26 



BULLETIN 1320, U. S. DEPABTMENT OF AGBICTJLTTJEE 



The average number of squares formed on 10 plants of each spac- 

 ing is shown in Table 14. The unthinned plants averaged 10.6 

 squares each on June 27, as compared with 10. 1 squares on thinned 

 plants. On August 9, when the final record of all squares formed 

 was obtained, the thinned plants averaged 34 and the unthinned 

 plants 25.4 squares per plant. 



The greater fruiting capacity of individual plants when two plants 

 are left in hills does not represent the relative fruitfulness of thinned 

 and unthinned cotton. When equal areas of each spacing are com- 

 pared, the greater number of plants in unthinned rows, usually more 

 than offsets the difference in fruiting capacity of individual plants. 

 This is illustrated in Plate III by the number of bolls set on equal 

 sections of rows of thinned and unthinned plants. 



PRODUCTION OF FLOWERS ON THINNED AND ON UNTHINNED ROWS 



Daily records of the number of flowers were obtained from July 2 

 to July 7 and at 2-day intervals thereafter until August 6. These 

 records were obtained from a 50-foot section of rows of thinned and 

 of unthinned plants, each section being representative of similarly 

 spaced plants throughout the test. There were 144 plants in the 

 section of unthinned cotton and 98 plants in the thinned section. 

 The data of flower production are given in Table 15. 



Table 15. — Flowers counted in 50-foot sections of roivs of cotton unthinned com- 

 pared with those on plants thinned to two in a hill with the hills 12 inches apart 

 at San Antonio 



Date, 1923 



Un- 

 thinned 



Thinned 



Date, 1923 



Un- 

 thinned 



Thinned 



Date, 1923 



Un- 

 thinned 



Thinned 



July 2 



July 3 



July 4 



July 5 



July 6 



July 7 



July 9 



July 11 



30 

 28 

 22 

 31 

 52 

 33 

 62 

 50 



10 

 8 

 14 

 11 

 17 

 22 

 30 

 17 



July 13 



Julvl5 



July 17 



July 19 



July 21 



July 23 



July 25 



July 27 



64 

 69 

 64 

 54 

 46 

 41 

 43 

 36 



46 

 41 

 58 

 48 

 41 

 35 

 41 

 41 



July 29 



July 31 



Aug. 2 



Aug. 4 



Aug. 6 



Total... 



30 



19 



4 



3 



1 



23 

 21 

 17 

 14 

 11 



782 



566 



Although individual plants of thinned cotton have a greater fruit- 

 ing capacity than unthinned plants, comparisons of equal areas of 

 each spacing show that a larger number of flowers were produced 

 by the unthinned plants. A total of 782 flowers was counted on the 

 50-foot section of unthinned cotton, as compared with 566 flowers 

 on an equal section of thinned plants. The difference of 216 more 

 flowers on the unthinned cotton represents an increase of about 

 38 per cent in favor of the unthinned plants in this test. 



A greater degree of earliness of the unthinned plants is indicated 

 by the number of flowers produced during the first part of the flower- 

 ing period. A total of 372 flowers was recorded on the unthinned 

 plants during the period from July 2 to July 13, as compared with 

 175 flowers on the thinned plants during the same period. 



WEEVIL DAMAGE TO BOLLS 



A record of the extent of weevil injury to bolls was obtained from 

 two 50-foot sections of rows in the late-planted cotton. On August 



