6 



BULLETIN 279, IT. S. DEPARTMENT OF AGRICULTURE. 



WHle comparative yields comprise the most important consid- 

 eration in such tests as long as the quality of the fiber is not injured 

 in the system giving the highest yield, it is important to know what 

 factors influence productiveness. Since the success of single-stalk 

 culture depends primarily on the suppression of vegetative-branch 

 development, it is important to know how conditions of climate 

 and culture affect the growth of these branches. The rate of flower- 

 ing and the setting of bolls are directly associated and have con- 

 siderable bearing on the yields. The number of locks in the boll is 

 not important so long as good yields are obtained, but a great 

 reduction in the size of bolls would, of course, be undesirable under 

 any system of culture. The distance to which plants spread between 

 rows, especially near the ground, is important, since it may affect 

 cultivation, picking, etc., and the distance apart rows should be 

 planted may be limited by this feature. Data on all of these points 

 were secured only in sections A and B, which included the largest 

 part of the field. On some of the points, however, data were obtained 

 from all sections. 



DEVELOPMENT OF VEGETATIVE BRANCHES. 



During warm and favorable spring weather in the region of San 

 Antonio, cotton plants in wide-spaced rows develop five or six 

 vegetative branches, but if the weather remains cool only two or three 

 branches may develop. Though the development of vegetative 

 branches was restricted more than usual by low temperatures in the 

 season of 1914, it was possible by leaving the plants crowded in the 

 rows to induce a further reduction in the number of branches. This 

 can be clearly seen in Table I, which presents the average number of 

 vegetative branches on plants in wide-spaced and single-stalk rows 

 of Acala cotton in sections A and B. These averages represent the 

 census from 25 consecutive plants in each of the rows. 



Table I. — Average number of vegetative branches on plants invnde-s paced and in single- 

 stalk rows of Acala cotton in sections A and B, San Antonio, Tex., 1914. 



Alternate single rows (section A). 



Alternate 4-row blocks (section B). 



Single-stalk 

 rows. 



AVide-spaced 



rows. 



Single-stalk Wide-spaced 

 rows. rows. 



Row 

 No. 



Average 



of 25 

 plants. 



Row 

 No. 



Average 



of 25 



plants. 



Row 

 No. 



Average 



of 25' 

 plants. 



Row 

 No. 



Average 

 of 25 



plants. 



3 

 5 



9 



0.48 

 .56 

 .50 

 .•40 



4 

 6 

 8 

 10 



1.56 

 1.60 

 1.72 

 1.64 



62 

 63 

 64 

 65 



0.40 

 .64 

 .60 

 .64 



58 

 59 

 60 



61 



1.56 

 1.68 



2.00 

 1.20 



