COTTON-SPACING EXPERIMENTS 39 
0.108 pound in favor of the unthinned rows. This difference is more 
than five times the probable error and may be regarded as significant. 
The mean difference corresponds to an increase of 9.2 per cent in the 
unthinned rows, whereas the difference between the mean yields is 
0.58 pound, corresponding to an increase of 9.8 per cent. 
The row yields are shown graphically in Figure 18 and indicate the 
superior fruiting of the unthinned rows over the blocked-out rows. 
In the 1925 experiments the rows with the highest number of plants 
produced more cotton in every comparison. 
TABLE 18.—Comparative yields in cotton-spacing experiment with unthinned and 
hlocked-out rows, Greenville, Tex., 1925 
[The rows, which were 100 feet long, were planted Apr.13 and thinned June 1 (when the plants were 
about 514 inches high and were bearing about seven true leaves). The first picking was Sept. 
4 and the second one Oct. 17] 
| 
| Section 1 Section 2 Section 3 
| @ | Yield ofseed cot-| { | Yieldofseedcot-| | | Yield of seed cot- 
| 4 ton (pounds) S | ton (pounds) = | ton (pounds) 
Spacing is Pea 2 
Seis ested n eihieer His ped fecal) 
mace Peete ik SS ieee eet he De ee hea (eee 
Bl | Se) ee | S | 8 | se) sa) Ss Si 58 | 84) 
OR ee BS aoe SO Sloe lio Se Bay acre SS 
4 a/®arg | A} BlMeal ea | yl BlBal - 
We Ce | ee aE Lesh SEE Sah: 
1 | ot 2.6| 1.0] 3.6] 496/ 24) 11] 3.5) ZA 26) 1.4| 40 
Inth} DWE |e AB te Be ic 4420 Oe oo 833i ( 500) |, 52.8 bed dela? 
Duthinned (block 4) “ne) 4541 -93| 71 20 | 44|-20| .9|°29| 458| 20| <9) 39 
Pee Shor O5e| <8") 933) 512 42.6 | Oo | Sea | 405 Orato ke 40 
—__ ———-. /___—_ —_ | — 
ROlal eens oe ens 1,841 | 9.8} 3.3/ 13.1 [1,904 | 9.5] 3.7 | 13.2 1,873 | 11.4] 4.7] 16.1 
IE 181 | 2.0 -9| 28] 230| 201 .6| 26 213 paleara a: 20 
De ee SU at 2014-16! |e1A Faecal 213i Tel oreo 
Blocked (block 2)____. NS ieete e204 12 | 82) 2 19) 11) 80) 225) 2a) og) oad 
(ee 2082.4) 98 213.2) 216) 1.91.9 | 2.81216 | 21/25 | 26 
otal ese ioe 754| 8.6| 3.7|123| 901] 7.4] 36] 11.0| 867| 87} 29} 11.6 
QB | 30] 26] 8 | 34] 500] 26] 10] 3.6! 464) 24) 6 | 3.0 
oak é SO eR | N08. PA37 Were | 8 | 289 BT RIE 355 
Unthinned (block ale | 471} 251 .6| 3.1] 458; 22| .8| 3.0] 587| 22] .6| 28 
Ad | 428 26 e935 |) 409 | 25) 1.01 3.5 | 528 | 28)- .8) 3.6 
GotaPs. 2 2 |.---/1, 731 | 9.8| 3.1 | 12.9 |1,804| 9.4] 3.6 | 13.0 2,099} 101| 28) 129 
if | 229 | PS awa ete obhe|  2O5H fet e7 te 9.15206] 29854) 22 aaleg 5 1k 2. 6 
ae ote Onl t 61 526) 214 | ele 14 9.1 | Ok | De Bt ao 
Blocked (block 4)-----)3 | io4|. 20:| ‘8| 28| 205| 14/ 12! 26| 146] 20| ‘8| 28 
4 | 1838] 1.7] .7| 24) 162] 1.4] 12] 26] 183| 23) .5| 28 
Rabat 2 es |....| 820] 7.5] 2.8/10.3| 786| 62] 4.7] 10.9] 788| 90} 24] 114 
i | ADrale a6) bee [She | ab7Laokae sive M4 91122497 |) sion to |e a9 
: Se} SF |) 2.4 SSuletoae, | e4OMale S| als la eSele ll ASO oo 5ae ca Selenos 
Unthinned (block 5)--/)3 | 517| 29| 11/ 33! 438| 21| 13| 34! 528] 24| 12] 3.6 
4} 4581 251 1.0) 3.5 | 428) 22b10) 3.21 464) 2.4] RI 35 
Motatete ci 25)? |---|, 750] 9.7] 41 13.8 {1,700 | 83] 5.4/ 13.7 /1,919/ 103] 40) 143 
Wisc oio Ie te |) ons oon eo ae) a7) ab | De | hele aere 
se p2eel ATO lode Gals 2 Gis 240 14 ha le orl 3 3:1. 9561-9 4 lr TLOnmaed 
Blocked (block 6)-....13 | 599| 17| ‘3| 25/ 219) 20] 12| 32| 23| 22! 11 Pees 
ae ont | abi os ile 4 2199 126: 229: 1h2..58| 2601-2. Osa oM eore 
Bihabeae oot, ---- g31 | 6.9] 29] 9.8] 880] 76| 4.1] 11.7 |1,004| &7| 3.8] 12.5 
1 
SUMMARY OF YIELDS FROM SPACING EXPERIMENTS 
In the results of the 18 experiments conducted during the 5-year 
period from 1921 to 1925, inclusive, there is an outstanding tendency 
toward higher yields from rows with plants spaced less than 12 
inches apart. In this series of experiments there has been only one 
