of thinning. Late thinning was done at four stations: Angleton, Beeville, Chilli- cothe, and College Station. . cotton. 58 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION Results at College Station Table 32 gives the actual yields of lint obtained at College Stati for three years, 1916, 1917, and 1919. In 1916, which was a favorab year for cotton production, thinning the cotton at the normal time pr duced decidedly large yields than deferred thinning. In 1917, wh' was an unusually dry year, the deferred thinning made the high yields, particularly in the spacings from 6 to 18 inches, inclusive. D j ing the season of 1919, slightly larger yields were made in the deferr thinning, the largest being obtained from the spacing of 9 inches. I! 6-inch spacing gave the highest yield in the normal thinning. -; As an average for the three years, 1916, 1917, and 1919, the 6-inj spacing in the normal thinning produced the highest actual yield, 2; pounds of lint to the acre. The 6-inch spacing also produced the higrl, est yield, 208 ‘pounds, in the late-thinned cotto-n. There is very difference in the actual yields of the normal and deferred th1|fl~_'_;§~. where the plants are spaced 6 to 18 inches apart. Deferred thinni at greater distances, however, produced smaller average actual yie,_ than the normal thinning. When the normal and deferred thinnin are compared on the basis of the relative yield, Table 33, the deferr thinning has a slight advantage, especially in the 6-inch, 9-inch, 12-1111" 15-inch, and 18-inch spacings. For the wider spacings the normal t w; ning produced significantly larger yields. These results show that plan, should be thinned 6 to 18 inches apart at the usual time of thi 59 a2 2: 8 i“: 26 UGN JHOSNNW OUUZOU riOwwdww cmag 0J8 MN HOHMOQ m0 mficdiw vwukowvmfiwcm ~NEQOG Hi wvhsoo.» QOQQOO a3: m0 wwasoa u: mZUTn 0.~O< .2 mqmfiw N O T M SEO 82m o:O._. 553% 03¢ we ommhzé...“ C F o M fimumm w“ wwuwwfl Mfiw mfim: Ema... Wwmm Km.» Mmmmm BH“HMHMH“IHifHiununfiunuumm w h :5; m N32 was; so: wna 2Q .55 :5 mmfMyHmHHmmmxmHmmmmfwnfi E 2 2b: Z mm 8; mPfifi womfl .33 3.3 5N2. 3 mmm . . . . . . . . . . . . . . . RN W... C 1P8 N. 3E2 .53 wPEH 3.3 E8 w» 9N m. m . .. LI . . . . . . . . paw w 3 wfl w 3 “V2 flu m2 on Si M: mm we 3 .2. 8N S Nmm . . . . 4 . . . . . . . . . . . . . . . . . . .. 8 E q an“? w :42 $53 82: mmé 8m? 8.2m igwm m“IHmmmnxmmuuunHmw..w..@ .2 H N 8.2: m. $3.5 misfl E m: .38 .32. mafia i. EN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :2 T m .5 N2 w 2E2 $.92 Q m2 $93” ma? 33m 2 2m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nfi N m 2.22 m mflwwfl wfiwfi wPwfi Eaw Ram mm wmm mo m2 . . . a O ~ 3.8m fi mfiiw 8.2m 31mm Eh“. 3E an mum “K53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Iw G mfl ikmwm m mm E3 mm an an $3 mu um mm Q . ww mom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N . @ xnmfl wwasom xcwfl mwcsom mwcnom mvcsom munsom mwcsom mucsom “£56m @153 QQQBQQQ 3:05 iiomam % uufiouofl ~NEQOZ uuhhouon- wwfikoZ wwbouon- zwcioZ wobowofi 12:32 . . w umm$>< m2: :2 £2 T C m F E m N O I . T A T S T N E M I n E P x m L A R w L U C I R G A S A x E T o, 4. 3 O N N I m m U B 60 N~ vw m: aw . wa, . aw w ~n - mw ow _n fiw no~ no wm w mm m wm ow mm ma Nafl @w hw m 3 2 2w R. ow $ R: 8 . . . 5 o~ mm u >@ mm ~¢_ no _¢_ ..... aw h mm w mm fim m¢_ me mm‘ N» Nw N _m~ w <¢~ N>~ mw >¢_ w~_ mm am ~ mm~ m ma. mmfl »__ ~@_ _¢_ ¢¢_ mm m @_~ N -_ w_~ m_~ _¢~ -_ no ¢- m _m~ m w¢_ aw“ ¢__ _¢~ mm om >__ w wmfl ~ fimfi >m_ ¢@_ -_ fim m__ w__ - hm v mo_ mm o~_ mw on ..... . @~_ 58m Ax. ism & Ax. Q. Am. Q. Q. Ax. wobouofl 38.6 Z uobowofl wEEo Z wouhzofl 1295 Z wwbvuofl into Z . §S§H @253 $02 N madman “Roan 235cm om.mn" m_.¢@ @N.w@N ommho>< mflwfi hfimfl @_@H .@~@_ @=~.~_@_.@_@HA= @-pw.=os-w~m@=¢u =2 2: S 53m 2.5 .»m m<~muonn oiw|$%n- o%@u%waa -.~¢¢|u--¢.c-nn o 100w m w aon-‘u; u u! an $ - 0 to ~ . - v - - - ¢ ¢ I - - ¢ »¢-M 55m mwndom xcwfl mwnuom mwusom 225cm wwE-om mwdsom EVE-om music.» mwcsom wwcdom cokuouofl 125.52 uuuhomofl ~NRH~QZ wohnaofl 12:32 vobnflofl REQOZ Uopuowog ~GEMOZ maiwéfl flovguvfi mvfluflfimflmomfiw uwwmzé Mai mm: 22 £2 ma: Ea §2 .22 £13 £58m. d=m>oofi J .02 comfifimnsm Hm Q0300 no 5:55 v3.6.3“. wan 353a E wopuuww cofioo “c: we mwnsoa E 32% 3o< s.“ HA $4M. 63 N O T . T w w m2 .0: we s ..... ....... ...0.».....$.... :M.fi:......... 2 .. :22... m: 2 . . . . . . . . . . . . . . . . . . . . .58 D . . . . . . . . L w @ .-R._A-wi- .A.wA.w..w- -.%R~_...- . . . . . . . . . ... . . . . . . ... .fi@ m Q mw w NW FM . .®® ....... . PG MW NW . . . . . . . . . . . . . . . CHN Y Q uvw h fim 0Q ww QW . . “vm mm an: . . . . . . . . . . . . . . . . . . . . nualwfi é m . . . . . . . . . . . . . . . . . . . . . . .-@§ fl N N02 m 00 02 .3 0w 0w 3 .22 .02. mm . . . . . . . . . . . . . . . . . . . . . . . .2 \ T W N . .. .. . . . . . . . . . . . . . . . . . . . . . h a 0 N: :20... 2w m: Ma m: ..................... .5 N @ M . . . . . . . . . . . . . . . . . . . . . . . O m 0.3m Q0 00am .0 .0 .0 2 0. 2 x 2 Q. U. 0005020Q 205.82 w0E020Q 205002 000002002 105.52 w0E0H0Q R5502 00.20222 E552 % 0 I 0 l 0 @520 50025022 00:05 058mm S 082i @2500 $002! 2:500 $002M 25:00 0502" 2250A 2.00m 2.2 $2 maéfi . F 00223 m , 22 22 . 22 22 C Wu. 6N2 0:0 dmmw .22 .22 6050B .0_=>00m .2 .02 00202526 00 50300.? 05035 00000200 0cm 205.3: E 00.20000 50300 5: .20 “E03 022202 F . E . .2 @1272. E H T s1. _ . 64' BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STA Results at Substation No. 3, Angleton Deferred or late thinning of cotton was compared with no of‘ ning at Angleton for the 5 years, 1920 to 1924, inclusive. The? secured during this period are stated in Tables 36 and 37. Du 5 years there were only five instances in which any spacing in‘, ferred thinning pro-duced larger yields than the corresponding in the normal thinning. The 3-inch and 6-inch spacings in :., 33-inch spacing in 1923, and the 9-inch and 15-inch spacings ', in the deferred thinning made larger yields than the corres spacings in the normal thinning. In these five instances the larg of the deferred thinning are not significant. ~ ' The average actual yields for the 5 years, Table 36, show th, thinned at the normal time has produced larger yields tha1 thinned late. In fact, for the 3 years, 1922, 1923, and 1924, th average yield in the normal thinning was about the same as the-r yield, 148 pounds of lint to the acre, of the deferred thinnin actual yields reported in Table .36 were converted into relative“ which are set forth in Table 3'7. The highest average relative yi, obtained from the 6-inch and 9-inch spacings of the normal if In the deferred thinning, the 6-inch and 9-inch spacings also 1- highest yields. The results at Angleton show conclusively that thinning has given the highest yields and that-the plants sh, spaced 6 to 18 inches apart in ordinary rows for maximum n1 65 N 0 T T 0 C F 0 D L E I Y E H T N 0 G N I C A P s F 0 T C 2 E E H T 222.222 2K 2.2 22.2.8 2.2.2222 8.222 222.222 222.2 2.22.2 22.2.2.2 22222222 222222.32 8222 8&2 22w 222 222222 >22.222.~ 2.22 22% 2222 2222.22 2.2 5.2.2222 . . . . . . .. . . . . . .. mwuam 2222 22 2w mum 2222 22 2:22 222.22 2 2.2 8.2.2 2222.2 222.2222 2222.28 . . . . . .. 2.2.22 m mm? $222 2.22% 2222 22 2222.222 2222.222 2. 22.2.2 2222 2222.5 .2222. 22222222 . . . . . . . . . . . . . .. 2.2.2.222 22m 2m . 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SN E cc cc wc mc wcw cc wc cm cww .. .. R. cc IIIJN cc cc cc cc cc ccw cc cc Q “a 5 . . . . . .3 ccw . . . . . wN i. ccw E. cc wc cc ch cc m... ccw cc :5 wc cc . . . . .cw E wow ch cc cc 3 R. ccw cc cc cc v5 4 2 hc . . . .2 ch i: . ch ccw cc ccw 5 cmw cc Nc cc N2 R. cc . . . . . . .2 Nc m: cc cww cc 8 >2 Ncw Nc cc cc www B. . ....c cc ccw wc cww cc wcw cc E cc cc cc cc cc cww . . .c E cc C. cc mc mc 2. cow m» .5. m. E ....c x x x x x x x x x x x x x x uoboconw R55 2 woboconw H55 2 wuboconw R55 2 woboconw R552 uobocunw 12552 wobucwnw R55 2 wotoconw 525.5 2 “@525 53B 0 5.80% =4 vmcmfimcw §oowfl 55505 ccccwn .5555 §cown 5550a Qcccwfl 55:05 §ocwfl 55505 wvnofw ch . cwc w“. . cc ow .52 E . .5. cc . mmc . waaiw @9225 £2 m5: mm: 5N2 82 dZmBQE .52 0w cmcw 658E a82w=< .c .5 5554.5. .02 50Bw~mn5w cw 5030a c0 c5555 c3532. v55 i555 5m c0503 50300. c5: co n32» ofififlomw THE EFFECT OF SPACING ON THE YIELD OF COTTON 67 Results at Substation No. 12, Chillicothe pork in comparing normal and deferred thinning of cotton was con- ed at Chillicothe in 1919, 1920, 1921, 1923, and 1924. Only five rings, 6, 12, 18, 24, and 30 inches were used. The actual yields of t obtained are given in Table 38. The most striking feature of the I lts is that in the normal thinning the average yield for the 5 years - eased as the spacing increased. The 30-inch spacing of the normal ing made a higher average yield, 317 pounds of lint to the acre, =1 any other treatment in the experiment. In the deferred thinning, v- 18-inch spacing produced the highest average yield, 305 pounds of t to the acre. In every spacing the normal thinning produced a her average yield for the 5 years than the deferred thinning, except I the 12-inch spacing, where the two kinds of thinning produced equal ‘lds. The relative yields, obtained from the yields of lint in Table 38, are _' in Table 39. The 30-inch spacing in the normal thinning made w highest average yield. The 18-inch, 24-inch, and 30-inch spacings ' the normal thinning produced larger yields than any spacing in the - erred thinning. In the deferred thinning, the 18-inch spacing gave highest average yield. This indicates that if deferred thinning is the plants should be placed closer than if thinning is done at the rmal or usual time of chopping cotton. These results show that cot- u thinned at the normal time produced slightly larger yields than cot- ~- thinned later and that spacings varying from 18 to 30 inches gave tter results than closer spacing under conditions at Chillicothe. N 0 T. m T S T N E m R E P. X E L A R w L U C T. R G A S A X E T O, 4 3 O. N N I m m. U B 68 0.0.55 592m 2 8m 00.0mm 2.02 $.02 50.8». 590mm 2 5mm 00.5% omflmm m.» $0 .. . . . . . . . . . . . .00 50.0%.. 2.2m 00.5.» 5.0mm $.03 8.52 :28». 8.5m 00.55.. 005a». 00.03 002.5% . . . . . 00.53 00.8w .0555 8.5m 00.0»: $.03 5.22m 00.5w 305$ 8.5x... 8&5 @908 . . . . . . . 510% 50.3w 5.8m 50.8w 852 8am. 3.5m E230 00.000 8.43m 00.3». @0550 . . . . . . N», 0%.. 3.5m 85R 55R 05m: 53v: 8.8m R 0% 00.8w mm 2m . . . . V 555cm mw550m 355cm 555cm 5.55m 255cm 555cm ww550m 2.55m 20550m 555cm 555cm vobomonm E500 2 ~00500~0Q 5550 2 wobfiofl F5502 wobomofi 25550 2 uPCMEQ R550 2 00.20222 104E‘ 02 .5525 5002505 wocgfimfiowmm 00.203 500% 5N2 5: 2N2 0N2 22 =5 50.“ 0022/4 . 4m: 0.5 o» 513m 050 .0>EB05 .52 3 2mm £36m. .05000==5U Nm .02 50$3mA5w 0w 50300 m0 95555 50.55305 55m R5505 5 005500» 50300 05: m0 £05505 5 30E 050< an 55555 69 N 0 T T 0 C F 0 D L E I Y E H T N 0 G N I C A P S F 0 T G E F F E E H T mm 8: 8 NZ 5: m: m8 i: x: 2: 8 8 @...IJZ. U . mxquam 8 m: 8 2: 9: 2: 8 8: 8 8: 8w 8 q . . . . ...: ffi z: n: 8 2: z: i: 8 z: 8.: 8: 2: Q: “rump . ... 1:2 8 8 8 8 8 8, 8 8: 2: 8 Q: c: . . . . ........~: .8 8w w» 8 3 m» .8 8 é 8w w I x x x x x x x x x . x x x @8525 18.5.82 wobouofi 1280 Z wQEBQQ 12:20 Z wvuhowofl R552. wobflufl 12:32 wvhhomofl 35.52 ow $23" 8252. “N521 @252: $02M @259: $02" $56.: wxoofifl 8:52.: 832a c0033: monucfimnmowam 8.68/4 ~m . own mm . 3.: C. . 8m mm . m8 3 . $8 v8: , N8: ~N2 8.: ~32 d3 of 3 53m 0:0 afiwfioi Jam: 3 m3: “£88k dfioozanU .N~ .oZ uoflgmnsm an aofioo at? mucvzhuomxo 2:22: E wohsuom cofioo E: Mo .8301» ofiiflofl .8” Hdmiwh. . 70 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION A Discussion of Results The results secured in comparing normal and deferred thinnin cotton show in general that normal thinning produced larger yields deferred thinning. These results are in accord with contempora work on this phase of cotton culture. Ayres in Arkansas (9, 10) A, later in Mississippi (11,12); Brown and Ames (21) and Brown é 23) in Mississippi; McClelland (63) in Georgia; Garrett (45) and g ter (53) in Louisiana; and Hall and Armstrong (49) in South C lina, who worked with normal and late thinning of cotton, during “ time covered by the work in Texas, have reported results similar to obtained at this Station. Letteer (60, 61) at San Antonio, Texas, obtained better results With early thinning. " Cook in Virginia (25, 28), Oardon in Louisiana, Arkansas, and i" Carolina (24), Blair in California (19), Meade in Texas (67), Hastings in Texas (51) have reported results showing that late ning of cotton gave larger yields than cotton thinned at the usual "_ Usually they had two series of plats, one with plants closely spaced f thinned late, and the other with plants spaced widely and thinned -= In most cases they did not have any checks on the date of thinni of the spacing. At that time it was not clear from their results =49; the larger yields of the late-thinned cotton were due to the late w, ning or to the closer spacing, since they had no check on either the of thinning o-r of the spacing. The results secured at this Station show conclusively that early-th a cotton produced larger yields than late-thinned cotton. In comp _ these results with those of Cook, Cardon, Blair, Meade, and :2 '7 it appears that the larger yields they obtained from the “single- I method resulted from the close spacing rather than the late th' i-j since the work at this Station shows that closely spaced cotton 1" early produced larger yields than similarly spaced cotton thinned i” In studying “single-stalk cotton culture” and widely spaced co Ricks and Brown in Mississippi (107) obtained larger yields with.‘ “single-stalk” method. In the rows with wide-spaced plants there pf 54.9 plants to the row and 95.6 plants to the row in the “single- rows. They were of the opinion that the larger yields of the “BU: stalk” method were due to the close spacing, since previous wor the Mississippi Station covering a period of eight years had shown , close spacing had given larger yields than wide spacing. A careful review of the literature and an analysis of the data. sented on late or deferred thinning do not show any experimental dence that late thinning of cotton increases the yield as compared I normal thinning. Present knowledge indicates that the usual or n A time of thinning as now commonly practiced is safer, and that the :5 ing should be that found best under the particular conditions consideration. THE EFFECT OF SPACING ON THE YIELD OF COTTON 71 SUMMARY QIn these experiments it was found that close to medium spacing, 6 ‘ 21 inches, produced the largest yields in general in the different parts the State, except in eastern Texas 0n the sandy lands, where com- ratively wide spacing, 2'7 to 30 inches, gave the best results. Twelve : hes was the optimum spacing at Angleton, Spur, and Lubbock; 9 to inches at College Station; 21 inches at Beeville and Temple; 2'7 inches ‘Nacogdoches; and 30 inches at Troup and Ohillicothe. A satisfac- v range of spacing, in addition to the optimum spacing, is given for " h substation. IfThese results show that the cotton plant has the ability to adjust elf to produce satisfactory yields within a comparatively wide range - spacing. i In general early-thinned cotton produced larger yields than. late- "nned cotton. At Angleton and Beeville early-thinned cotton pro- ced decidedly larger yields than late-thinned cotton. No evidence f.- . obtained to show that late thinning of cotton is better practice than p ly thinning as now commonly practiced. ' ACKNOWLEDGMENTS i ‘Mr. A. B. Conner, Vice-Director, instituted the work on the spacing - cotton and had general supervision of the project until 1923. The old experiments were conducted and the data collected by the super- tendents of substations as follows: Mr. Louis Wermelskirchen and r. E. W. Geyer, former superintendents of the Main Station Farm, llege Station; Mr. R. A. Hall, Superintendent, and Mr. E. E. Bin- u» and Mr. I. E. Cowart, former superintendents of Substation No. __ Beeville; Mr. W. S. Hotchkiss, Superintendent, Substation No. 2, Ioup ; Mr. V. E. Hafner, Superintendent, and Mr. N. E1. Winters, for- er superintendent of Substation No. 3, Angleton; Mr. A. K. Sho-rt Mr. D. T. Killough, former superintendents of Substation No. 5, mple; Mr. R. E. Dickson, Superintendent, Substation No. '7, Spur; _r. V. L. Cory and Mr. R. E. Karper, former superintendents of Sub- tion No. 8, Lubbock; Mr. J. W. Jackson, former superintendent of bstation No. 9, Pecos; Mr. G. T. McNess, former superintendent of bstation No. 11, Nacogdoches; and Mr. A. B. Oron, former super- tendent of Substation No. 12, Chillicothe. t‘ The author appreciates the opportunity to use the data. 72 <1) <2) <3) <1) <5) <6) <1) <8) <9) <10) <11) <12) <13) (14) (15) (16) (17) y‘ BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATIO REFERENCES Ames, C. T. 1920. Report of cotton experiments at the A Springs Branch Experiment Station, seasons 1919 and; Miss. Agr. Exp. Sta. Bul. 192, pages 9 and 10. ' .Ames, C. T. 1920. Report from Holly Springs Branch B; ment Station for 1915 to 1920, inclusive. Miss. Agr.‘. Sta. Bul. 193, pages '7 and 8. - Ames, C. T. 1921. Report from Holly Springs, Branch fr ment Station for 1921. Miss. Agr. Exp. Sta. Bul. 202,5 12 and 13. ‘- Ames, C. T. 1922. Report from Holly Springs Branch E -: ment Station for 1922. Miss. Agr. Exp. Sta. Bul. 211, 10 and 11. i Ames, C. T. 1923. Report from Holly Springs Branch ment Station for 1923. Miss. Agr. Exp. Sta. Bul. 220, Q 13 and 14. Ames, C. T. Station. page 51. Ames, C. T. 1924. Report from Holly Springs Branch ment Station for 1924. Miss. Agr. Exp. Sta. Bul. 223, i’, 14 and 15. “ 1923. Annual report of Holly Springs B In Thirty-sixth Annual Report Miss. Agr. Expg. Ark. Agr. Exp. Sta. Bul. 181, pages 23-25. Ayres, W. E. 1918. Cotton spacing experiments. Ark. Exp. “Sta. Bul. 153. Ayres, W. E. 1919. Cultural experiments with cotton. _ Agr. Exp. Sta. Bul. 161. 3 Ayres, W. E. 1921. Cotton experiments. Miss. Agr. Exp.: Circular 42, pages 5 and 6. Ayres, W. E. 1923. Cotton experiments, 1922, Delta B‘ Station. Miss. Agr. Exp. Sta. Bul. 215, pages 11 and 1i Ballard, W. W. and Simpson, D. M. 1925. Behavior of planted at different dates in weevil-control experimen Texas and South Carolina. U. S. Dept. Agr. Bul. 1320, w, 23-29. ‘ Balls, W. L. and Holton, F. S. 1916. Spacing experiments f Egyptiancotton, 1912. Phil. Trans. Roy. Soc. London; B, 206, No. 327, pages 103-180. (Original not seen. Ab in Exp. Sta. Rec. V. 36 (1917), page 36.) Barre, H. W. 1924. Boll weevil investigations in 1923. p v Agr. Exp. Sta. Cir. 31, pages 19 and 20. f; Barrow, D. N. 1894. Experiments in width of rows and.“ . A tance. In La. Agr. Exp. Sta. Bul. 28 (Second Series), 968 and 969. . "1 Blackwell, C. P. and Buie, T. S. 1924. factors affecting earliness and yield. S. C. 219, pages 34-37. Cotton produ Agr. Exp. Sta. a THE EFFECT OF SPACING ON THE YIELD OF‘ COTTON 73 Blair, R. E. 1915. The work of the Yuma Reclamation Project Experiment Farm in 1914. U. S. Dept. Agr., B. P. I., W. I. A. Circular 7, pages 9-12. . Blair, R. E. 1918. The work of the Yuma Reclamation Proj- ' ect Experiment Farm in 1917. U. S. Dept. Agr., B. P. 1., W. I. A. Circular 25. Brown, H. B. 1916. Cotton experiments, 1915. Miss. Agr. ' a Exp. Sta. Bul. 173, pages13 and 14. a Brown, H. B., and Ames, C. T. 1918. Cotton experiments, * 1917. Miss. Agr. Exp. Sta. Bul. 184, pages 10, 11, and 21. Brown, H. B. 1919. Cotton experiments, 1918. Miss. Agr. a Exp. Sta. Bul. 186, pages 12-14, and 17. Brown, H. B. 1923. Cotton spacing. Miss. Agr. Exp. Sta. Bul. 212. Cardon, P. V. 1918. Experiments with single-stalk cotton cul- ture in Louisiana, Arkansas, and North Carolina. U. S. Dept. Agr. Bul. 526. Cook, O. F. 1913. A new system of cotton culture. U. S. Dept. Agr. B. P. I. Circular 115, pages 15-22. Cook, O. F. 1913. Cotton problems in Louisiana. U. S. Dept. Agr , B. P. I. (Misc. Pub.), Circular 130. Cook, O. F. 1914. Single-stalk cotton culture. U. S. Dept. Agr., B. P. I. (Misc. Pub.), 1130. Cook, O. F. 1914. A new system of cotton culture and its ap- plication. U. S. Dept. Agr. Farmers’ Bul. 601. Cook, O. F. 1919. Experiments in spacingcotton. In Jour. Am. Soc. Agron., Vol. 11, No. 7, pages 299-303. DeLoach, R. J. H. 1913. Report on cotton cultivation in 1912. I n Bul. Ga. State College of Agr., Vol.1, No. 2. Dickson, R. E. 1917. Progress Report, Substation No. 7, Spur, Texas, 1909-1914. Tex. Agr. Exp. Sta. Bul. 217, page 22. Duggar, J. F. 1897. Experiments with cotton. Ala. Agr. Exp. Sta. Bul. 76, pages 14 and 15. Duggar, J. F. 1898. Experiments with cotton. Ala. Agr. Exp. Sta. Bul. 89, pages 10-12. Duggar, J. F. 1899. Results of experiments on cotton in Ala- bama. Ala. Agr. Exp. Sta. Bul. 107, pages 221-224. , Ewing, E. C., and Ricks, J. R. 1914. Cotton experiments, 1914. f‘ Miss. Agr. Exp. Sta. Bul. 169, page 7. - Ferris, E, B. 1904. Report of work at McNeill Branch Sta- ’ tion for 1903. Miss. Agr. Exp. Sta. Bul. 83, page 26. Ferris, E. B. 1920. Report from South Mississippi Branch Ex- periment Station for 1918 to 1920. Miss. Agr. Exp. Sta. Bul. 194, page 14. ' Ferris, E. B. 1920. Cotton growing in South Mississippi. Miss. Agr. Exp. Sta. Bul. 196, page 8. 74 BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION (39) (40) (41) (43) (43) (44) (45) (45) (47) (48) (49) (50) (51) (52) (53) (54) (55) (55) (57) Ferris, E. B. 1922. Report from South Mississippi Branch {-9 periment Station for 1921. Miss. Agr. Exp. Sta. Bul. 2 page 8. - ' 5 Ferris, E. B. 1924. Cotton experiments, South Mississi Branch Experiment Station. Miss. Agr. Exp. Sta. Circ f_ 56, page 6. ‘l Ferris, E. B. 1925. Cotton experiments, 1925, South Mis sippi Branch Experiment Station. Miss. Agr. Exp. Sta. i cular 63, page 6. Fox, J. W. 1907. Report of work at the Delta Station 1906. Miss. Agr. Exp. Sta. Bul. 106, page 3. . _, Fox, J. W. 1907. Report of the Work at the Delta Station g 1907-08. Miss. Agr. Exp. Sta. Bul. 119, page 8. Fox, J. W., Ricks, J. R., Ewing, E. C., and Walker, G. B. 194i Recent cotton experiments. Miss. Agr. Exp. Sta. Bul. .1 pages 13, 29. ‘ Garrett, J. B. Thinning cotton to different stands and at l1 ferent times. In La. Agr. Exp. Sta. Twenty-eighth Ann" Report, page 27. ? Ga. Exp. Sta. Thirty-fourth Annual Report, 1921, page 7. Ga. Exp. Sta. Thirty-fifth Annual Report, 1922, page 7. , Ga. Exp. Sta. Thirty-seventh Annual Report, 1924, page 7' Hall, E1. E., and Armstrong, G. M. 1926. Cotton experi; at Florence. S. C. Agr. Exp. Sta. Bul. 225, pages 12-21.!- Hastings, S. H. Work of the San Antonio Experiment F 9 in 191.3. U. S. Dept. Agr., B. P. I., Work of the San r- , Experiment Farm, 1913. i Hastings, S. H‘. Work of the San Antonio Experiment p, in 1914. U. S. Dept. Agr., B. P. I., work of the San An’ Experiment Farm, 1914. ‘ - Hastings, S. H. 1916. The Work of the San Antonio E ment Farm in 1915. U. S. Dept. Agr., B. P. I., W. I. A. , cular 10, pages 13 and 14. Hester, C. E. 1917. Cotton thinning test. In La. Agr. ~I Sta. Twenty-ninth Annual Report, page 22. j. Karper, R. E. 1917. Progress report, Substation No. 8, book, Texas, 1909-1914. Tex. Agr. Exp. Sta. Bul. 219, s’ 25-27. 4' Lee, J. G. ‘ 1889. Report of the North Louisiana Experi v Station, Calhoun, La. La. Agr. Exp. Sta. Bul. 27 Series), pages 473 and 474. Lee, J. G. 1891. Results of 1890 obtained on the North isiana Agricultural Experiment Station. L.a. Agr. Expg Bul. 8 (Second Series), pages 190 and 191. i Lee, J. G. 1892. Results of 1891 obtained on the North . isiana Experiment Station, Calhoun, La. La. Agr. Exp. Bul. 16 (Second Series), page 448. THE EFFECT OF ‘SPACING ON THE YIELD OF COTTON 75 Lee, J . G. 189-3. Report of results for 1892 at Calhoun, La. La. Agr. Exp. Sta. Bul. 21 (Second Series), page 692. Lee, J . G. 1894. Report of results for 1893 at Calhoun, La. La. Agr. Exp. Sta. Bul. 29 (Second Series), page 1027. Letteer, C. R. 1917. The work of the San Antonio Experi- ment Farm in 1916. U. S. Dept. Agr. B. P. 1., W. I. A. Cir- cular 16, pages 10-12. Letteer, C. R. 1918. The work of the San Antonio Experi- ment Farm in 1917. U. S. Dept. Agr., B. P. 1., W. I. A. Cir- cular 21, pages 12-14. ‘ McBryde, J . M. 1891 Cotton experiments with varieties and with fertilizers. Clemson Agr. College and Exp. Sta. Bul. 2 (New Series), pages 92 and 93. McClelland, C. K. 1919. Cotton and corn cultural tests, and variety tests of 1917 and 1918. Ga. Exp. Sta. Bul. 128. McKeever, H. G. 1924. Spacing experiments with Acala cot- ton in Southern California. J our. Agr. Res. Vol. 28, No. 11, pages 1081-1093. a McNess, G. T. 1918. Progress report, Substation No. 11, Nac- ogdoches, Texas, 1909-1915. Tex. Agr. ‘Exp. Sta. Bul. 237, page 12. - McNess, G. T. 1919. Report of experiments at Substation No. 11, Nacogdoches, Texas. Tex. Agr. Exp. Sta. Bul. 254, page 13. Meade, R. M. 1915. Single-stalk cotton culture at San Antonio. U. S. Dept. Agr. Bul. 279. Miss. Agr. Exp. Sta. Thirty-fifth Annual Report, 1922, pages 47 and 48. Miss. Agr. Exp. Sta. Thirty-seventh Annual Report, 1924, pages as, 41. Mooers, C. A., and Robert, S. A. 1923. Cotton culture in Tennessee. Tenn. Agr. Exp. Sta. Bul. 127, pages 8-10. Nelson, Martin. 1918. Nature and Progress of the work of the Agricultural Experiment Station. Ark. Agr. Exp. Sta. Bul. 158, pages .32 and 33. Newell, Wilmon. 1909. What constitutes a perfect stand of cotton when fighting the boll weevil. La. Crop Pest Commis- sion Circular 25. Newman, W. H. 1888. Experiments with cotton, 1888. (Ala.) Canebrake Exp. Sta. Bul. 4, page 6. Newman, J. S. 1890. Field experiments in 1889. In Ala. Agr. Exp. Sta. Bul. 16 (New Series), page 19. Newman, J. S., and Clayton, J as. 1891. Experiments with cotton. Ala. Agr. Exp. Sta. Bul. 22 (New Series), pages 11-15. Newman, J . S., and Clayton, Jas. 1891. Cotton. Ala. Agr. Exp. Sta. Bul. 33, page 6. ' (89) (99) (99) (91) (99) (93) (94) (95) (96) (97) (98) <99) (100) (101) ,'(102) BULLETIN NO. 340, TEXAS AGRICULTURAL EXPERIMENT STATION? N. C. Agr. Exp. Sta. Tenth Annual Report, 1888, pages 12 N. C. Agr. Exp. Sta. Forty-fourth Annual Report, 1921, p' N. C. Agr. Exp. Sta. Forty-fifth Annual Report, 1922, pagi N. C. Agr. Exp. Sta. Forty-seventh Annual Report, 1924,’ 38. i N. C. Agr. Exp- Sta. Bul. 247, page 8 (1925). Okla. Agr. Exp. Sta. Thirty-second Annual Report, 1922, p. Okla. Agr. Exp. Sta. Biennial Report for 1922-1924, page , Pate, W. F., and Winters, R. Y. 1921. 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Thirty-third Annual Report, 1920, page 63. Tex. Agr. Exp. Sta. Thirty-fourth Annual Report, 1921, pages 25,29,41. i, Tex. Agr. Exp. Sta. Thirty-sixth Annual Report, 1923, page 19. s Tex. Agr. Exp. Sta. Thirty-eighth Annual Report, 1925, page 28. True, A. C., et al. 1896. The cotton plant, its history, botany, chemistry, culture, enemies, and uses. U. S. Dept. Agr. Of- fice of Experiment Stations Bul. 33, pages 271-278. Walker, G. B. 1912. Report of Work at the Delta Branch Ex- periment Station for 1911. Miss. Agr. Exp. Sta. Bul. 157, page 20. l‘ Walker, G. B., and Ayres, W. E. 1921. Cultural experiments with cotton. Miss. Agr. Exp. Sta. Circular 35. I Welborn, W. C. Cotton and corn experiments for 1908. Tex. Agr. Exp. Sta. Bul. 120, page 15.